Category Archives: Insects, Mites & Earthworms

Entomology: Insects, Mites & Earthworms

California Pest Rating for

Paracoccus hakeae Williams: A Protea Mealybug

Synonym: Phenacoccus hakeae

Hemiptera: Pseudococcidae

Pest Rating: C

PEST RATING PROFILE

Initiating Event:

In March 2013, a visual delimitation survey was conducted in a 400m radius in Los Osos (San Luis Obispo County) following the first detection of the mealybug Delottococcus confusus in California. Mealybugs collected on 10 residential properties during this survey were identified as Phenacoccus hakeae by Drs. Gillian Watson and Natalia von Ellenrieder on March 29, 2012, a new continental record.

History & Status:

Background: Phenacoccus hakeae was described from specimens collected on Hakea sericea (Proteaceae) in New South Wales, Australia¹. It has also been intercepted by USDA-APHIS on cut flowers (Persoonia sp., Leucospermum sp., and other Proteaceae) imported from Australia and also on cut flowers (presumably Proteaceae) in shipments from the Netherlands². In San Luis Obispo County, the mealybugs have been collected on Leucadendron sp. (PDRs FR0P06009425, FR0P06009426, and FR0P06009430), Protea sp. (PDRs FR0P06009383, FR0P06009384, FR0P06009386, FR0P06009387, FR0P06009389, FR0P06009400, FR0P06009401, FR0P06009421, FR0P06009423, FR0P06009427, FR0P06009429, FR0P06009431, FR0P06009433, and FR0P06009434), and Grevillea sp. (PDR FR0P06009428). Because the host plants (Proteaceae) are commonly grown for both cut flowers and landscape plants, Phenacoccus hakeae may be spread through international plant trade. The biology of the mealybug is unknown.

Worldwide Distribution: Phenacoccus hakeae is native to New South Wales, Australia. Its presence in shipments from the Netherlands suggests that it may also be present in some other countries that trade in Proteaceae.

Official Control: Phenacoccus hakeae is listed as an injurious animal on Japan’s plant pest quarantine list³.

California Distribution: In California, Phenacoccus hakeae was first known from an incursion into the environment of Los Osos, San Luis Obispo County. A follow-up survey indicates that the mealybug should be considered “established by survey” in San Luis Obispo County. In addition to Los Osos, populations have been found in the cities of Morro Bay, Shell Beach, Arroyo Grande, San Luis Obispo, Grover Beach, Cayucos, and Pismo Beach.

California Interceptions: Phenacoccus hakeae has been found in nurseries in both San Luis Obispo and Santa Barbara counties.

The risk Phenacoccus hakeae would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Proteaceae are commonly grown as ornamental plants in California and are common in the nursery industry. Phenacoccus hakeae is expected to be able to establish wherever these plants are grown. The mealybug receives a High (3) rating in this category.

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

– 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: Phenacoccus hakeae is only known to feed on plants in the family Proteaceae. P. hakeae receives a Low (1) in this category.

Evaluate the host range of the pest. Score:

– 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: Phenacoccus hakeae has demonstrated its ability to disperse long distances through the trade of ornamental plants and flowers. Mealybugs may also be dispersed by wind. They are capable of rapid reproduction. Phenacoccus hakeae receives a High (3) in this category.

Evaluate the natural and artificial dispersal potential of the pest. Score:

– 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: Phenacoccus hakeae is not documented as a pest anywhere in scientific literature. However, mealybugs may cause significant problems for protea grown for cut flowers by contaminating flowers by their presence, honeydew, and sooty mold⁴. Cut flowers are a $477 million industry in California; other states and nations might reject infested flowers. Since Phenacoccus hakeae may increase production costs and trigger the loss of markets for proteas, the mealybug receives a Medium (2) rating in this category.

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

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.

