Category Archives: Thysanoptera

Insects, Mites & Earthworms, Thysanoptera

Japanese Flower Thrips | Thrips setosus

California Pest Rating for
Thrips setosus Moulton: Japanese flower thrips
Photo Citation: Mound, L. (2005), PaDIL – http://www.padil.gov.au
Thrips setosus Moulton: Japanese flower thrips
Thysanoptera: Thripidae
Pest Rating:  A

 

PEST RATING PROFILE
Initiating Event:

USDA is considering changing the status of Thrips setosus from actionable to non-actionable.  A pest rating proposal is needed to advise direction on this insect.

History & Status:

Background:  Thrips setosus is a polyphagous leaf and flower-feeding thrips.  Female thrips lay eggs in leaves where they are difficult to detect and protected from chemical treatment.  Nymphs and adults feed on plants and cause silvering or bronzing of leaves and leaf scorching.  Known hosts include:  Apiaceae: hogweed (Heracleum sphondylium1); Asparagaceae: Hosta sp.1; Asteraceae: Chrysanthemum morifolium1, Erigeron sp.1, sowthistle (Sonchus oleraceus1), oriental false hawksbeard (Youngia japonica1); Balsaminaceae: Impatiens sp.1; Cucurbitaceae: cucumber (Cucumis sativus1); Euphorbiaceae: poinsettia (Euphorbia pulcherrima1); Fabaceae: soybean (Glycine max1), bean (Phaseolus vulgaris1), fava bean (Vicia faba1), asparagus bean (Vigna sesquipedaris1); Hydrangeaceae: Hydrangea sp.1; Lamiaceae: red dead-nettle (Lamium purpureum1); Pedaliaceae: sesame (Sesamum indicum1); Plantaginaceae: foxglove (Digitalis sp.1); Ranunculaceae: Helleborus sp.1; Solanaceae: bell pepper (Capsicum annum1), jimsonweed (Datura stromium1), tomato (Lycopersicum esculentum1), tobacco (Nicotiana tabacum1), Petunia x hybrid1, Carolina horsenettle (Solanum carolinense1), eggplant (Solanum melongena1); and Urticaceae: stinging nettle (Urtica dioica1). Thrips setosus has been associated with many additional plants but host records need confirmation (see uncertainty section).  Thrips setosus can be transported long distances when infested plants, cut flowers, or other fresh plant parts are moved.

Worldwide Distribution: Thrips setosus is presumably native to Japan.  From there, it has spread to Indonesia, The Republic of Korea, Croatia, France, Germany, the Netherlands, and the United Kingdom1.  In the United States, it was first found in 2016 in Michigan in a greenhouse at a nursery that imports plants from multiple nations1.  In that greenhouse, Thrips setosus was able to build up significant populations, despite existing pest management practices.  Since then, the thrips has also been found in the environment surrounding that greenhouse, in associated nursery fields located 11 miles away, and in a trace-forward survey at a greenhouse in Rhode Island1.  The thrips continues to be found in the original infested greenhouse even after multiple treatments.  Before detection, plants from that greenhouse were shipped to 39 other states, so the thrips might be more widespread.  However, trace forward surveys have not found it anywhere else.

Official Control: Thrips setosus is not known to be under official control in any other states or nations.

California Distribution:  Thrips setosus has never been found in the environment in California.

California Interceptions:  Thrips setosus has never been intercepted by CDFA.

The risk Thrips setosus (Japanese flower thrips) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Thrips setosus is polyphagous and is expected to be able to establish throughout plant hardiness zones 4 to 111. It can be expected to establish throughout almost all of California and 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: Thrips setosus is known to feed on plants in at least 26 genera in 14 plant families.  There are unverified host records on many other plants in 13 additional families.  Thrips setosus receives a High (3) 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 setosus females can lay up to 8 eggs per day and the species can complete 7-12 generations per year, depending on temperature1.  This indicates a high reproductive rate.  Thrips can be transported long distances when infested plants, cut flowers, or other fresh plant parts are moved.  Thrips setosus 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: Thrips setosus has been documented as a vector of Tomato spotted wilt tospovirus (TSWV)1.  This virus can cause bronzing, curling, necrotic streaks, or spots on tomato leaves, dark-brown streaks on leaf petioles, stems, and growing tips, and infected plants can be stunted1.  In addition, tomato fruit infected with TSWV is discolored1.  Thrips setosus is considered to be a less efficient vector of TSWV compared to thrips that are already present in California1.  However, in Michigan the thrips has not been controlled by existing thrips management programs and has not been affected by existing biological control agents.  New chemical treatments required for this thrips are likely to disrupt existing IPM programs in California agroecosystems.  Thrips setosus has not been found in other major tomato growing regions and larger populations of a thrips that is more difficult to control are expected to increase spread of the virus.  If the thrips were to establish in California it is likely to lower crop yields, especially for tomatoes.  It is certain to increase crop production costs.  It is also likely to disrupt California exports.  Thrips setosus receives a High (3) in this category.

