Category Archives: A-Rated

“A”
A pest of known economic or environmental detriment and is either not known to be established in California or it is present in a limited distribution that allows for the possibility of eradication or successful containment. A-rated pests are prohibited from entering the state because, by virtue of their rating, they have been placed on the of Plant Health and Pest Prevention Services Director’s list of organisms “detrimental to agriculture” in accordance with the FAC Sections 5261 and 6461. The only exception is for organisms accompanied by an approved CDFA or USDA live organism permit for contained exhibit or research purposes. If found entering or established in the state, A-rated pests are subject to state (or commissioner when acting as a state agent) enforced action involving eradication, quarantine regulation, containment, rejection, or other holding action.

A-Rated, Hymenoptera, Insects, Mites & Earthworms

Tawny Crazy Ant | Nylanderia fulva

Some Tawny Crazy Ants

California Pest Rating  for
Tawny Crazy Ant | Nylanderia fulva
Hymenoptera:  Formicidae
Pest Rating: A  

PEST RATING PROFILE

Initiating Event:

Several Nylanderia species have been intercepted 31 times in 2017 by CDFA through various regulatory pathways. Nylanderia fulva, the tawny crazy ant is an invasive species that has invaded the southern states of Texas, Louisiana, Mississippi, Alabama, Florida and Georgia (Wang et. al, 2016). Nylanderia species have been rated as Q.  A pest rating proposal is needed to assign a permanent rating.

History & Status:

Background:  Ants in the genus Nylanderia are relatively small, pale yellow to black. Nylanderia fulva in the U.S. were originally identified as Paratrechina sp. cf. pubens and later revised to N. fulva. The true N. pubens is also an invasive pest, but is apparently restricted to southern Florida. Worker ants of these two species cannot be distinguished morphologically, so clear identification requires examination of male specimens.

 Nylanderia fulva is also known as the crazy ant due to its quick and erratic movement. It is a small, reddish brown ant that forms huge colonies, and is a serious nuisance pest. (MacGown and Layton, 2010). Nylanderia fulva infests buildings and greenhouses. This ant can attack domestic animals, honeybee hives, and several crop plants; it can also displace native ant species (Hill et.al, 2013). It can aggregate in large numbers in electrical equipment and cause short circuits or clog switching mechanisms, resulting in equipment failure.

The Tawny crazy ant is a social insect usually found in large numbers that lives in large colonies and seem to be indistinguishable from each other. Males and workers are similar in size while queens are larger. Colonies contain many queens, workers and brood (larvae and pupae). Pupae are naked (without cocoons). Colonies periodically produce winged male and female forms called sexuals, alates or reproductives. Foraging activity begins in spring and worker populations increase dramatically in density by mid- summer. (Nestor, 2002)

Worldwide Distribution:

Nylanderia fulva is native to South America, specifically southern Brazil and northern Argentina along the border of Uruguay and Paraguay (Kumar et. al., 2015). It has established in Anguilla, Bermuda, Colombia, Cuba, Guadeloupe, Martinique, Panama, Puerto Rico and the U.S. Virgin Islands. (Hill et. al., 2013)

In the United States, it was first recognized as N. fulva near Houston, Texas in 2002, but this record is preceded by previous misidentifications as N. pubens in Florida. Currently, Nylanderia fulva has become established in the states of Texas, Louisiana, Mississippi, Alabama, Florida, and Georgia.

Official Control: Nylanderia fulva has not been listed as a harmful organism in any U.S. states or other nations (PCIT, 2018).

California Distribution:  Nylanderia fulva has never been found in the natural environment of California.

California Interceptions:  Nylanderia species were intercepted 107 times between July 2013 and January 2018 by CDFA through detection surveys, border stations, dog team inspections, and high-risk pest exclusion activities.

The risk Nylanderia fulva (tawny crazy ant) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Nylanderia fulva is omnivorous and its foraging trails widens  as the temperature rises to 20°C. Foraging activity begins in spring and worker density can increase to millions during July – August and the number of ants remain high throughout fall. Nests can occur in leaf litter, soil, rotten logs, under potted plants, under rocks and along underground electrical circuits (Sharma et al., 2014). California’s climate and habitat would be suitable for occurrence of nests and rapid increase in          populations. It receives a High (3) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California:

Score: 3

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Nylanderia fulva worker ants tend plant-feeding hemipterous insects such as aphids, scale insects, whiteflies, mealy bugs and others that excrete honeydew. Workers are also attracted to sweet parts of plants including nectaries, and damaged and over-ripe fruit. They also consume other insects and small vertebrates for protein (Nestor, 2002). These hosts can be found throughout California. It receives a Medium (2) in this category.

Evaluate the host range of the pest:

Score: 2

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Nylanderia fulva queens lay single, white, ovoid-shaped eggs that incubate for approximately 16 days. The larvae that emerge pass through three (workers) or four (males) instars and the larval stage lasts about 11 days. Workers carry pupae to the nest where they are piled into mounds. Adults emerge from pupae after 12 days. Nuptial flight activity has not been recorded until recently. New findings have confirmed that alate males fly throughout the year but females are produced only once a year (Wang, et al., 2016). Colonies spread by budding with breeding occurring at the periphery. The annual rate of spread by ground migration is about 20-30 m per month in industrial areas and about 207 m per year in rural landscapes (Nestor, 2002). Nylanderia fulva can be transported long distances by the movement of infested material including garbage, yard debris, compost, potted plants and bales of hay transported by truck, railroad and airplane. It receives a High (3) in this category.

Evaluate the natural and artificial dispersal potential of the pest:

Score: 3

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Nylanderia fulva, in large numbers, can become a nuisance and make human activities uncomfortable and difficult. Infestations can extend to sidewalks, buildings and gardens. These ants are capable of biting small livestock, causing them to die of asphyxia and can attack large animals around their eyes, nasal fossae and hooves. Their foraging and nesting behavior can cause short circuits in electrical equipment. Since this species feeds on the exudate of hemipteran insects, it can result in the disruption of biocontrol and cause losses from increased crop damage. This species has been reported to destroy honey bee hives in Texas by consuming brood, and then colonizing the hive (Harmon, 2009). It receives a High (3) in this category.

Evaluate the economic impact of the pest to California using the criteria below:

Economic Impact: A, B, D, F

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Nylanderia fulva is likely to reduce biodiversity of other animals, both invertebrates and vertebrates. Larger ant populations have forced ground and tree nesting birds and other small animals to move out of the area (LeBrun et. al, 2013). Masses of these ants covering the ground and trees can cause wildlife to move out of the area. Ecological impacts by fulva include reduction in arthropod diversity, particularly native ant species. This ant can undoubtedly impact ecosystems in its adventive range and has the potential to cause cascading ecological impacts (Wang et al., 2016). Large infestations may be difficult to control and would need professional pest control services to treat affected areas. It receives a High (3) in this category.

Evaluate the environmental impact of the pest on California using the criteria below:

Environmental Impact: A, B

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Score the pest for Environmental Impact:

Environmental Impact Score: 3

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Nylanderia fulva (tawny crazy ant): High (14)

Add up the total score and include it here:

-Low = 5-8 points

-Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Nylanderia fulva (tawny crazy ant) has never been found in the environment in California and receives a Not established (0) in this category.

Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included:

Score: 0

–Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: High (14)

Uncertainty:

Five species of Nylanderia are native to the southwestern United States including California. Nylanderia fulva has a potential to overlap with these native species. Since this species is currently established in the southeastern states mentioned above, any host material coming from those areas could potentially contain N. fulva. The presence of only a few workers in incoming samples can also make it difficult to identify Nylanderia to species level because males are needed to positively identify N. fulva.  Detection surveys in California would likely aid in the early detection of this invasive ant.

Conclusion and Rating Justification:

Nylanderia fulva has not been recorded in the environment of California and would likely have significant economic and environmental impacts if it were to enter the state.  An “A”-rating is justified.

References:

Harmon, K. 2009. Honeybees Face New Threat in Texas: “Crazy” ants. Accessed 1/25/18.  (http://www.scientificamerican.com/blog/post.cfm?id=honeybees-face-new-threat-in-texas-2009-08-07).

Hill, S.K., Baldwin, R.W., Pereira, R.M. &  Koehler, P.G., 2013. Tawny Crazy Ant. Publication # SP486D, University of Florida, Accessed 1/26/18 http://edis.ifas.ufl.edu/pdffiles/IN/IN107600.pdf.