– 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: There are no plants listed as threatened or endangered in California that are expected to be hosts of Phenacoccus hakeae. Populations of the mealybug have been found established in residential areas and a botanical garden and do not appear to be triggering any additional treatment programs. Furthermore there is no evidence that any residents are replacing infested plants with alternative species. Since Phenacoccus hakeae appears to be established in the environment and is not causing any significant environmental impacts it receives a Low (1) rating in this category.

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

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:

– 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 Phenacoccus hakeae: 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: Phenacoccus hakeae is widely established in the environment of San Luis Opispo County. The mealybug 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.

– 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: Low (8)

Uncertainty:

Several species of Hakea plants are considered invasive weeds in some places; Phenacoccus hakeae may be a valuable natural enemy of these weeds or an indicator of their presence. Some mealybugs in one sample collected from Los Osos had been parasitized (PDR FR0P06009429). It is possible that parasitoids, either native to California or introduced along with the mealybugs, are helping to mitigate impacts of this new pest. It is also possible that species present in additional nations may be junior synonyms of Phenacoccus hakeae, and that the worldwide distribution of the mealybug may be greater.

It is possible that the natural habitat of Phenacoccus hakeae is sufficiently remote that its host range is not well documented. It is possible that it could colonize many other plants. High populations of the mealybug might trigger additional treatment programs in the nursery industry or by residents who find infested ornamental plants unacceptable. Large infestations of the mealybug could cause minor alterations of urban landscaping as residents and landscapers replace infested plants with alternative species.

Conclusion and Rating Justification:

Phenacoccus hakeae has established a widespread distribution on Proteaceae in San Luis Obispo County. It does not appear to be having any significant economic or environmental impacts. Therefore, a C rating is justified.

References:

¹http://www.sel.barc.usda.gov/catalogs/pseudoco/Phenacoccushakeae.htm

²http://www.aphis.usda.gov/import_export/plants/plant_imports/federal_order/downloads/2010/NetherlandsCutFlowersRevised.pdf

³http://www.ippc.int/file_uploaded/1359088733_qp_list_25July2012.pdf

⁴Mazzeo, G., J. C. Franco, and A. Russo. 2009. A new Paracoccus species from Palaearctic region (Hemiptera, Sternorrhyncha, Coccoidea, Pseudococcidae) . Zootaxa 2274: 62–68 http://www.mapress.com/zootaxa/2009/f/zt02274p068.pdf

Responsible Party:

Jason Leathers, 1220 N Street, Sacramento, CA, 95814, (916) 654-1211, plant.health[@]cdfa.ca.gov.

Pest Rating: C

Posted by ls

Coleoptera, Insects, Mites & Earthworms

Oulema melanopus (Linnaeus): Cereal Leaf Beetle

March 16, 2015 Jason Leathers

California Pest Rating for

Adult Cereal Leaf Beetle (Oulema melanopus) Image Citation: Hania Berdys, bugwood.org — Adult Cereal Leaf Beetle (*Oulema melanopus*)
Image Citation: Hania Berdys, bugwood.org

Oulema melanopus (Linnaeus): Cereal Leaf Beetle

Coleoptera: Chrysomelidae

Pest Rating: B

PEST RATING PROFILE

Initiating Event:

During late summer 2013, populations of Cereal Leaf Beetle (CLB) were found in Siskiyou and Modoc counties. Nick Condos recommended a new pest rating proposal for CLB to help determine the path forward.

History & Status:

Background: CLB is a pest of grain crops that commonly feeds on the leaves of oats, wheat, and barley. It is also reported to feed on rye, millet, corn, and many types of wild grasses. Rice is also sometimes listed as a host, but there is no evidence that CLB causes damage to rice in the scientific literature nor is CLB included in IPM guidelines for rice-producing states. Most of the damage is caused by larval beetles, known as “slugs”, feeding in the spring. Damage to leaves results in reduced photosynthetic ability in the plants and can significantly reduce grain yield. When ready to pupate, larvae drop into the soil. Adults emerge in the summer and feed briefly before entering summer aestivation. The beetles then seek out overwinter sites among the shelter of protected places such as debris and leaf litter. Historically CLB has sometimes caused severe crop losses; however, in most of the United States CLB populations are so effectively managed by introduced biological control agents, especially Tetrastichus julis, that chemical treatment is seldom required.