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

Economic Impact: A, B, 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: If Thrips setosus were to establish in California it is not likely to lower biodiversity, disrupt natural communities, or change ecosystem processes. Several endangered species are closely related to possible hosts (see uncertainty section) and might be directly affected by the thrips including Ashland thistle (Cirsium ciliolatum), fountain thistle (Cirsium fontinale fontinale), Chorro Creek bog thistle (Cirsium fontinale var. obispoense), Suisun thistle (Cirsium hydrophilum var. hydrophilum), La Graciosa thistle (Cirsium loncholepis), surf thistle (Cirsium rhothophilum), Parish’s daisy (Erigeron parishii), Scott’s Valley polygonum (Polygonum hickmanii), showy Indian clover (Trifolium amoenum), Pacific grove clover (Trifolium polyodon), and Monterey clover (Trifolium trichocalyx).  Thrips setosus would not be expected to disrupt critical habitats.  It is likely to trigger new treatment programs by growers, in the nursery industry, and by residents.  Many of the host plants are popular in home/urban gardens and as ornamentals and would likely be significantly impacted by this thrips.  Thrips setosus receives a High (3) in this category.

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

Environmental Impact: B, 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.

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 Thrips setosus (Japanese flower thrips): High (15)

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: Thrips setosus has never been found 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.

–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 (15)

Uncertainty:

In addition to the known hosts described above there many other host records in the literature that have not yet been verified by USDA.  These candidate hosts include:  Amaryllidaceae: amaryllis (Hippeastrum sp.1); Asparagaceae: monkey grass (Liriope platyphylla1), mondo grass (Ophiopogon jaburan1); Asteraceae: pyrethrum (Chrysanthemum cinerariafolium1), Japanese thistle (Cirsium japonicum1), Dahlia sp.1, double Japanese aster (Kalimeris pinnatifida1), Japanese aster (Kalimeris yomena1), lettuce (Lactuca sativa1), Tagetes sp.1; Balsaminaceae: touch-me-not (Impatiens balsamina1); Brassicaceae: cabbage, broccoli, kale, brussels sprouts, collard greens, savoy, kohirabi, and gai lan (Brassica olearacea1); Caprifoliaceae: Abelia spathulata1, Cucurbitaceae: melon (Citrullus battich1), melon (Cucumis melo1), squash (Cucurbita maxima1), squash (Cucurbita moschata1), bitter melon (Momordica charantia1); Dioscoreaceae: Japanese mountain yam (Dioscorea japonica1); Ebenaceae: persimmon (Diospyros kaki1); Fabaceae: Dumasia truncata1, pea (Pisum sativum1), kudzu (Pueraria lobata1), white clover (Trifolium repens1), clover (Trifolium sp.1), vetch (Vicia sativa1); Iridaceae: Iris sp.1; Lamiaceae: henbit (Lamium amplexicaule1), wild mint (Mentha arvensis1), Moraceae: fig (Ficus carica1); Onagraceae: evening primrose (Oenothera sp.1); Poaceae: rice (Oryza sativa1); Polygonaceae: knotweed (Polygonum sp.1); Rosaceae: strawberry (Fragaria ananassa1); Rutaceae: Citrus sp.1; Simaroubaceae: tree of heaven (Ailanthus altissima1); Solanaceae: potato (Solanum tuberosum1); Vitaceae: grapevine (Vitis vinifera1); and Unknown: glory lily1.

Conclusion and Rating Justification:

Thrips setosus has only been found in greenhouses in Michigan and Rhode Island as well as several fields in Michigan associated with the infested greenhouse1.  There is uncertainty about whether or not Thrips setosus can survive in the northern United States1.  Since both Michigan and Rhode Island are northern states and the thrips has not been found elsewhere, it is not yet clear that this species has established in the United States or if it is only a regulatory incident that could be addressed.  If Thrips setosus were to establish in California it is likely to have significant impacts to crops worth as much as $14 billion annually including tomatoes, bell pepper, grapes, citrus, lettuce, melons, rice, strawberry, fig, and Brassicaceae.  The thrips would also be expected to have significant environmental impacts.  An “A” rating is justified.