Kumar, S., LeBrun, E.G., Stohlgren, T.J., Stabach, J.A.,McDonald, D.L., Oi, D.H. &  J.S. LaPolla. 2015. Evidence of niche shift and global invasion potential of the tawny crazy ant, Nylanderia fulva. Ecol. 5, 4628–4641

LeBrun, E. G., Abbott. & L. E. Gilbert. 2013. Imported crazy ant displaces imported fire ant, reduces and homogenizes grassland ant and arthropod assemblages. Biological Invasions 15: 2429-2442.

MacGown, J. A. & B. Layton. 2010. The invasive Rasberry crazy ant, Nylanderia sp. near pubens (Hymenoptera:  Formicidae), Midsouth Entomologist Vol 3: 1:  441- 47. Accessed1/26/18. http://midsouthentomologist.org.msstate.edu/Volume3/Vol3_1_html_files/vol3_1_008.htm

Nestor, P.R. 2002. Tawny (Rasberry) Crazy Ant. Center for Urban and Structural Entomology. Texas A & M Agrilife Extension. Accessed 1/25/18.  http://bugwoodcloud.org/resource/files/6305.pdf

Pest and Damage Record Database. Pest Prevention and Plant Health Services. CA Department of Food and Agriculture. Accessed 1/24/18. http://phpps.cdfa.ca.gov/user/frmLogon2.asp

Sharma, S, Warner, J and R.H. Scheffrahn, 2014. Featured Creatures. Tawny Crazy Ant. Nylanderia fulva. Entomology and Nematology Department, University of Florida. Accessed 1/25/18.  http://entnemdept.ufl.edu/creatures/urban/ants/tawny_crazy_ant.htm

USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Accessed 1/24/18. https://pcit.aphis.usda.gov/PExD/faces/PExDReport.jsp

Wang, Z., Moshman, L., Kraus, E.C., Wilson, B.E. Acharya N., and Diaz, R., 2016. A Review of the Tawny Crazy Ant, Nylanderia fulva, an Emergent Ant Invader in the Southern United States: Is Biological Control a Feasible Management Option? Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA; Accessed 1/24/18. www.mdpi.com/2075-4450/7/4/77/pdf

Author:

Raj Randhawa, 1220 ‘N’ Street, Room 221, Sacramento CA 95814, (916) 403-6617, plant.health[@]cdfa.ca.gov

Responsible Party:

Jason Leathers, 2800 Gateway Oaks, Sacramento CA 95833, (916) 654-1211, plant.health[@]cdfa.ca.gov

Comment Period:* CLOSED

4/12/18 – 5/27/18

*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

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♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.

Pest Rating: A  

Posted by ls 

A-Rated, Hymenoptera, Insects, Mites & Earthworms

Compact Carpenter Ant | Camponotus planatus

California Pest Rating  for
Compact Carpenter Ant | Camponotus planatus
Hymenoptera:  Formicidae
Pest Rating: A

 

PEST RATING PROFILE 

Initiating Event:

Camponotus planatus has been intercepted 34 times in 2018 during January and February at various CDFA border stations during inspection of vehicles entering CA. Recently, multiple live ants of this species have been intercepted at on a trailer entering Blyth inspection station (PDR # BL0P06743971). The trailer was carrying a load of bee colonies, originating from Florida. Camponotus planatus has temporary rating of “Q”.  A pest rating proposal is required to determine a permanent pest rating.

History & Status:

Background:  Camponotus planatus is a small polymorphic ant. It is primarily an arboreal species, but it is increasingly becoming a structural pest in Florida. These ants feed on drops of honey dew from exterior walls of structures, trees, shrubs, along sidewalks and through lawns. This ant species is a day-active ant; therefore, they are observed more than nocturnal carpenter ants. (University of Florida)

Camponotus planatus have colonies with a single queen. Queens start new colonies and care for the first larvae until they develop into workers. Workers in turn begin to forage for food and to care for the queen, new eggs and the larvae. Colonies continue to grow for 2-5 years. Newly winged reproductives, known as Alates, are observed from spring to fall. (University of Florida)

The most common habitats of Camponotus planatus include hollow twigs, empty spaces in trunks of trees, dead wood, old termite galleries and leaf axils of palm (Deyrup 1991)

Worldwide Distribution: Camponotus planatus is widely distributed in Cuba, and from Mexico to Columbia. In United State, it is well established in parts of Florida including Sarasota in Tempa, East Miami (Deyrup, 1991), Texas and Hawaii. These ants have also been reported in Fort Myers in Lee county, Coconut Groves areas in Dade county, Hillsborough ,Manatee, Monroe, Orange  and Sarasota counties areas in Miami, Florida (Warner and Scheffrahn, 2017).

Official Control: Camponotus has been named as a harmful organism in Namibia, the Republic of Korea, South Africa, and Taiwan (PCIT)

California Distribution:  Camponotus planatus has never been found in the natural environment of California.

California Interceptions:  Camponotus planatus was intercepted 28 times between January 2014 and October 22, 2017 by CDFA at various border station during inspection of vehicles entering California.

The risk Camponotus planatus (compact carpenter ant) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Camponotus planatus has been found in tropical moist forests, wet lowland forests and tropical rain forests of the world. This species commonly feeds on honey dew from structural walls with surface temperatures of up to 37-degree Celsius. (University of Florida). Many Camponotus species are found in foothill and mountain communities of California. (Pest of Homes, Structures, People and Pets, UCANR Publication). It receives a High (3) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California:

Score: 3

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Camponotus planatus live in hollow tree twigs, old termite galleries, dead wood, voids in tree trunks and leaf axil bases in palms. These habitats can be found throughout California. It receives a Medium (2) in this category.

Evaluate the host range of the pest:

Score: 2

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Camponotus planatus develops by complete metamorphosis by going through egg, larva, pupa in silk cocoon and adult stages. Single queen starts new colony of male, female and worker ants. This colony can continue to grow for 2-5 years. Once the colony is mature, it produces winged adults that go for mating flights between spring and fall. Colony size can be up to 10000 worker ants. Long distance spread of this species can be caused by movement of fire wood. It receives a High (3) in this category.

Evaluate the natural and artificial dispersal potential of the pest:

Score: 3

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Camponotus planatus has been found in a nursery in   Mississippi that specializes in palms (Arecaceae) and makes nests towards uppermost part of palms. There are nurseries in the south coast of California that produce and sell palm trees. The crop quality and value can be impacted if this species were to get establish in the state. Camponotus planatus may also be a significant predator of native ants and other arthropods. Camponotus planatus is not only likely to become a nuisance pest of exterior buildings but it can also enter the buildings through structural cracks and crevices. It has been reported to protect honeydew producing insects (MacGown 2014). It receives a High (3) in this category.

Evaluate the economic impact of the pest to California using the criteria below:

Economic Impact: A, D, E

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Camponotus planatus is reported to exert ecological pressure on native ants. In natural ecosystem, carpenter ants play an important role by decomposing wood back into soil (Harris & Berry, 1994). Since this species is mainly a pest of structures and wood, it could significantly impact cultural practices like trimming of tree branches close to structures, sealing of potential entry points, increasing ventilation to damp areas and storing firewood away from structures and off the ground. It receives a High (3) in this category.

Evaluate the environmental impact of the pest on California using the criteria below:

Environmental Impact: A, E

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Score the pest for Environmental Impact:

Environmental Impact Score: 3

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Camponotus planatus (compact carpenter ant): High (14)

Add up the total score and include it here:

-Low = 5-8 points

-Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Camponotus planatus (compact carpenter ant) has never been found in the environment and receives a Not established (0) in this category.

Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included:

Score: 0

–Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: High (14)

Uncertainty:

Camponotus planatus is being intercepted regularly at various border station of California. Even though it has not been found in the natural environment, it can likely be introduced from south eastern states especially Florida, Texas and Hawaii. Since various Camponotus species are found in California, it is possible that C. planatus may be present in some areas especially in palm growing nurseries in southern California.

Conclusion and Rating Justification:

Camponotus planatus has never been found in the environment of California and would likely to have significant economic and environmental impacts if it were to enter the state.  An “A”-rating is justified.

References:

Ant Wiki, Assessed 10/23/2017  http://www.antwiki.org/wiki/Camponotus_planatus

Ant Key ID Guide. Introduced ants. Camponotus planatus. Assessed 10/23/2017  http://antkey.org/en/taxa/camponotus-planatus

Ant Web: Assessed 10/24/2017  https://www.antweb.org/description.do?genus=camponotus&species=planatus&rank=species&countryName=Mexico

Deyrup MA. 1991. Exotic Ants of the Florida Keys (Hymenoptera: Formicidae). Proceedings of the 4th Symposium on the Natural History of the Bahamas. 21 pp.