Worldwide Distribution: CLB is native to Europe. It was detected in Michigan in 1962 and has since spread over much of the United States. It was detected in Oregon in 1999 and by 2013 had spread to within 11 miles of the California border.

Official Control: CLB is listed as a regulated quarantine pest in New Zealand¹, Japan², and possibly other countries.

California Distribution: CLB has been found in the environment of Siskiyou and Modoc counties.

California Interceptions: CLB is commonly intercepted at California’s border stations on items such as beehives, potted plants, lumber, etc.

The risk CLB would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: In California, climate models suggest that CLB will only find favorable conditions in Del Norte County, Humboldt County, and a small portion of the central San Joaquin Valley⁴. Conditions in the southern half of California are predicted to be especially unfavorable to establishment of CLB. CLB receives a Medium (2) in this category.

2) Known Pest Host Range: CLB feeds on six different varieties of field crops and wild grasses. It 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: CLB only has one generation per year, but is capable of reaching damaging populations relatively quickly, in the absence of biological control agents. With help from the wind the beetles are thought to spread up to 10 miles/year on their own. They may move longer distances as hitchhikers on items such as lumber or beehives; however, evidence indicates that they are not likely to establish populations through this movement. According to NAPIS county records all CLB spread has been along the leading edge of the population from the original introduction, with the exception of one jump across the Dakotas³. Furthermore, wheat producing states such as Arizona and Texas do not have exterior quarantines against CLB and do not have the pest. The fact that CLB typically do not mate until after overwintering may help explain this, as mated females are unlikely to be transported while overwintering. CLB receives a Medium (2) in this category.

4) Economic Impact: Provided that biological control agents are introduced in California, CLB is not expected to significantly lower crop yield. CLB may increase crop production costs as fields will need to be scouted for the slugs to assess parasitism rates and growers may occasionally need to treat. CLB is considered a quarantine pest in some nations and could therefore, in some cases, trigger interruptions to trade or the implementation of new phytosanitary measures. CLB is not expected to negatively change normal cultural practices. CLB does not vector any other organisms, is not injurious or poisonous to agriculturally important animals, and does not interfere with water supplies. CLB receives a Medium (2) in this category.

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

– 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: CLB may require some new private treatment programs in California in the absence of biological control agents or in cases where the parasitism rate is found to be low. CLB is not expected lower biodiversity, disrupt natural communities, or change ecosystem processes. CLB is not expected to directly impact threatened or endangered species. CLB is not expected to disrupt critical habitats. CLB is not expected to significantly impact cultural practices, home/urban gardening, or ornamental plantings. CLB receives a Medium (2) in this category.

Score the pest for Environmental Impact. Score:

– 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 CLB: 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: Well established populations of CLB have been found in Siskiyou and Modoc counties. CLB receives a Low (-1) 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:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (9)

Uncertainty:

It is possible that CLB will attain a wider distribution within California than is predicted by climate models. It is also possible that several species of threatened and endangered native grasses could be favorable hosts for CLB, leading to additional environmental impacts. Furthermore, CLB populations may have established in other parts of California.

Conclusion and Rating Justification:

Provided that biological control agents are introduced to California, economic impacts from CLB are expected to be limited at most to additional pest scouting, occasional treatment, and possibly limited impacts on international trade. Environmental impacts are expected to be limited to occasional chemical treatments in cases where CLB parasitism rates are found to be low. CLB that are transported in trade nearly always fail to establish populations, showing that quarantines do not play much of a role in limiting CLB dispersal. A “B” rating is justified.

References:

¹ http://www.mpi.govt.nz/biosecurity-animal-welfare/pests-diseases/boric.aspx
² http://www.pps.go.jp/english/law/list1.html
³ http://pest.ceris.purdue.edu/map.php?code=INAMCMA#
⁴ Risk assessment for cereal leaf beetle in California through the movement of small grains, Christmas trees, and farm equipment. USDA-APHIS. 2007.