References:

1 Morrice, Jarrod. 2017.  NPAG Report: Thrips setosus Moulton: Japanese flower thrips. Thysanoptera: Thripidae.  United States Department of Agriculture: Animal and Plant Health Inspection Service: Plant Protection and Quantine.  New Pest Advisory Group. Raleigh, NC.

Responsible Party:

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

Comment Period: CLOSED

7/21/2017 – 9/4/2017

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

Posted by ls

Insects, Mites & Earthworms, Thysanoptera

Dendrothrips howei Mound | Lord Howe Island Thrips

California Pest Rating for
Dendrothrips howei Mound: Lord Howe Island Thrips
Thysanoptera: Thripidae: Dendrothripinae
Pest Rating: B
PEST RATING PROFILE
Initiating Event:

Dendrothrips howei has been recently found in Contra Costa County in a sample submitted by a property manager in Concord, California. This species was first found in 2010 in nurseries at Los Angeles and Riverside counties and outdoors in 2012 in Riverside and Orange counties. Currently, this pest has a temporary Q rating. A pest rating proposal is required to assign a permanent rating for this species.

History & Status:

Background:  The subfamily Dendrothripinae is characterized by the thoracic structure and jumping abilities of the adults and it comprises a world fauna of 10 genera and more than 90 species. Members of Dendrothripinae differ from other Thripidae by the possession of lyre shaped spurs extending from the thorax (1, 3). All of these species live on young leaves, and they are usually small and jump when disturbed (2).

There are 52 species listed in genus Dendrothrips, none of which is native to any part of United States. Most of these species are known from Africa and Asia. Nine species are endemic to Europe and four from Australia. Dendrothrips howei is native to eastern Australia (4). The metamorphosis of thrips species is intermediate between simple and complete. Main hosts associated with this species include Xylosma species, Smilax australis and Trophis scandens. Eggs are laid in plant tissue or in crevices or under bark. Dendrothrips howei breeds in leaves but it is not known to vector viruses in its host plants.

Worldwide Distribution:  Dendrothrips howei is native to eastern Australia and was first recorded in Long Howe Island in 1999 (4).

Official Control: Dendrothrips howei is not known to be under official control by any other states or nations. However, in Japan, all Thripidae are listed as harmful organisms (6).

California Distribution: Dendrothrips howei was first found in a nursery in Los Angeles in 2010 and by 2012, it was considered established and causing damage to its host plants (5). It has been confirmed in the environment of San Jacinto (Riverside County – PDR 1590230), Anaheim (Orange County – PDR 300P06040111), and Concord (Contra Costa County – PDR 070P06224306).

California Interceptions:  There have been 18 records of Dendrothrips howei by CDFA through nursery regulatory activities and border station pathways between 2010 and 2016 (5).

The risk Dendrothrips howei would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Xylosma species, the main hosts of Dendrothrips howei, is grown as ornamental shrub in California. Xylosma is propagated in California nurseries and is sold as a pot plants at retail centers. Lord Howe island thrips will receive 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: Dendrothrips species are commonly associated with members of Oleaceae family (3).  However, Dendrothrips howei is known to feed mainly on Xylosma maiden and Xylosma congestum (Salicaceae). Adults have also been recorded on Trophis scandens (Moraceae) and Smilax australis. It receives a Low (1) in this category.

Evaluate the host range of the pest:

Score: 1

– 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 have a rapid reproduction rate as one generation is completed in 15-28 days depending on the host and thrips species (7). Members of sub family Dendrothripinae are often highly active, and may jump readily when even slightly disturbed. Dendrothrips howei  has become established in California feeding on leaves of Xylosma (Salicaceae). It has a high dispersal potential. The horticultural trade of its host plants continues to be a major pathway for dispersal of various thrips species (4). 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: Dendrothripinae are all leaf feeding insects, commonly associated with young leaves. Dendrothrips howei feeds on leaves and can cause distortion of new growth of host plants. This species is however not known to vector any viruses. This species may lower the quality and value of nursery grown Xylosma species by feeding on new growth and disfiguring plants. It receives a Medium (2) in this category.

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

Economic Impact: A, B

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 use

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: The establishment of Dendrothrips howei in California nurseries and landscapes is likely to trigger additional chemical treatments. Since Xylosma species are used as an ornamental plant in urban and residential areas, the establishment of Dendrothrips howei may impact cultural practices in homes and urban gardening plantings. Residents can be expected to treat or prune off distorted new growth on host plants. It receives a High (3) in this category.

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

Environmental Impact: 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.