Deyrup, M.  2003. An updated list of Florida ants (Hymenoptera: Formicidae). Florida Entomologist 86: 43-48.

Harris, Richard & Berry Jo. 1994. Invasive Ant Threat. Information Sheet Number 2: Camponotus Mayr. Biosecurity New Zealand. Assessed 10/25/2017  https://www.landcareresearch.co.nz/__data/assets/pdf_file/0015/51009/2.pdf

H. Klotz, Dept. of Entomology, UC Riverside; M. K. Rust, Dept. of Entomology, UC Riverside; and L. D. Hansen, Dept. of Life Sciences, Spokane Falls Community College.

Pest Notes: Carpenter Ants. UCANR Publication 7416, UC Statewide IPM Program, UC Davis. Assessed 10/25/2017  http://ipm.ucanr.edu/PMG/PESTNOTES/pn7416.html

–MacGown Joe, Camponotus planatus (Hymenoptera: Formicidae), an Exotic Carpenter Ant Found in Mississippi, Mississippi Entomological Museum, Mississippi State University, Mississippi State, MS, 39762, Assessed 10/25/2017  http://mississippientomologicalmuseum.org.msstate.edu/Researchtaxapages/Formicidaepages/ant.publications/Camponotus_planatus_MacGown2010.pdf

MacGwon, Joe. A. 2014. Ants (Formicidae) of the southeastern united states. Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University. Assessed 10/25/2017.

http://mississippientomologicalmuseum.org.msstate.edu/Researchtaxapages/Formicidaepages/genericpages/Camponotus_planatus.htm#.WfJLnE2WzL8

USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Assesses 10/24/2017 https://pcit.aphis.usda.gov/pcit/

Warner, John and Scheffrahn, Rudolph. 2017. Featured Creatures: Camponotus planatus. University of Florida, Entomology and Nematology. Assessed 10/24/2017 http://entomology.ifas.ufl.edu/creatures/urban/ants/c_planatus.htm

Author:

Raj Randhawa, 1220 ‘N’ Street, Room 221, Sacramento CA 95814, (916) 403-6617, plant.health[@]cdfa.ca.gov

Responsible Party:

Jason Leathers, 2800 Gateway Oaks, Sacramento CA 95833, (916) 654-1211, plant.health[@]cdfa.ca.gov

Comment Period:* CLOSED

4/11/18 – 5/26/18

*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

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♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.

Pest Rating: A

 

Posted by ls 

A-Rated, Acari, Insects, Mites & Earthworms

Peacock Mite | Tuckerella sp

California Pest Rating for
Peacock Mite | Tuckerella sp.
Acari: Tuckerellidae
Pest Rating: A

 

PEST RATING PROFILE

Initiating Event:

Tuckerella sp. (Peacock mite) was intercepted in June 2017 by San Joaquin county dog team on a shipment of Mango fruits (Magnifera indica) originating in Miami, Florida ( PDR# 570P6611570)  and again in July 2017 by Sacramento county dog team from a shipment of mamey sapote (Pouteria sapota) fruits originating in Puerto Rico (PDR# 570P06611782) . This species has temporary rating of “Q”.  A pest rating proposal is required to determine a permanent pest rating.

History & Status:

Background: Tuckerella spp. are significant herbivorous pests in the tropics on citrus fruit. They are called peacock mites because of the peacock tail of plumose posterior setae that trails out behind them. Their dorsal shields are covered with large, leaf like setae. These setae are swept over the body to deter predators (Walter 2009).

Tuckerellids are slow moving, typically bright red and occur in soil and in stems, leaves and fruit of plants. Described species of Tuckerella fall into two species groups that segregate ecologically. One group is found in association with grasses (perhaps feeding on roots) and the other on stems and fruits of woody plants. Some species of the latter group are pests of citrus (Walter 2009)

Worldwide Distribution: Tuckerella spp. have limited distribution worldwide. Half of the spp. are reported from eastern Asia. T. ornata (Tucker), T. pavoniformus (Ewing) and T. knorri Baker and Tuttle are originally described from South Africa, Hawaii and Thailand respectively and are each reported from several continents (Manual of Acarology 2009).

Official Control: Two Tuckerella sp. are considered harmful organisms. Tuckerella. flabellifera and T. japonica are reported as harmful organisms in the Republic of Korea and Japan respectively (PCIT 2016).

California Distribution: Tuckerella spp. have never been found in the natural environment of California.

California Interceptions: Tuckerella spp. have been intercepted five times between July, 2011 and July, 2017 by CDFA at various border stations during inspection of vehicles entering California.

The risk Tuckerella sp. (Peacock mite) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Tuckerella are mainly found in the tropics and have been reported occurring in soils and in association with underground plant parts. However, T. hypoterra has been collected from pasture soil in South Dakota and T. colegynis from foliage and debris in Nevada (Krantz 2009). Depending on the species, Tuckerella spp. might establish a widespread distribution in California and receives a High (3) in this category

Evaluate if the pest would have suitable hosts and climate to establish in California:

Score: 3

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Tuckerelilids are considered pests of ornamentals and fruit crops in the United States. Peacock mite cause damage to citrus, avocado, tea and other ornamental and fruit crops (Ochoa, 2010). These crops are widely cultivated in California. It receives a High (3) in this category

Evaluate the host range of the pest:

Score: 3

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Tuckerlilid mites have a high reproduction rate, several reproduction modes and short life cycles. Peacock mites have 5-7 pairs of caudal setae that help with their wind borne dispersal (The full wiki, 2010). Mites are very small and small populations are not easily detectable during visual inspection. This allows them to be rapidly transported long distance when infested plants or fresh plant material is moved. Peacock mite receives a High (3) in this category.

Evaluate the natural and artificial dispersal potential of the pest:

Score: 3

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Peacock mite was recorded in Central America as a pest of citrus plants and fruits but it has never been associated with serious damage to citrus. Tuckerella knorri has been reported as a serious pest of citrus in Costa Rica and is likely to reduce yields. It is reported to occur in association with the fungus Sphaceloma fawceti which is considered a causative agent of the cracking of citrus fruits (Vacante 2010). It receives a Medium (2) in this category.

Evaluate the economic impact of the pest to California using the criteria below:

Economic Impact: A, E

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 2

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Tuckerella are not likely to lower the biodiversity and disrupt natural communities. Since mites can be contaminants of stored grains and phytoparasites of several crops, its infestations could cause private treatment by homeowners. It receives a Medium (2) in this category.

Evaluate the environmental impact of the pest on California using the criteria below:

Environmental Impact: A, E

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered sp..

C. The pest could impact threatened or endangered sp. by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Score the pest for Environmental Impact:

Environmental Impact Score: 2

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Tuckerella sp. (peacock mite): High (13)

Add up the total score and include it here:

-Low = 5-8 points

-Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Tuckerella has never been found in the environment and receives a Not established (0) in this category.

Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included:

Score: 0

–Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: High (13)

Uncertainty:

Peacock mites have been intercepted a few times by CDFA for many years. Some Tuckerella spp. like T. pavoniformis do not cause economic damage to citrus but other sp. like T. knorri can damage citrus plants and fruits. Even though Tuckerella spp. have not been found in natural environment of California, they can resemble California native mites like citrus bud mite and Texas citrus mite. If Tuckerella spp. are introduced to California, they might have the potential to cause significant economic damage to citrus growing areas of the state. There have not been any formal surveys done to confirm the presence of Tuckerella spp. in California on crops like Citrus and avocado. Early surveys can confirm the presence of Tuckerella spp. in California.

Conclusion and Rating Justification:

Tuckerella sp. has never been found in the environment of California and might have significant economic and environmental impacts if it were to enter the state. An “A”-rating is justified.

References:

 Krantz G.W. 2009. A manual of Acarology, 3rd edition, pp 302

Ochoa R., Aguilar H., and Vargas C. 1994. Phytophagous mites in Central America: an illustrated guide

Ochoa, Ronald-Ron. 2010. Mite Systematics and Arthropod Diagnostics with Emphasis on Invasive sp.. USDA ARS Systematic Entomology Laboratory, Beltsville, MD  https://www.ars.usda.gov/research/project/?accnNo=420497 

Ochoa, Ronald. The genus Tuckerella in Costa Rica (Acari: Tuckerllidae). International Journal of Acarology. 14 (2): 205-207

The Full Wiki. 2010. Tuckerella Encyclopedia http://www.thefullwiki.org/Tuckerella

Vacante, Vincenzo. 2010. Review of the phytophagous mites collected on Citrus in the world. Acarologia 50 (2): 221-241.