Responsible Party:

Jason Leathers, 1220 N Street, Sacramento, CA, 95814, (916) 654-1211, plant.health[@]cdfa.ca.gov.

Pest Rating: B

Posted by ls

Insects, Mites & Earthworms, Thysanoptera

Gynaikothrips uzeli (Zimmermann): Weeping Ficus Thrips

March 16, 2015 Jason Leathers

California Pest Rating for

Gynaikothrips uzeli (Zimmermann): Weeping Ficus Thrips

Thysanoptera: Phlaeothripidae

Pest Rating: B

PEST RATING PROFILE

Initiating Event:

On February 5, 2014 Dr. Gillian Watson confirmed the identification of a sample of thrips collected in Torrance, Los Angeles County as Gynaikothrips uzeli. This is a new state and county record and the species is in need of a pest rating.

History & Status:

Background: Gynaikothrips uzeli is a largely monophagous leaf-gall-forming thrips that feeds and reproduces on Ficus benjamina. The thrips forms galls on new growth¹. The thrips has also been found on Ficus obtusa, F. pilosa, F. microcarpa, and Macaranga sp.; however, it is not known to reproduce on these alternative hosts⁴. The primary pathway for the spread of Gynaikothrips uzeli is likely F. benjamina nursery stock. Many of the records from the southeastern states are on nursery stock and the thrips has been intercepted on nursery stock from Florida eight times.

Worldwide Distribution: Gynaikothrips uzeli is native to Southeast Asia including China and India¹. Over the last decade it has been invading North America. The thrips was first reported from North America in Florida in 2003¹ and has since been found in Mississippi, Alabama, Tennessee, and Louisiana¹. It has also recently been reported from Hawaii², Trinidad², Costa Rica², Belize³, Puerto Rico³, and Mexico³.

Official Control: Gynaikothrips uzeli is not known to be under official control in any states or nations⁵.

California Distribution: Gynaikothrips uzeli has only been officially collected in the cities of Torrance and Carson in Los Angeles County.
California Interceptions: Gynaikothrips uzeli has been intercepted 8 times since 2003 on nursery shipments of Ficus benjamina from Florida.

The risk Gynaikothrips uzeli (Weeping Ficus Thrips) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Ficus benjamina is a common landscape plant in California. Gynaikothrips uzeli is likely able to establish everywhere that these plants are grown. The thrips receives a High (3) in this category.

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

– 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: Gynaikothrips uzeli is only known to complete its life cycle on Ficus benjamina. The thrips receives a Low (1) in this category.

Evaluate the host range of the pest. Score:

– 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: Thrips are capable of rapid reproduction. Gynaikothrips uzeli has demonstrated its ability to move long distances on nursery stock. The thrips receives a High (3) in this category.

Evaluate the natural and artificial dispersal potential of the pest. Score:

– 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: Gynaikothrips uzeli may lower the nursery value of Ficus benjamina plants by disfiguring them with its leaf-galls and triggering chemical treatments. The thrips receives a Low (1) in this category.

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

– 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 establishment of Gynaikothrips uzeli in California is expected to trigger additional chemical treatments in the nursery industry. The thrips may also have significant cultural impacts as Ficus benjamina is a common landscape plant. Residents are likely to treat plants, increase pruning⁴, and replace heavily infested F. benjamina with alternative plants. The thrips receives a High (3) in this category.

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

Score the pest for Environmental Impact. Score:

– 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 Gynaikothrips uzeli: 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: Gynaikothrips uzeli is only known from the cities of Torrance and Carson in Los Angeles County. The thrips receives a Low (-1) 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:

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

Uncertainty:

Significant pests that are not widespread in California have been observed inside the galls produced by Gynaikothrips uzeli. For example, pink hibiscus mealybug (Maconellicoccus hirsutus) has been found living hidden inside these galls¹. It is possible that high risk exotic invasive species could travel into and spread within California inside the galls formed by G. uzeli.