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 Dendrothrips howei (Lord Howe Island Thrips): 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: Dendrothrips howei has been confirmed from the environment of Riverside and Orange counties, and recently at a non-contiguous area in Contra Costa County. It is likely to have become established in these areas and appears to have a widespread distribution in the state. It receives a High (-3) 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: 3

-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:

Dendrothrips howei has been found first in nursery regulatory inspections and then outdoors in certain areas of California. Most of the interceptions have been reported on containerized Xylosma plants. There have been no formal surveys done for the presence of this species in the state. Since Xylosma species are commonly used as ornamental plants in the state, it is likely that Dendrothrips howei is more widespread in California than currently recorded.

Conclusion and Rating Justification:

Impacts of Dendrothrips howei are likely to be limited to Xylosma species in California. As this species expands its distribution in California, cultural practices and possible chemical treatments would have significant environmental impacts. A “B” rating is justified.

References:
  1. Hoddle MS, Mound LA & Paris DL. 2012. Thrips of California 2012.  CBIT Publishing, Queensland, Australia.  http://keys.lucidcentral.org/keys/v3/thrips_of_california/Thrips_of_California.html.
  1. Hoddle MS, Mound LA and Nakahara S. Thysanoptera Recorded from California, USA: A Check List. Florida Entomologist 87 (3): 317-323. 2004  http://www.bioone.org/doi/full/10.1653/0015-4040(2004)087%5B0317%3ATRFCUA%5D2.0.CO%3B2
  1. Mound LA (1999), Saltatorial leaf-feeding Thysanoptera (Thripidae, Dendrothripinae) in Australia and New Caledonia, with newly recorded pests of ferns, figs and mulberries. Australian Journal of Entomology 38: 257–273 http://onlinelibrary.wiley.com/doi/10.1046/j.1440-6055.1999.00112.x/full
  1. World Thysanoptera. Identifying Thrips. Dendrothrips howei: Recognition Data. Commonwealth Scientific and Industrial Research Organization (CSIRO) http://anic.ento.csiro.au/thrips/identifying_thrips/Dendrothrips_howei.htm
  1. Pest and Damage Records, Plant Health and Pest Prevention Services, California Department of Food and Agriculture. Accessed: 01/04/2017 http://phpps.cdfa.ca.gov/user/frmLogon2.asp
  1. USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). https://pcit.aphis.usda.gov/pcit/
  1. Featured Creatures: University of Florida. Entomology and Nematology  http://entnemdept.ufl.edu/creatures/
Responsible Party:

Raj Randhawa, Senior Environmental Scientist; Dean G. Kelch, Primary Botanist; California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 654-0312; plant.health[@]cdfa.ca.gov.

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Pest Rating: B

Posted by ls

Insects, Mites & Earthworms, Thysanoptera

Biltothrips minutus (Bhatti)

California Pest Rating for
Biltothrips minutus (Bhatti)
Thysanoptera: Thripidae
Pest Rating: A
PEST RATING PROFILE
Initiating Event:

Biltothrips minutus was collected on December 8, 2016 from the head of a cabbage (Brassica oleracea) in Hawaii. This was the first interception of this species in the United States. The insect is currently unrated by CDFA, so a pest rating proposal is needed to determine future direction.

History & Status:

Background: Biltothrips minutus is a member of the Scirtothrips genus-group and it was originally described within the genus Sericothrips. The Scirtothrips genus-group lineage is comprised of 11 genera. Only two (Scirtothrips and Anascirtothrips) are widespread globally, whereas the remaining nine genera are restricted in their distributions. The members of this group breed on a wide range of plants, but they appear to prefer tissues of the youngest leaves and fruitlets. Some species of this lineage are considered major pests1.

Biltothrips minutus was described from West Bengal in India and has subsequently been reported from Thailand, Malaysia and the Society Islands in the Pacific Ocean. Biltothrips minutus lacks ocellar setae pair I, which is unique within this genus2. No literature is available concerning its biology and host plants.

Worldwide Distribution: Biltothrips minutus was described from India and has been reported in Malaysia and Thailand1. It was recently intercepted in Hawaii.

Official Control:  Biltothrips minutus is not known to be under official control by any state or nation except for Japan where all Thripidae are listed as harmful organisms4.

California Distribution: Biltothrips minutus has never been found in the environment of California3.

California Interceptions: Biltothrips minutus has not been intercepted in any regulatory situation in California3.

The risk Biltothrips minutus would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Biltothrips minutus is reported in areas with climate similar to California and is expected to encounter suitable host material throughout much of state. It receives a High (3) in this category.