Walter, David Evans; Proctor, Heather (2013). Mites: Ecology, Evolution & Behavior. Springer Science & Business Media. p. 292. ISBN 978-94-007-7164-2.

Author:

Raj Randhawa, 1220 ‘N’ Street, Room 221, Sacramento CA 95814, (916) 403-6617, plant.health[@]cdfa.ca.gov

Responsible Party:

Jason Leathers, 2800 Gateway Oaks, Sacramento CA 95833, (916) 654-1211, plant.health[@]cdfa.ca.gov

Comment Period:*CLOSED

4/11/18 – 5/26/18

*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

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♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.

Pest Rating: A

 

Posted by ls 

A-Rated, Hemiptera, Insects, Mites & Earthworms

Plant Bug | Rubrocuneocoris calvertae

California Pest Rating  for
Plant Bug | Rubrocuneocoris calvertae Henry
Hemiptera: Miridae
Pest Rating: A

PEST RATING PROFILE

Initiating Event:

Rubrocuneocoris calvertae was reported to be established on Hawaii and Oahu islands, Hawaii (Henry, 2017; J. Matsunaga, pers. comm.).  It is currently Q-rated, and a permanent pest rating proposal is required to support an official pest rating.

History & Status:

Background:  Rubrocuneocoris calvertae is a small plant bug (approximately 2.5 millimeters in length) that is dull brown in color except for distinctive red markings on the posterior portion of the forewings (a character shared with other members of the genus).  This species is only known from Hawaii, but it is presumed to have been introduced from somewhere in Asia or the Pacific, because the other species in the genus are native to these areas.  In Hawaii, R. calvertae is reported to feed on Macaranga tanarius (Euphorbiaceae) and Pipturus sp. (Urticaceae) (Henry, 2017; J. Matsunaga, pers. comm.), but no information is available on the extent of damage inflicted on these plants by this bug.  Very little information was found on the biology of this genus.  Most collections of Rubrocuneocoris appear to have been made with light or malaise traps, which provides little biological information.

Worldwide Distribution:  Rubrocuneocoris calvertae is only known from Hawaii (Hawaii and Oahu islands), and it was presumably introduced there from an unknown location in east Asia or the Pacific (Henry, 2017; J. Matsunaga, pers. comm.).

Official Control: Rubrocuneocoris calvertae is not known to be under official control anywhere.

California Distribution:  Rubrocuneocoris calvertae is not known to be present in California (Symbiota Collections of Arthropods Network).

California Interceptions:  Rubrocuneocoris calvertae has not been intercepted in California.

The risk Rubrocuneocoris calvertae would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Rubrocuneocoris calvertae has been reported to feed on plants in the families Euphorbiaceae and Urticaceae. There are plants in these families present throughout California.  This insect is only known to be present in Hawaii, although it is presumed to be native to somewhere in east Asia or the Pacific.  At least one species in the genus Rubrocuneocoris occurs in the Primorye region of the Russian Federation, which suggests it may be tolerant of a more temperate climate (Vinokurov et al., 1988).  Therefore, even though it is likely that calvertae originated in a tropical or subtropical area and is limited to such climates, it is also possible that this species is native to an area with a temperate climate, and thus could survive in much of California.  Therefore, R. calvertae receives a High (3) in this category.

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: This species has been reported to feed on two families of plants, the Euphorbiaceae and Urticaceae. Its native distribution is unknown, but this species may feed on other plants there.  The unknown feeding habits in the (also unknown) native range are considered here.  Therefore, calvertae receives a Medium (2) in this category.

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Rubrocuneocoris calvertae presumably flies, because other species in the genus are caught at light traps (Schuh, 1984).  Therefore, it receives a Medium (2) in this category.

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: This species feeds on plants.  It is not known to be present in California, and it is possible that it has a very limited distribution and may not have been exposed to some economically-significant plants that are present in California.  Therefore, even though there is no evidence that calvertae is a pest elsewhere, there is still the possibility that it could become a pest in California if it became established here.  If it became a pest in California, it could lower crop yield and increase crop production costs, for example, through increased pesticide use.  Therefore, it receives a Medium (2) in this category.

Economic Impact: A, B

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

The pest could trigger the loss of markets (includes quarantines).

The pest could negatively change normal cultural practices.

The pest can vector, or is vectored, by another pestiferous organism.

The organism is injurious or poisonous to agriculturally important animals.

The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 2

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: As explained above, under Economic Impacts, there is the possibility that calvertae could become a pest if it was established in California. This could trigger treatment programs, for example, in agriculture or ornamental plantings.  There is a rare Euphorbia species in California, E. hooveri, which could be attacked by R. calvertae if it became established in California.  Therefore, R. calvertae receives a High (3) in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: B, D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 3

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Rubrocuneocoris calvertae: Medium (12)

Add up the total score and include it here.

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Rubrocuneocoris calvertae is not known to be present in California.  It receives a Not established (0) in this category.

–Not established (0) Pest never detected in California, or known only from incursions.

–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

–High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (12)

Uncertainty:

The full extent (including native range) of the distribution of R. calvertae are presumably not known.  This means that the climatic tolerances and feeding habits of this insect are also unknown, which makes it challenging to determine its potential for impact in California.  No information was found suggesting that any species in the genus Rubrocuneocoris is a pest.  This suggests that the genus may have a low potential for economic or environmental impact.

Conclusion and Rating Justification:

Rubrocuneocoris calvertae is only known from Hawaii, but it is presumed to be native somewhere in Asia or the Pacific.  It is possible that it could have economic and environmental impacts if it became established in California.  For these reasons, an “A” rating is justified.

References:

Henry, T.  2017.  A new species of the plant bug genus Rubrocuneocoris Schuh (Heteroptera: Miridae: Phylinae) from Hawaii.  Proceedings of the Entomological Society of Washington.  119(1): 63-69.

Lin, C-S.  2006.  Genus Rubrocuneocoris Schuh (Hemiptera: Miridae) of Taiwan.  Formosan Entomologist.  26: 295-302.

Schuh, R.T.  1984.  Revision of the Phylinae (Hemiptera, Miridae) of the Indo-Pacific.  Bulletin of the American Museum of Natural History.  177: 1-476.

Symbiota Collections of Arthropods Network.  Accessed November 20, 2017. http://scan1.acis.ufl.edu

Vinokurov, N.N., Golub, V.B., Kanyukova, E.V., Kerzhner, I.M., and G.P. Tshernova.  1988.  Volume II: Homoptera and Heteroptera.  In (P.A. Lehr, ed.) Keys to the Insects of the Far East of Russia.  Nauka Publishing House, Leningrad.  972 pp.

Author:

Kyle Beucke, 1220 N Street, Room 221, Sacramento, CA, 95814, 916-403-6741, plant.health[@]cdfa.ca.gov

Responsible Party:

Jason Leathers, 2800 Gateway Oaks, Sacramento CA 95833, (916) 654-1211, plant.health[@]cdfa.ca.gov

Comment Period:* CLOSED

4/10/18 – 5/25/18

*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

Violates agency regulations prohibiting workplace violence, including threats.

♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.

Pest Rating: A

Posted by ls 

A-Rated, Hemiptera, Insects, Mites & Earthworms

Stink Bug | Kalkadoona pallida

California Pest Rating  for
Stink Bug | Kalkadoona pallida (Van Duzee)
Hemiptera: Pentatomidae
Pest Rating: A

PEST RATING PROFILE

Initiating Event:

Six adult specimens of K. pallida were collected in a natural area reserve on Oahu Island, Hawaii, on May 26, 2016 (J. Matsunaga, pers. comm.).  This apparently represents the first detection of the species in the United States.

History & Status:

Background: Kalkadoona pallida is a pale brownish-yellow stink bug that measures 7-8 mm in length (Van Duzee, 1905).  This bug lives in desert sand dunes in Australia, where it has been recorded feeding on plants in the genera Dodonaea (Sapindaceae) and Enchylaena (Amaranthaceae) (Atlas of Living Australia; Cassis & Gross, 2002).  The specimens recently (2016) collected in Hawaii were found feeding on Atriplex suberecta (sprawling saltbush) (Amaranthaceae) (J. Matsunaga, pers. comm.).

Worldwide Distribution: Kalkadoona pallida is native to southern Australia.  It was recently reported in a natural area on Oahu Island, Hawaii, United States, where it was presumably introduced.

Official Control: Kalkadoona pallida is not known to be under official control anywhere.