There have been no surveys for Gynaikothrips uzeli within California, so it could be more widely distributed.

Conclusion and Rating Justification:

Although impacts of Gynaikothrips uzeli are expected to be limited to Ficus benjamina, this is a common landscape plant in California. Chemical treatments of hosts and changes to cultural practices as residents adapt to this pest are expected to have significant environmental impacts. Furthermore, there is the possibility that other invasive species may spread into and within California inside the galls produced by the thrips. A B-rating is justified.

References:

¹Held, D.W., D. Boyd, T. Lockley, G.B. Edwards. 2005. Gynaikothrips uzeli (Thysanoptera: Phlaeothripidae) in the southeastern United States: Distribution and review of biology. Florida Entomologist 88(4): 538-540. http://www.fcla.edu/FlaEnt/fe88p538.pdf

²Held, D.W. and D.W. Boyd, Jr. 2007. Evaluation of sticky traps and insecticides to prevent gall induction by Gynaikothrips uzeli Zimmerman (Thysanoptera: Phlaeothripidae) on Ficus benjamina. Pest Management Science. 64(2): 133-140. http://www.ncbi.nlm.nih.gov/pubmed/18069654

³Cambero-Campos, Jhonathan, Rita Valenzuela-García, Carlos Carvajal-Cazola, Claudio Rios-Velasco, and Oswaldo García-Martínez. 2010. New records for Mexico: Gynaikothrips uzeli, Androthrips ramachandrai (Thysanoptera: Phlaeothripidae) and Montanadoniola confusa (Hemiptera: Anthocoridae). Florida Entomologist 93(3): 470-472. http://www.bioone.org/doi/full/10.1653/024.093.0328

⁴ University of Florida Extension http://trec.ifas.ufl.edu/mannion/pdfs/WeepingFigThrips.pdf

⁵ USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). https://pcit.aphis.usda.gov/pcit/

Responsible Party:

Jason Leathers, 1220 ‘N’ Street, Room 221, Sacramento CA 95814, (916) 654-1211, plant.health[@]cdfa.ca.gov

Pest Rating: B

Posted by ls

Coleoptera, Insects, Mites & Earthworms

Pagiocerus frontalis (Fabricius): A Scolytid Weevil

March 16, 2015 Jason Leathers

California Pest Rating for

Pagiocerus frontalis (Fabricius): A Scolytid Weevil

Coleoptera: Cucurlionidae

Pest Rating: B

PEST RATING PROFILE

Initiating Event:

On May 21, 2014 Dr. Andrew Cline identified a beetle collected in Escondido, San Diego County, as Pagiocerus frontalis (PDR SJ0P06003026). This beetle was also reported from San Diego County in 2010. The beetle presently has a temporary rating of Q, so Dr. Kevin Hoffman recommended a pest rating proposal to determine future direction.

History & Status:

Background: Pagiocerus frontalis feeds and reproduces on the seeds of fallen avocado fruit and both fresh and dry corn. The species is considered a major pest of stored corn in the highlands of the Andes^1,2. Beetles infest corn cobs in the field before harvest and continue feeding in storage, destroying the corn within several months¹. The beetles have also been found on several other plants including coffee; however, a laboratory experiment found that these other plants were not suitable hosts for reproduction and development¹. Pagiocerus frontalis is not known to have ever been intercepted, but could presumably spread long distances when infested fresh or dry corn or ripe, damaged avocados are moved.

Worldwide Distribution: Pagiocerus frontalis is a Neotropical beetle whose range extends from South America, through Central America and Mexico, into the southeastern United States.

Official Control: Pagiocerus frontalis is listed as a quarantine pest by Japan⁴ and New Zealand⁵.

California Distribution: In California Pagiocerus frontalis has only been found in San Diego County.

California Interceptions: Pagiocerus frontalis has never been intercepted in any regulatory situations in California.