 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: The host range for Biltothrips minutus is unknown, but being the members of Scirtothrips lineage they probably can feed on a variety of plants growing throughout.  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: Thrips are famous for their high reproductive rates. They may spread long distances when infested plants are moved. It receives a High (3) in this category.

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: Although there is no information available about Biltothrips minutus species as a significant economic pest, it could feed on young growth and lower crop yields. This species may lower the quality and value of nursery plants. It may also increase crop production costs by triggering additional management activities. 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, C

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: If Biltothrips minutus were to become established in California it is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. The presence of Biltothrips minutus in California may trigger additional chemical treatments in nurseries and agricultural production. It receives a Medium (2) in this category.

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

 Environmental Impact:  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 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 Biltothrips minutus: High (14)

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Biltothrips minutus has never been found 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:

Biltothrips minutus was recently intercepted in the United States for the first time and nothing much is known about its habitat and host range. Nevertheless, the environment of California is highly favorable for thrips species. Therefore, the uncertainty about this species is high.

Conclusion and Rating Justification:

Biltothrips minutus has never been found in the environment of California and its entry to the State has potentially significant economic and environmental impacts. An “A” rating is justified.

References:
  1. Ng, Y.F. and Mound, L.A. 2015. Genera of the Scirtothrips genus-group (Thysanoptera, Thripidae) with a new species of Siamothrips from Malaysia. Zootaxa 4021 (2): 387-394.   Accessed on 1-13 2017. https://www.researchgate.net/publication/283194234_Genera_of_the_Scirtothrips_genus-group_Thysanoptera_Thripidae_with_a_new_species_of_Siamothrips_from_Malaysia
  2. Ng, Y.F. and Mound, L.A. 2016. Two new species of Scirtothrips genus-group (Thripidae) of Northern Peninsular Malaysia. Zootaxa 4088 (1): 141-145.
  3. Pest and Damage Record Database, California Department of Food and Agriculture, Plant Health and Pest Prevention Services. http://phpps.cdfa.ca.gov/user/frmLogon2.asp
  4. USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). https://pcit.aphis.usda.gov/pcit/
Responsible Party:

Javaid Iqbal, California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6695; 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.

Pest Rating: A

Posted by ls

Insects, Mites & Earthworms, Thysanoptera

Retithrips syriacus (Mayet): Black vine thrips

Black Vine ThripsCalifornia Pest Rating for
Retithrips syriacus (Mayet): Black vine thrips
Thysanoptera: Thripidae
Pest Rating: A
PEST RATING PROFILE
Initiating Event:

February 26, 2014, USDA distributed a Deregulation Evaluation of Established Pests (DEEP) report proposing to change the status of Retithrips syriacus, black vine thrips, from actionable to non-actionable for the continental United States.  The thrips would remain actionable for Hawaii, Guam, and the Virgin Islands.  The insect is currently unrated by CDFA, so a pest rating proposal is needed to determine future direction.

History & Status:

Background:  Retithrips syriacus breeds on the leaves of a variety of plants in 29 plant families including grapes, roses, cotton, and castor oil2.  It may spread through trade on leaves where it has been intercepted (rarely) on various species1.

Worldwide Distribution: Retithrips syriacus is widespread in Africa and western Asia1.  It has also been found in Brazil, Venezuela, and Puerto Rico1.  It was first detected in southern Florida in 19931.

Official Control: Costa Rica, Ecuador, Japan, Jordan, the Republic of Korea, Panama, and Peru list Retithrips syriacus on their harmful organism lists1.

California Distribution:  Retithrips syriacus has never been found in the environment of California.

California Interceptions:  Retithrips syriacus has never been intercepted in California.

The risk Retithrips syriacus (black vine thrips) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: The present distribution of Retithrips syriacus corresponds to USDA plant hardiness zones 9-13, indicating that it may establish in much of California. 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: Retithrips syriacus feeds and breeds on a variety of plants in at least 29 plant families.  The thrips receives a High (3) 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.  Retithrips syriacus may move long distances in trade on nursery stock or leaves, and may be spread by wind.  One of the hosts of Retithrips syriacus is castor oil plant.  Castor oil plant is common and very abundant in riparian areas of Southern California.  If the thrips were to enter this part of the state it is likely to spread rapidly throughout the region on this host.  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: Retithrips syriacus feeds and breeds on a wide variety of plants including economically important crops such grapes, cotton, and roses.  Although the thrips has not yet caused economic damage in tropical southern Florida1, the native distribution of the thrips tends more toward a Mediterranean climate more typical of California and the thrips may be predicted to be more damaging here. Retithrips syriacus has the potential to lower yield in these crops by feeding on leaves.  The thrips may also increase crop production costs by triggering additional management activities.  Retithrips syriacus is listed as a quarantine pest by multiple countries and USDA has proposed to keep the thrips actionable in Hawaii, Guam, and the Virgin Islands.  Therefore it is probable that if Retithrips syriacus were to establish in California, it would trigger a loss of markets. This would be expected especially for exports of California table grapes.  Retithrips syriacus receives a High (3) 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: Rosa is considered a host of Retithrips syriacus.  Small-leaved rose (Rosa minutifolia) is listed as an endangered species by California and could be directly affected by the thrips.  The presence of Retithrips syriacus may also trigger additional chemical treatments in agricultural production.  The thrips receives a High (3) 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 Retithrips syriacus (Black vine thrips):  High (15)