California Distribution:  Kalkadoona pallida is not known to occur in California (Symbiota Collections of Arthropods Network).

California Interceptions: This species is not known to have been intercepted in California.

The risk Kalkadoona pallida would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: The area of Australia in which Kalkadoona pallida occurs has a semi-arid to arid climate. There are large areas in California that have a similar climate.  In addition, pallida is established on Oahu Island, Hawaii, which suggests that this species has a relatively broad climatic tolerance.  Therefore, Kalkadoona pallida receives a High (3) in this category.

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Kalkadoona pallida is known to feed on three species of plant, in three genera. Therefore, pallida receives a Medium (2) in this category.

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Kalkadoona pallida is capable of flight, as at least some of the collecting records from Australia indicate specimens were captured in flight or were attracted to light. Reproductive potential is unknown for this species.  Therefore, pallida receives a Medium (2) in this category.

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Within the plant families that Kalkadoona pallida has been recorded feeding upon, there are some crops (spinach and beets, in the Amaranthaceae) and ornamental plants (in the Scrophulariaceae). However, this insect prefers arid or semi-arid conditions, and there do not appear to be any reports of it being a pest in Australia, which has a similar climate to California.  In Hawaii, it feeds on an introduced weed growing near the shore and is not known to be a pest there.  For these reasons, it seems unlikely that Kalkadoona pallida could significantly impact agriculture in California.  Therefore, it receives a Low (1) in this category.

Economic Impact:

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 1

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: The reported host plants of this species in Australia belong to the families Amaranthaceae and Scrophulariaceae. Also within these families are some rare California plants, including the Federally-endangered Suaeda californica Watson (California seablite), which is limited to the California coast, the rare Amaranthus watsonii Standley (Watson’s amaranth), which occurs in creosote bush scrub in southern California, a number of Atriplex species (saltbushes, etc.), and the rare Scrophularia villosa Pennell (Santa Catalina figwort).  It is possible that, if K. pallida was introduced to California, it could feed on and threaten these species.  The Atriplex species are perhaps most at risk because K. pallida is known to feed on A. suberecta in Hawaii.  Pentatomids are known to transmit plant diseases.  If K. pallida can transmit such diseases, this would pose an additional risk to California native plants.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: B

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Score the pest for Environmental Impact. Score:

Environmental Impact Score: 2

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Kalkadoona pallida: Medium (10)

Add up the total score and include it here.

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Kalkadoona pallida is not known to occur in California.  It receives a Not established (0) in this category.

–Not established (0) Pest never detected in California, or known only from incursions.

–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

–High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (10)

Uncertainty:

This species is not known to be a pest in Hawaii, which is the only locality to which this species is known to have been introduced.  However, there are native species of Atriplex present in California, and these native species could be more heavily impacted.  It is also possible that this species could feed on a much broader range of hosts if it became established in California.

Conclusion and Rating Justification:

Kalkadoona pallida is a phytophagous insect that is likely capable of becoming established in California.  If it did so, it is unlikely to have an economic impact, but it could attack multiple species of rare plants.  The potential for environmental damage, and the fact that this species is not yet present in the state, justify an “A” rating.

References:

Atlas of Living Australia.  Accessed March 2, 2018.  https://www.ala.org.au/

Calflora.  Accessed March 2, 2018. http://www.calflora.org

Cassis, G. & Gross, G.F.  2002.  Entomological Catalogue of Australia.  CSIRO Publishing.  737 pp.

Symbiota Collections of Arthropods Network.  Accessed March 2, 2018. http://scan1.acis.ufl.edu

Van Duzee, E.P.  1905.  Notes on Australian Pentatomidae, with descriptions of a few new species.  Bulletin of the American Museum of Natural History.  21: 187-214.

Author:

Kyle Beucke, 1220 N Street, Room 221, Sacramento, CA, 95814, 916-403-6741, plant.health[@]cdfa.ca.gov

Responsible Party:

Jason Leathers, 2800 Gateway Oaks, Sacramento CA 95833, (916) 654-1211, plant.health[@]cdfa.ca.gov

Comment Period:* CLOSED

4/10/18 – 5/25/18

*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

Violates agency regulations prohibiting workplace violence, including threats.

♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.

Pest Rating: A

 

Posted by ls 

A-Rated, Hemiptera, Insects, Mites & Earthworms

False Trochanter Mealybug | Pseudococcus dolichomelos

California Pest Rating  for
False Trochanter Mealybug | Pseudococcus dolichomelos Gimpel and Miller
Hemiptera: Pseudococcidae
Pest Rating: A

 

PEST RATING PROFILE

Initiating Event:

Pseudococcus dolichomelos is currently Q-rated.  A permanent pest rating proposal is required to support an official pest rating.

History & Status:

Background:  This mealybug is found underground on the roots and crown of its host plants (Gimpel and Miller, 1996).  It presumably feeds on roots.  It has been associated with plants in at least 12 families: Amaryllidaceae, Asteraceae, Euphorbiaceae, Fabaceae, Hypericaceae, Onagraceae, Poaceae, Polygonaceae, Rosaceae, Solanaceae, Urticaceae, and Zingiberaceae (García Morales et al., 2016).  The biology of this recently-described (1996) species is poorly known.

Worldwide Distribution:  Pseudococcus dolichomelos occurs in the eastern United States (Florida, Louisiana, Maryland, Michigan, New York, North Carolina, South Carolina, Texas, Utah, Washington, D.C., and West Virginia) and Hawaii (García Morales et al., 2016; Gimpel and Miller, 1996; von Ellenrieder and Watson, 2016).

Official Control: Pseudococcus dolichomelos does not appear to be under official control anywhere.

California Distribution:  Pseudococcus dolichomelos is not known to occur in California (Symbiota Collections of Arthropods Network).

California Interceptions:  Pseudococcus dolichomelos has been intercepted in California associated with cut flowers of Alpinia purpurata, Oncidium sp., and Zingiber sp. from Hawaii (PDR # 1367825, 1367535, 070P06137999, and 100P06282530), peaches from Utah (PDR # TR0P06024371), and primrose plants from Florida (PDR # 370P06678226).

The risk Pseudococcus dolichomelos would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Pseudococcus dolichomelos occurs over a wide portion of the United States, including areas with temperate (e.g., Michigan) as well as tropical/subtropical (e.g., Hawaii, south Texas) climates. This suggests that this species is capable of becoming established over a wide portion of California. It has been associated with a wide variety of plants in 12 families, so it is not expected to be limited by distribution of potential host plants.  Therefore, Pseudococcus dolichomelos receives a High (3) in this category.

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Pseudococcus dolichomelos has been associated with, and presumably feeds on at least 12 families of plants. Therefore, it receives a High (3) in this category.

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Pseudococcus dolichomelos has been intercepted multiple times on cut flowers and other commodities, so it is evidently capable of being spread artificially on infested plants.  Therefore, it receives a Medium (2) in this category.

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Root-feeding mealybugs include species that are pests of food and ornamental plants.  However, dolichomelos is not known to be an economic pest anywhere it is known to occur, even though it occurs over a wide area.  Therefore, it receives a Low (1) in this category.

Economic Impact:

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 1

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Root-feeding mealybugs have the potential to impact the health of plants, as demonstrated by the fact that some are economically-significant pests. If Psuedococcus dolichomelos became established in California, it would encounter species of native plants, including many rare ones, that it has not previously been exposed to.  It is possible that it could have an impact of some of these plants.  Therefore, it receives a Medium (2) in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: A

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 2

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Pseudococcus dolichomelos: Medium (11)

Add up the total score and include it here.

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Pseudococcus dolichomelos is not known to occur in California.  It receives a Not established (0) in this category.

–Not established (0) Pest never detected in California, or known only from incursions.

–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

–High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (11)

Uncertainty:

The most important uncertainty regarding this species is its ability to significantly impact the health of plants; this has not been shown to be the case anywhere it currently occurs.

Conclusion and Rating Justification:

Pseudococcus dolichomelos is a root-feeding mealybug with a broad host range.  It is not known to occur in California, but it is likely capable of becoming established over a large portion of the state.  If this was to occur, it is not likely to become an economic pest, but there is a chance that it could impact the environment.  For these reasons, an “A” rating is justified.

References:

García Morales, M., Denno, B.D., Miller, D.R., Miller, G.L., Ben-Dov, Y., and Hardy, N.B. 2016. ScaleNet: A literature-based model of scale insect biology and systematics.  Accessed November 7, 2017.  http://scalenet.info.