The risk Pagiocerus frontalis would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Pagiocerus frontalis has a widespread distribution across a wide variety of climates from the Andes in South America to North Carolina. It can be expected to establish wherever it can find suitable host material in California. The beetle receives a High (3) in this category.

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

2) Known Pest Host Range: Pagiocerus frontalis is only known to be able to complete its reproductive cycle on corn and the seeds of fallen avocados. It receives a Low (1) in this category.

Evaluate the host range of the pest. Score:

– 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: Pagiocerus frontalis has high reproductive potential; females lay many eggs and it can complete its entire life cycle in 3 to 4 weeks¹. The beetles may theoretically disperse long distances through the movement of infested corn or inside the seeds of ripe, damaged avocados. The beetle receives a High (3) in this category.

Evaluate the natural and artificial dispersal potential of the pest. Score:

– 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: The value of corn produced in California was approximately $812.1 million in 2012. This includes $234.7 for grain, $454.4 for silage, and $123 million for sweet. Pagiocerus frontalis might increase production costs in these crops, especially organic sweet corn. The beetle is considered a quarantine pest by some nations. The beetle therefore has the potential to disrupt markets by contaminating corn or as a hitchhiker on other commodities. Pagiocerus frontalis receives a Medium (2) in this category.

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

– 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: Pagiocerus frontalis is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. The beetle is not likely to directly affect threatened or endangered species or disrupt critical habitats. Large populations of the beetle might trigger new chemical treatments in corn when the crop is in the field or storage. Pagiocerus frontalis is not expected to significantly impact cultural practices, home/urban gardening, or ornamental plantings. The beetle receives a Medium (2) in this category.

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

Score the pest for Environmental Impact. Score:

– 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 Pagiocerus frontalis: 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: In California, Pagiocerus frontalis is only known to be established in San Diego County. The beetle receives a Low (-1) in this category.

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

Uncertainty:

There are a wide variety of pests that feed on both fresh and dry corn. It is possible that existing treatments, cultural practices, and modified genes will preclude any economic damage from this pest in California. Pagiocerus frontalis also feeds on the seed of fallen avocado. These avocados are not likely to be distributed commercially; nevertheless, the presence of this beetle might disrupt markets.

Conclusion and Rating Justification:

Pagiocerus frontalis is only known from San Diego County and has the potential to have limited economic and environmental impacts. A “B” rating is justified.

References:

¹ Eidt-Wendt, J. and F.A. Schulz. Studies on the biology and ecology of Pagiocerus frontalis (Fabricius) (Coleoptera: Scolytidae) infesting stored maize in Ecuador. Technical University Berlin, Department of Phytomedicine, Berlin, FRG. http://spiru.cgahr.ksu.edu/proj/iwcspp/pdf2/5/61.pdf

² Gianoli, E., I. Ramos, A. Alfaro-Tapia, Y. Valdéz, E.R. Echegaray, and E. Yábar. 2006. Benefits of a maize-bean-weeds mixed cropping system in Urubamba Valley, Peruvian Andes. International Journal of Pest Management. 52(4):283-289. http://www2.udec.cl/~egianoli/06gianintjpestman.pdf

⁴https://www.ippc.int/sites/default/files/documents/20130423/1309849796_qp_list_2013042321%3A18En.pdf

⁵ http://piorin.gov.pl/cms/upload/seed.pdf

Responsible Party:

Jason Leathers, 1220 ‘N’ Street, Room 221, Sacramento CA 95814, (916) 654-1211, plant.health[@]cdfa.ca.gov

Pest Rating: B

Posted by ls

Diptera, Insects, Mites & Earthworms

Horidiplosis ficifolii Harris: An Ornamental Fig Pest

March 16, 2015 Jason Leathers

California Pest Rating for

Horidiplosis ficifolii: an ornamental fig pest — *Horidiplosis ficifolii*: an Ornamental Fig Pest
Image Citation: Jakub Beránek

Horidiplosis ficifolii Harris: An Ornamental Fig Pest

Diptera: Cecidomyiidae

Pest Rating: B

PEST RATING PROFILE

Initiating Event:

On November 14, 2014, Dr. Martin Hauser identified Horidiplosis ficifolii on ornamental shrubs in San Diego (PDR 370P06228129). This is the first time this pest has been found in California. A pest rating proposal is needed.