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: Retithrips syriacus has never been found 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)

–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 (15)

Uncertainty:

It is possible that Retithrips syriacus may be managed by existing IPM practices in agriculture.

Conclusion and Rating Justification:

Retithrips syriacus is expected to find favorable conditions in California where it may have significant economic and environmental impacts.  An A-rating is justified.

References:

1Baez, Ignacio.  2014.  Deregulation Evaluation of Established Pests (DEEP); DEEP Report on Retithrips syriacus (Mayet): Black vine thrips.

2Thrips of California http://keys.lucidcentral.org/keys/v3/thrips_of_california/identify-thrips/key/california-thysanoptera-2012/Media/Html/browse_species/Retithrips_syriacus

Responsible Party:

Jason Leathers, 1220 N Street, Sacramento, CA, 95814, (916) 654-1211, 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 

Insects, Mites & Earthworms, Thysanoptera

Hercinothrips bicinctus (Bagnall): Banana-silvering Thrips

California Pest Rating for
Hercinothrips bicinctus (Bagnall): Banana-silvering Thrips
Thysanoptera: Thripidae
Pest Rating:  B
PEST RATING PROFILE
Initiating Event:

In April 2016 the Banana-silvering thrips Hercinothrips bicinctus was found by a dog-team on a shipment of Passiflora leaves from San Diego County.  A trace-back survey found that the thrips were infesting passion flower vines in an outdoor garden at a residence.  A pest rating proposal is required to assign a permanent pest rating.

History & Status:

Background:  Hercinothrips bicinctus is considered to be a polyphagous thrips that breeds on the leaves of a variety of plants, often in greenhouses1.  Nymphs and adults live on leaves, stems, and fruit.  Eggs are inserted into plant tissue2.  Primary hosts include banana, passion fruit, choko, and some weeds3.  Feeding causes leaf damage2 and silvery or brown patches on fruit2.  Infested fruit may crack, allowing decay organisms to enter2.  Hercinothrips bicinctus may be transported long distances when infested plants or fresh plant parts are moved.

Worldwide Distribution: Hercinothrips bicinctus is thought to be native to Africa1.  From there it has invaded Australia, New Zealand, Bermuda, Mexico, and Hawaii.  There is also an unconfirmed record from Brazil4.

Official Control: Hercinothrips bicinctus is listed as a harmful organism by Colombia, Costa Rica, Indonesia, Israel, Jamaica, Japan, the Republic of Korea, and Timor-Leste5.

California Distribution:  Hercinothrips bicinctus has only been found at a single residential property in San Diego County.

California Interceptions:  Hercinothrips bicinctus has only been intercepted twice in California, in June 2009 on various leis from HI, and in April 2016 on a mailed shipment of Passiflora and Persea sp. leaves from the infested property.

The risk Hercinothrips bicinctus (Banana-silvering thrips) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Based on its present tropical and subtropical distribution, Hercinothrips bicinctus is expected to establish throughout the warmer parts of coastal and southern California. It receives a Medium (2) 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: Hercinothrips bicinctus is polyphagous.  It receives a High (3) 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 have high reproductive rates and can rapidly spread long distances when infested plants or fresh plant parts are moved.  Hercinothrips bicinctus 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: Most of the damage caused by Hercinothrips bicinctus is limited to disfigured leaves and blemished fruit.  This type of damage could potentially lower the yield of production nurseries and fruit crops or increase production costs.  However, other thrips with similar biologies such as Hercinothrips femoralis (banded greenhouse thrips) are already widespread in California.  Existing management techniques for these thrips that are already present are likely to limit economic impacts from this new thrips.  However, Hercinothrips bicinctus is listed as a harmful organism by many nations and has not yet been found anywhere else in the continental United States.  It is possible that its presence in California could disrupt markets.  Hercinothrips bicinctus receives a Low (1) 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: If it becomes established in California, Hercinothrips bicinctus is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes.  However, this thrips colonized native plants as it invaded Australia and it might do the same thing in California.  Due to the polyphagous nature of the thrips this could include threatened or endangered species.  Fortunately, Hercinothrips bicinctus is not expected to disrupt critical habitats.  It could trigger new treatment programs by residents who find infested plants unsightly.  Banana plants are common ornamentals in California and will likely be significantly impacted by this pest.  Herciniothrips bicinctus receives a High (3) 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 Hercinothrips bicinctus (Banana-silvering Thrips):  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: Hercinothrips bicinctus is only known from a single residential property in San Diego County. It receives a Low (-1) 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: Medium (11)