Gimpel, W. F. and Miller, D.R. 1996. Systematic analysis of the mealybugs in the Pseudococcus maritimus complex (Homoptera: Pseudococcidae). In (B.K. Gupta, ed.) Contributions on Entomology, International (pp. 38-42).  Associated Publishers.  Gainesville, Florida.  163 pp.

Symbiota Collections of Arthropods Network.  Accessed March 7, 2018. http://scan1.acis.ufl.edu

von Ellenrieder, N., and Watson, G.  2016.  A new mealybug in the genus Pseudococcus Westwood (Hemiptera: Coccomorpha: Pseudococcidae) from North America, with a key to species of Pseudococcus from the New World.  Zootaxa.  4105: 65-87.

Author:

Kyle Beucke, 1220 N Street, Room 221, Sacramento, CA, 95814, 916-403-6741, plant.health[@]cdfa.ca.gov

Responsible Party:

Jason Leathers, 2800 Gateway Oaks, Sacramento CA 95833, (916) 654-1211, plant.health[@]cdfa.ca.gov

Comment Period:* CLOSED

4/10/18 – 5/25/18

*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

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♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.

Pest Rating: A

Posted by ls 

A-Rated, Coleoptera, Insects, Mites & Earthworms

Dwarf Siberian pine beetle | Dryocoetes pini

California Pest Rating  for
Dwarf Siberian Pine Beetle | Dryocoetes pini
Coleoptera: Curculionidae: Scolytinae
Pest Rating: A

 

PEST RATING PROFILE

Initiating Event:

Dryocoetes pini is currently Q-rated.  A permanent pest rating proposal is required to support an official pest rating.

History & Status:

Background: This bark beetle measures approximately 2.5 mm in length.  Adults tunnel through the phloem (inner bark), where eggs are laid.  The larvae feed on the phloem.  This species has been reported to feed on pine (Pinus spp.), larch (Larix spp.), fir (Abies spp.), and spruce (Picea spp.) (European and Mediterranean Plant Protection Organization; Niijima, 1909).  The beetle is apparently not known as a significant pest in its native range (European and Mediterranean Plant Protection Organization).  Dryocoetes species are usually considered “secondary pests” and only attack dead, injured, or otherwise compromised host trees (Vega & Hofstetter, 2014).  At least one species, Dryocoetes confusus Swaine, is a serious pest of fir trees; it is apparently the most destructive member of the genus in North America (CABI,  2017; Hansen, 1996; Vega & Hofstetter, 2014).  The pathogenic fungus Grosmannia dryocoetis is associated with D. confuses (Vega & Hofstetter, 2014).  Similar fungi may also be associated with other Dryocoetes species, including D. pini.

Worldwide Distribution: Dryocoetes pini occurs in the Russian Far East, China, South Korea, and Japan (European and Mediterranean Plant Protection Organization; Park, 2016; Shiraki, 1952).  The species is not known to be present in North America.

Official Control: This species is not known to be under official control anywhere.

California Distribution: This species does not appear to be present in California (Symbiota Collections of Arthropods Network).

California Interceptions: This species is not known to have been intercepted in California.

The risk Dryocoetes pini would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: This species appears to occur primarily in areas with a temperate climate. It is possible that it could thrive in a large portion of California if it was introduced.  The tree genera that this species is known to feed upon occur throughout California.  Therefore, Dryocoetes pini receives a High (3) in this category.

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: As stated above, Dryocoetes pini has been reported from several coniferous genera. Therefore, pini receives a Medium (2) in this category.

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Dryocoetes pini is presumably capable of flight. Movement of wood (especially firewood) is a likely pathway for the human-aided dispersal of this species if it was to be introduced.  Reproductive potential is unknown for this species.  Therefore, pini receives a Medium (2) in this category.

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Dryocoetes pini has been reported to be associated with several genera of conifers, including Pinus.  There is a possibility that, if this species was to be introduced to California, it could have a different impact than what is observed in its native range, including killing trees, which could reduce yield of timber.  Significant infestations also have the potential to impact the recreational value of forests.  Therefore, it receives a Low (1) in this category.

Economic Impact:  A

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 1

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Major outbreaks of bark beetles have the potential to kill large numbers of trees, which can have long-lasting impacts. Such impacts could include changes in forest composition, destabilization of soil, and even fire dynamics (Jenkins et al., 2008).  There are rare or threatened conifers in California that could be impacted by the introduction of pini.  Therefore, it receives a High (3) in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: A, B

 A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

 B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 3

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Dryocoetes pini: Medium (11)

Add up the total score and include it here.

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Dryocoetes pini is not known to occur in California.  It receives a Not established (0) in this category.

–Not established (0) Pest never detected in California, or known only from incursions.

–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

–High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (11)

Uncertainty:

There is little information available on this species, so it was necessary to draw upon information regarding other species in the genus as well as other bark beetle genera.  There are also no examples of introductions involving this species, so assessment of the impacts of this species requires speculation.

Conclusion and Rating Justification:

Bark beetles can have significant impacts on forests.  One native species in the genus Dryocoetes, D. confusus, is an important pest in western forests.  Even though there is little information on the biology of D. pini, it seems justifiable to use caution and assign it an “A” rating.

References:

CABI.  2017.  Invasive Species Compendium. Wallingford, UK: CAB International. www.cabi.org/isc

European and Mediterranean Plant Protection Organization.  Forest pests on the territories of the former USSR.

https://www.eppo.int/QUARANTINE/special_topics/forestry_project/EPPOforestry_project.pdf

Hansen, E.M.  1996.  Western balsam bark beetle, Dryocoetes confusus Swaine, flight periodicity in northern Utah.  Great Basin Naturalist.  56(4): 348-359.

Jenkins, M.J., Hebertson, E., Page, W., & Jorgensen, C.A.  2008.  Bark beetles, fuels, fires and implications for forest management in the Intermountain West.  Forest Ecology and Management.  254: 16-34.

Niijima, Y.  1909.  Die Scolytiden Hokkaidos unter Berücksichtigung ihrer Bedeutung für Forstschäden.  The Journal of the College of Agriculture, Tohoku Imperial University.  3: 109-179.

Park, S.  2016.  Taxonomic review of Scolytinae and Platypodinae (Coleoptera: Curculionidae) in Korea.  Ph.D. thesis.  Seoul National University.

Shiraki, T.  1952.  Catalogue of injurious insects in Japan.  Preliminary Study Number 71.  General Headquarters, Supreme Commander for the Allied Forces, Economic and Scientific Section, Natural Resources Division.  133 pp.

Symbiota Collections of Arthropods Network.  Accessed March 2, 2018. http://scan1.acis.ufl.edu

Vega, F.E. & Hofstetter, R.W.  2014.  Bark beetles: Biology and ecology of native and invasive species.  Academic Press.  640 pp.

Author:

Kyle Beucke, 1220 N Street, Room 221, Sacramento, CA, 95814, 916-403-6741, plant.health[@]cdfa.ca.gov

Responsible Party:

Jason Leathers, 2800 Gateway Oaks, Sacramento CA 95833, (916) 654-1211, plant.health[@]cdfa.ca.gov

Comment Period:* CLOSED

4/9/18 – 5/24/18

*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

Violates agency regulations prohibiting workplace violence, including threats.

♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.

Pest Rating: A

 

Posted by ls 

A-Rated, Weeds

Alligatorweed | Alternanthera philoxeroides

California Pest Rating for
white flower with green leaves
Alligatorweed | Alternanthera philoxeroides
Family:  Amaranthaceae
Pest Rating: A | Proposed Seed Rating: R
PEST RATING PROFILE
Initiating Event:

There was a recent find of alligatorweed in Solano County; this is the first detection in northern California in many years.

History & Status:

Background: Alligatorweed is a perennial herb with horizontal to ascending stems to 1 m long, rooting at the nodes. The flowers are small and borne in small heads with white floral bracts. Like many aquatic emergent, it has distinctive submerged and emersed forms. The submerged form has hollow, floating, emergent and submerged stems. Terrestrial plants have solid stems. Typically, plants grow rooted in soil in shallow water and form dense, interwoven floating mats that extend over the surface of deeper water. Mats can become quite dense and nearly impenetrable. The floating mats can break away and follow currents to colonize new sites. Mats disrupt the natural ecology of a site by reducing light penetration and crowding out native species. Serious infestations can create anoxic, disease-promoting, and mosquito-breeding conditions.

Worldwide Distribution: This weed is found in wet, disturbed areas. It is also a weed of rice and sugar cane fields in tropical and subtropical regions. Native to southern Asia, alligatorweed is now found in tropical and subtropical regions around the world. It is considered an invasive species in Australia, China, New Zealand, and Thailand. Alligatorweed has been introduced throughout the southeastern United States from Virginia to Texas.