History & Status:

Background: Horidiplosis ficifolii is a gall midge that forms galls on the leaves of ornamental Ficus spp¹. Known hosts include Ficus microcarpa^1,2, F. retusa², F. nitida², and F. panda². The gall midge may spread long distances when infested host plants are moved.

Worldwide Distribution: Horidiplosis ficifolii is native to China, Taiwan, and Japan. From there it has spread to Florida and greenhouses in Europe.

Official Control: Horidiplosis ficifolii is not known to be under official control in any other states or nations³.

California Distribution: Horidiplosis ficifolii has only been found in San Diego.

California Interceptions: Horidiplosis ficifolii has never been intercepted in regulatory situations in California.

The risk Horidiplosis ficifolii would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Ficus plants are commonly grown in California and Horidiplosis ficifolii is likely to establish where they are grown. The gall midge receives a High (3) in this category.

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

2) Known Pest Host Range: Horidiplosis ficifolii is only known to feed on four species of plants in the genus Ficus. It receives a Low (1) in this category.

Evaluate the host range of the pest. Score:

– 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: Gall midges can produce many offspring and may move long distances through commerce in infested host plants. They may also be dispersed locally by wind. Horidiplosis ficifolii receives a High (3) in this category.

Evaluate the natural and artificial dispersal potential of the pest. Score:

4) Economic Impact: Horidiplosis ficifolii may increase the production cost of Ficus spp. nursery stock and lower the value of infested plants. It is not expected to lower crop yield, trigger lost markets, change cultural practices, vector pestiferous organisms, injure animals, or interfere with water supplies. The gall midge receives a Low (1) in this category.

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

– 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: Horidiplosis ficifolii is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. The gall midge is not expected to affect threatened or endangered species or disrupt critical habitats. The gall midge may trigger new treatment programs in the nursery industry and by residents who find infested plants unsightly. Ficus spp. are commonly grown as ornamentals in California and may be significantly affected by this insect. Horidiplosis ficifolii receives a High (3) in this category.

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

Score the pest for Environmental Impact. Score:

– 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 Horidiplosis ficifolii: 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: Horidiplosis ficifolii is only known from an incursion into San Diego. It receives a Not established (0) in this category.

Final Score:

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

Uncertainty:

There have been no formal surveys for Horidiplosis ficifolii in California. It is possible that the gall midge may be more widespread. However, the species is relatively new to science, it was just described in 2003. It is possible that it may emerge as a more serious pest as it expands its range.

Conclusion and Rating Justification:

Due to its narrow host range the entry of Horidiplosis ficifolii is expected to have limited economic consequences. However, it may have significant environmental impacts by triggering new chemical treatments in the nursery industry and by residents who find infested ornamental plants unsightly. A “B” rating is justified.

References:

¹Steck, Gary J. and Scott Krueger. An Ornamental Fig Pest, Horidiplosis ficifolii Harris (Diptera: Cecidomyiidae), Genus and Species New to Florida and North America. Florida Department of Agriculture and Consumer Services. http://www.freshfromflorida.com/Divisions-Offices/Plant-Industry/Plant-Industry-Publications/Pest-Alerts/Pest-Alerts-An-Ornamental-Fig-Pest-Horidiplosis-Ficifolii-Harris-Diptera-Cecidomyiidae

²Beránek, Jakub and Ivana Šafránková. 2010. First record of Horidiplosis ficifolii Harris 2003 (Diptera: Cecidomyiidae) in the Czech Republic. Plant Protect. Sci. 46(4): 185-187. http://www.agriculturejournals.cz/publicFiles/31854.pdf

³USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). https://pcit.aphis.usda.gov/pcit/