Uncertainty:

It is possible that Hercinothrips bicinctus is more widespread in southern California.

Conclusion and Rating Justification:

Existing management practices for other thrips are likely to limit economic damage from the establishment of Hercinothrips bicinctus in California.  However, its establishment could disrupt markets and have significant environmental impacts.  A “B”-rating is justified.

References:

1 Hoddle MS, Mound LA, Paris DL. 2012. Thrips of California. CBIT Publishing, Queensland. http://keys.lucidcentral.org/keys/v3/thrips_of_california/identify-thrips/key/california-thysanoptera-2012/Media/Html/browse_species/Hercinothrips_bicinctus.htm

2 Hill, Dennis S. 2008.  Pests of Crops in Warmer Climates and Their Control. Skegness Lincs: Springer. https://books.google.com/books?id=U5dezH9_eEMC&pg=PA261&lpg=PA261&dq=Hercinothrips+bicinctus+pest&source=bl&ots=wP_kfwwlIV&sig=-XAxXb2RsC1KJE8vYQnHWgypTR8&hl=en&sa=X&ved=0ahUKEwiEoqXI1K_NAhUU-2MKHfoVDkoQ6AEISTAL#v=onepage&q=Hercinothrips%20bicinctus%20pest&f=false

3 Treverrow, N.L. 1987. Banana rust thrips and banana silvering thrips.  NSW Agriculture AGFACTS.  http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0015/120039/banana-rust-silvering-thrips.pdf

4 Mound, L.A. & R. Marullo. 1996. The Thrips of Central and South America: An Introduction: (Insecta: Thysanoptera). Memoirs on Entomology, International, 6: 1- 487.

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, Sacramento, CA, 95814, (916) 654-1211, 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:  B

Posted by ls

Insects, Mites & Earthworms, Thysanoptera

Dichromothrips smithi (Zimmerman): Bamboo Orchid Thrips

California Pest Rating for
Dichromothrips smithi
Photo Credit: http://keys.lucidcentral.org
Dichromothrips smithi (Zimmerman): Bamboo Orchid Thrips
Thysanoptera: Thripidae
Pest Rating: A
PEST RATING PROFILE
Initiating Event:

In April and May 2015 the thrips Dichromothrips smithi was found on orchids at a nursery in San Luis Obispo County.  A pest rating proposal is required to assign a permanent pest rating.

History & Status:

Background:  Dichromothrips smithi is an important pest in orchid greenhouses in Korea and Hawaii1.  The thrips feed in aggregations on flowers1.  It seems to prefer Bamboo orchids (Arundina graminifolia), but also infests other orchids in the genera Vanilla, Phalaenopsis, Spathoglottis, Dendrobium, Epidendrum, Cattleya, and Cymbidium1.  It is a pest of cultivated Vanilla in India2.  Dichromothrips smithi may be transported long distances when infested plants or cut flowers are moved.

Worldwide Distribution: Dichromothrips smithi is native to Asia where it is widespread from India to Malaysia, Indonesia, and Japan1.  It was first found in Hawaii in 20071.

Official Control: Dichromothrips smithi is listed as a harmful organism by Japan and the Republic of Korea3.

California Distribution:  Dichromothrips smithi has never been found in the environment of California.

California Interceptions:  Dichromothrips smithi has been intercepted twice by CDFA on orchids from Hawaii.