Official Control: Alligatorweed has had a CDFA rating of A as a pest in California for decades. The population in Los Angeles County has been managed intermittently over the years by the county, but it still persists.  It has official status as a weed in Alabama, Arizona, Arkansas, California, Florida, South Carolina, and Texas.

California Distribution:  Alligatorweed occurs in several southern California counties. It also has been detected in Contra Costa and Kings Counties, where it is eradicated. There was a recent find of 2 colonies in southern Solano County.

California Interceptions: Alligatorweed has been sent to CDFA by land managers.

The risk Alternanthera philoxeroides (alligatorweed) poses to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Risk is Medium (2), as the plant occurs in wetlands such as the Delta and creeks and rivers, as well as irrigation canals and watering ponds. These habitats are limited but widely distributed in California.

Evaluate if the pest would have suitable hosts and climate to establish in California:

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Most plants do not require any one host, but grow wherever ecological conditions are favorable. It receives a High (3) in this category.

Evaluate the host range of the pest.

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Risk is Medium (2). Alligatorweed can spread rapidly via water movement and on boats and equipment as stem fragments. It is also grown as an aquarium plant and occasionally discarded into waterways. Seeds evidently are not produced in the United States.

Evaluate the natural and artificial dispersal potential of the pest.

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Risk is High (3), as the plant can lower crop yields in rice fields, trigger state or international quarantines, and force changes in cultural practices by blocking canals. It has spread widely in the southeast, and has proven difficult to eradicate both there and in California. Its mats can improve habitat for mosquito larvae, leading to larger mosquito populations.

Evaluate the economic impact of the pest to California using the criteria below.

Economic Impact: A, C, D, E, G

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Risk is High (3) as alligatorweed could further invade the water systems of California, disrupt natural wetland communities and potentially lower biodiversity by invading wetlands. The dense growth impedes water movement, blocks the growth of native plants, and reduces available habitat for water birds and fish. Its invasion in the Delta and its tributaries could degrade habitat of rare species such as Mason’s lilaeopsis (Lilaeopsis masonii), Sacramento River Chinook salmon (Oncorhynchus tshawytscha),  and Giant garter snake (Thamnophis gigas).  Its presence would trigger additional control measures.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: A, C, D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact: Score: 3

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Alternanthera philoxeroides (alligatorweed) : High (13)

-Low = 5-8 points

-Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Alligatorweed currently is known from 3-4 populations in northern and southern California. It receives a Medium (-2) in this category.

Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included:

Score: -2

-Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (11)

Uncertainty:

Uncertainty is low, as alligatorweed has established in wetlands in California and other states. There is some uncertainty as to the actual distribution of this plant in California, as, like some other aquatic weeds, it is likely to be overlooked.

Conclusion and Rating Justification:

Conclusions of the harm(s) associated with this pest to California using all of the evidence presented above:

Proposed Rating: Despite its limited ability to disperse between watersheds, this is a potentially significant weed in California of both natural wetlands and irrigation canals. Because of its potential economic impacts, it deserves an A rating, as it has proven tenacious and is actively spreading.

References:

Baldwin, B. G., D. H. Goldman, D. J. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken, editors. 2012. The Jepson manual: vascular plants of California, second edition. University of California Press, Berkeley.

Consortium of California Herbaria. Accessed 10/3/2017:  ucjeps.berkeley.edu/consortium/

Florida Dept of Agriculture Weed of the Month: Alternanthera sessilis. Accessed 10/3/2017: http://www.freshfromflorida.com/Divisions-Offices/Plant-Industry/Plant-Industry-Publications/Weed-of-the-Month/April-2011-Alternanthera-Sessilis

Invasive Plant Atlas of the Mid-South. alligatorweed. Accessed 10/3/2017:    https://www.gri.msstate.edu/ipams/species.php?CName=Alligatorweed

Responsible Party:

Dean G. Kelch, Primary Botanist; California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6650. plant.health[@]cdfa.ca.gov.

*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

Pest Rating: A | Proposed Seed Rating: R

Posted by ls

A-Rated, Ratings, Vertebrate Pests

Nutria | Myocastor coypus

California Pest Rating for
Nutria  |  Myocastor coypus
Pest Rating: A
PEST RATING PROFILE
Initiating Event

On March 30, 2017 a suspected Nutria (Myocastor coypus) was turned in to California Department of Fish and Wildlife staff in Merced County. It was confirmed by the local Department of Fish and Wildlife Services trapper.  The animal was found living in a managed wetland (duck hunting club) adjacent to the Grasslands Ecological Area in Merced County.

History & Status

Background: 

Nutria are large aquatic rodents that may easily be confused with the even larger North American Beaver (Castor Canadensis). Their long rat-like tail is the primary distinguishing characteristic when compared to the large paddle shaped tail of the beaver. Nutria are herbivores that may consume up to 25% of their body-weight per day, in addition they are wasteful feeders focusing on roots and tubers while discarding up to 90% of the plant matter they harvest. They may impact crops and landscape plantings in areas adjacent to water ways, damage water conveyance and storage structures, undermine roads and vector parasites and diseases to humans and livestock. Nutria are primarily nocturnal, though lack of predatory pressure or the influence of human feeding may cause an increase in daytime activity. Nutria are prolific breeders, females may have 2-3 liters per year with an average of 4-5 offspring per liter. Young become sexually active between four and six months of age. Nutria nest in dense vegetation and construct burrows for protection from cold temperatures. Burrows can range from 6-45 meters in length. Nutria have been found to cause significant damage to wetland and riparian habitats and are considered agricultural pests in many parts of the world. In the early 1900’s they were purposefully introduced in many parts of the world to supplement the trapping of furbearing animals for the fur trade. In nature, their populations are primarily limited by harsh winters, commercial trapping and large predators such as alligators or large snakes. Nutria have successfully established in brackish estuarine waters around the United States, however they are not capable of natural immigration in to California with its mountains, deserts and coastline borders.

map for predicted suitable habitat
Figure 1. Geographical extent of predicted suitable nutria habitat (based on 2003 – 2007 mechanistic model) in the contiguous United States compared to the status of nutria populations by state. (Sheffels 2013)

Worldwide Distribution: 

Native to South America. Nutria are a common invasive species in the Southeastern United States. Blamed for significant impacts and loss of wetlands in the Mississippi Delta as well as the Chesapeake Bay. They are widespread in the Pacific Northwest, including Oregon, Washington and Southern British Columbia. Nutria have been successfully introduced and established in every continent other than Australia and Antarctica (Chesapeake Bay Nutria Eradication Project 2016).

Official Control:

A bounty system has been used in the past in Louisiana. During the 2009-2010 trapping season the state of Louisiana paid a $5 per animal bounty on 445,963 Nutria harvested for a total of $2,229,815 (Coastwide Nutria Control Program).

When necessary USDA – Wildlife Services will control localized populations of Nutria.  In 2002 an eradication program was initiated in the state of Maryland. As of 2016 all known populations had been removed from the Delmarva Peninsula of the Chesapeake Bay in Maryland. Surveillance is currently ongoing to verify eradication (Chesapeake Bay Nutria Eradication Project 2016).

Washington State requires any trapped Nutria to be immediately euthanized and prohibits their movement (Washington Invasive Species Council 2016).

Nutria are Considered an agricultural pest in China. Nutria eradication is underway in Japan. They are known to be responsible for damage to fish ponds in Israel. Nutria are considered a pest in Western Europe but a valuable resource in Eastern Europe where fur has higher value. England initiated a trapping eradication in 1981 and declared eradication in 1989. There are numerous Nutria eradication programs in France. They are considered a pest in Germany due to damage to dams. Nutria are also considered a pest of rice production in Italy. (Carter and Leonard 2002)

California Distribution:

There are historical reports of Nutria from Elizabeth Lake, Stanislaus River and Los Angeles County. The first introduction to the United States occurred at Elizabeth Lake California in 1899 which failed due to breeding failures. The California Department of Food and Agriculture conducted an eradication program for a feral population of Nutria from the Stanislaus River during the 1960’s. Eradication was achieved by 1978 (National Wetlands Research Center 2015).

Recent modeling of Nutria distribution and climate change predict that California is highly suitable for Nutria establishment and spread. The mountainous terrain and disconnected hydrological units are the only barrier between Northern California and the Nutria infested waterways of Southern Oregon (Jarnevich et al. 2017).

California Interceptions:

One adult Nutria was trapped in a managed wetland (duck hunting club) adjacent to the Grasslands Ecological Area in Merced County. There are anecdotal reports of additional Nutria sightings from the duck club caretaker.

Consequences of Introduction

The risk Nutria would pose to California is evaluated below.

Problems associated with high Nutria populations fall into several categories: destruction of marsh habitat, destruction of water control structures such as dykes and levees, destruction of agricultural crops, and the fact that the animals can serve as repositories of a variety of diseases.

1) Climate/Host Interaction: Evaluate if the pest would have suitable hosts and climate to establish in California. Score: 3

Low (1) Not likely to establish in California; or likely to establish in very limited areas.

Medium (2) may be able to establish in a larger but limited part of California.

High (3) likely to establish a widespread distribution in California.

Recent modeling data found that the majority of California could provide suitable habitat for Nutria. High elevations and deserts being the only limiting factors. Nutria could easily move throughout the inland waterways and irrigation networks.

2) Known Pest Host Range: Evaluate the host range of the pest. Score: 2

Low (1) has a very limited host range.

Medium (2) has a moderate host range.

High (3) has a wide host range.

Nutria are an aquatic species. Distribution would be limited to areas adjacent to waterways. Rivers, streams, estuaries and irrigation canals would all be suitable habitat. The interconnected waterways throughout the Sacramento-San Joaquin River and Delta and irrigated lands are all susceptible to Nutria establishment.

3) Pest Dispersal Potential: Evaluate the natural and artificial dispersal potential of the pest. Score: 3

Low (1) does not have high reproductive or dispersal potential.

Medium (2) has either high reproductive or dispersal potential.

High (3) has both high reproduction and dispersal potential.

Nutria could naturally disperse throughout the entire Sacramento-San Joaquin Bay-Delta watershed which covers over 75,000 square miles from Tehachapi to the Cascades Mountain Range. They could also establish around natural and man-made lakes, reservoirs, irrigation canals and other waterbodies.

4) Economic Impact: Evaluate the likely economic impacts of the pest to California using the criteria below. Score: 3

Economic Impact: A, B, E, G

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

Low (1) causes 0 or 1 of these impacts.

Medium (2) causes 2 of these impacts.

High (3) causes 3 or more of these impacts.

Nutria have shown to damage rice and orchards/vineyards potentially lowering crop yield and causing losses.  There is also potential for them to disrupt water delivery to crops and spread contaminants impacting food safety.  They are known to vector liver flukes and other parasites to livestock, damage water conveyance and storage infrastructure.

5) Environmental Impact: Evaluate the environmental impact of the pest on California using the criteria below. Score: 3

Environmental Impact: A, B, C, D, E

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 3

Low (1) causes none of the above to occur.

Medium (2) causes one of the above to occur.

High (3) causes two or more of the above to occur.

Nutria have contributed to massive wetland destruction and land loss. Nutria could feed directly on threatened or endangered wetland and riparian plants. Nutria have created eat-outs completely denuding vast areas of habitat, their burrowing activity also contributes to increased siltation of waterways which can impact fish habitat. Many areas of the United States currently have control and eradication programs targeting Nutria. In addition to being agricultural pests and damaging the environment Nutria have also impacted urban and residential landscaping, transmit parasites to animals and humans and become aggressive towards humans and pets.

Consequences of Introduction to California for Nutria:

Add up the total score and include it here. (14)

Low = 5-8 points

Medium = 9-12 points

High = 13-15 points

6) Post Entry Distribution and Survey Information: Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included. (-1)

Not established (0) Pest never detected in California, or known only from incursions.

Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Nutria have successfully been eradicated from California in an area close to the current location of the detections. There is only one other documented introduction in 1899 which failed to establish. There are no PDR records of other encounters in the State.

Final Score

The final score is the consequences of introduction score minus the post entry distribution and survey information score: (13)

Uncertainty

It is important to separate out uncertainty from risk. Use this section to evaluate any uncertainty associated with the introduction of the pest to California.

The three primary limiting factors of Nutria populations are harsh winters, commercial trapping and large predator populations. California has very mild winters compared to other infested areas of the world. Fur trapping is a very insignificant activity in California due to social as well as regulatory constraints and low fur prices. California does not have large populations of predators nor predators large enough to effectively take Nutria. The Southeastern U.S. has alligators and the portions of Africa that have not been impacted have many different species of large carnivores.

Conclusion and Rating Justification

Proposed rating of A.

Nutria have proven to be a significant agricultural pest in other parts of the world with similar climates and cropping systems to California. Significantly impacted crops include rice, orchards and vineyards. In addition, Nutria are a known vector of ectoparasites and diseases. Livestock are particularly susceptible to liver flukes if exposed to water soiled by Nutria excrement (Menard et al.2000). Nutria have caused extensive damage to waterways, water storage and conveyance as well as adjacent rights-of-way. Of particular concern would be the thousands of miles of earthen canal, dikes and levees comprising much of the Central Valley irrigation infrastructure (Witmer et al. 2012).

Nutria have caused extreme environmental degradation to wetlands around the United States. Their feeding behavior can produce “eat outs” which eliminate the aquatic vegetation which contains wetland and marsh soils. The subsequent erosion is extremely damaging to wetlands. In addition, this erosion combined with their burrowing activity has the potential to damage fish habitat through increased siltation. In the Chesapeake Bay estuary one of the most heavily impacted habitat types is the Spartina sp. complex similar to much of the San Francisco Bay estuary.

Due to the documented negative impacts to agriculture and the environment of Nutria establishment and the high probability of eradication in California, a rating of A is justified.

References

Carter, Jacoby, and Billy P. Leonard. “A Review of the Literature on the Worldwide Distribution, Spread of, and Efforts to Eradicate the Coypu (Myocastor coypus).” Wildlife Society Bulletin (1973-2006), vol. 30, no. 1, 2002, pp. 162–175.  www.jstor.org/stable/3784650

Chesapeake Bay Nutria Eradication Project.  “U.S. Fish and Wildlife Service Species of Concern Fact Sheet: Nutria.” (2016) Aquatic Nuisance Species Task Force.  https://www.fws.gov/chesapeakenutriaproject/

Coastwide Nutria Control Program. “Home. Nutria Control Program” (2007) Louisiana Department of Wildlife and Fisheries.  http://www.nutria.com/site9.php

Jarnevich CS, Young NE, Sheffels TR, Carter J, Sytsma MD, Talbert C “Evaluating simplistic methods to understand current distributions and forecast distribution changes under climate change scenarios: an example with coypu (Myocastor coypus).” (2017) NeoBiota 32: 107-125. https://doi.org/10.3897/neobiota.32.8884

Menard A; M. L’Hostis, G. Leray, S. Marchandeau, M. Pascal, N. Roudot, V. Michel and A. Chauvin “Inventory of Wild Rodents and Lagomorphs as Natural Hosts of Fasciola hepatica on a Farm Located in a Humid Area in Loire Atlantique (France)” (2000), Parasite, 7, 77-82 http://dx.doi.org/10.1051/parasite/2000072077

National Wetlands Research Center. “Worldwide Distribution, Spread of, and Efforts to Eradicate the Nutria (Myocastor coypus).”(2015) United Stated Geological Survey (USGS). https://www.nwrc.usgs.gov/special/nutria/namerica.htm

Pasko, Susan and Anne Marie Eich, “Species of Concern Fact Sheet: Nutria” (2011) Aquatic Nuisance Species Task Force.  https://www.anstaskforce.gov/spoc/nutria.php

Sheffels, Trevor Robert, “Status of Nutria (Myocastor coypus) Populations in the Pacific Northwest and Development of Associated Control and Management Strategies, with an Emphasis on Metropolitan Habitats” (2013).Dissertations and Thesis.Paper 665. http://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1664&context=open_access_etds

Washington Invasive Species Council. “Stop the Invasion. Nutria, Myocastor coypus” (2016) Washington Department of Fish and Wildlife. http://www.invasivespecies.wa.gov/documents/priorities/NutriaFactSheet.pdf

Witmer, Gary; Sheffels, Trevor R.; and Kendrot, Stephen R., “The Introduction, Impacts, And Management of a Large, Invasive, Aquatic Rodent in The United States” (2012). USDA National Wildlife Research Center – Staff Publications. Paper 1215. http://digitalcommons.unl.edu/icwdm_usdanwrc/1215/

Responsible Party:

David Kratville, Senior Environmental Scientist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-262-1102, plant.health[@]cdfa.ca.gov.

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Pest Rating: A

Posted by ls