The risk Dichromothrips smithi (Bamboo orchid thrips) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Dichromothrips smithi is a tropical thrips that is likely to only establish in the warmest areas of southern and coastal California and in orchid greenhouses. It receives a Low (1) 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: Dichromothrips smithi typically feeds on eight genera of plants in the orchid family.  In China it is reported to have a much broader host range than anywhere else it has been found4.  There it is reported to feed on plants in 10 families including Amaryllidaceae, Leguminosae, Cucurbitaceae, and Solanaceae4.   It receives a High (3) 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 or rapid reproduction and local dispersal.  They may be transported long distances when infested plants or cut flowers are moved.  Dichromothrips smithi 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: Dichromothrips smithi is not expected to lower any crop yields.  It is likely to reduce the value or orchid plants by disfiguring them with its presence and feeding.  Since the thrips is not known to be present in North, Central, or South America its presence in California may disrupt markets for orchid plants and cut flowers.  It is not expected to change cultural practices, injure animals, or interfere with water supplies.  Thrips often vector viruses between plants.  Dichromothrips smithi receives a High (3) 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: Dichromothrips smithi is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes.  It is not expected to feed on threatened or endangered species or disrupt critical habitats.  It is likely to trigger additional treatment programs in the nursery and cut flower industries and by residents who find infested orchids unacceptable.  The thrips is a significant pest of orchids which are high value ornamental plants.  Dichromothrips smithi receives a High (3) 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 Dichromothrips smithi (Bamboo Orchid Thrips): 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: Dichromothrips smithi has never been found in the environment of 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.

–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:

It is unknown why Dichromothrips smithi is reported to have a much greater host range in China than it has elsewhere in its distribution.  This could be due to no-choice lab associations or taxonomic confusion.  It is possible that the thrips will be limited to orchids in California.

Conclusion and Rating Justification:

Dichromothrips smithi has never been found in the environment of California.  If it were to establish in the state it is likely to have significant economic and environmental impacts.  An “A” rating is justified.

References:

1 Hollingsworth, Robert G., Frances Calvert, and Arnold H. Hara. 2012. Dichromothrips smithi (Zimmerman), a New Thrips Species Infesting Bamboo Orchids Arundina graminifolia (D. Don) Hochr. And Commercially Grown Orchids in Hawaii.  Proceedings of the Hawaiian Entomological Society 44:1-9.  http://scholarspace.manoa.hawaii.edu/bitstream/handle/10125/25458/PHES-44_1-9.pdf?sequence=1

2 Hoddle, M.S., Mound, L.A., Paris, D.L. 2012. Thrips of California. CBIT Publishing, Queensland. http://keys.lucidcentral.org/keys/v3/thrips_of_california/identify-thrips/key/california-thysanoptera-2012/Media/Html/browse_species/Dichromothrips_smithi.htm

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

4 Liao, Qi-rong and Bo Wang. 2012. Hosts and Occurrence Regularity of Dichromothrips smithi. Guizhou Science. http://en.cnki.com.cn/Article_en/CJFDTOTAL-GZKX201203010.htm

Responsible Party:

Jason Leathers, 1220 N Street, Sacramento, CA, 95814, (916) 654-1211, 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

Insects, Mites & Earthworms, Thysanoptera

Pezothrips kellyanus (Bagnall): Kelly’s Citrus Thrips

California Pest Rating for
Pezothrips kellyanus (Bagnall): Kelly’s Citrus Thrips
Thysanoptera: Thripidae
Pest Rating: A
PEST RATING PROFILE
Initiating Event:

In May 2015 Pezothrips kellyanus was intercepted by CDFA’s high risk programs on three shipments of leis from Hawaii.  A pest rating proposal is required to assign a permanent pest rating.

History & Status:

Background:  Larvae and adult Pezothrips kellyanus feed on flowers, young leaves, and fruit1.  Where it is established it may be the most common thrips in citrus orchards3 and is considered to be a serious pest2.  Pupae overwinter in the soil and leaf litter and adults migrate to flowers as they emerge in the spring3.  Adult females lay eggs inside the tissue of flowers, fruits, and leaves2. Primary hosts are: Rutaceae: Citrus bergamia2 (bergamot orange), Citrus aurantium2 (orange), Citrus limonia2 (lemon), Citrus spp.3; Caprifoliaceae: Lonicera spp.2 (honeysuckle), Oleaceae: Jasminum fruticans2 (wild jasmine), Pittosporaceae: Pittosporum tobira2 (Japanese mock-orange).  Other hosts include: Anacardiaceae: Mangifera indica3 (mango); Apiaceae: Daucus carota (Queen Anne’s lace), Foeniculum vulgare2 (fennel); Apocynaceae: Araujia sericifera5 (moth plant); Asteraceae: Helianthus spp. (sunflower), Senecio spp.2 (ragworts), Anthemis cotula2 (stinking chamomile), Leucanthemum vulgare2 (ox-eye daisy), Sonchus oleraceus2 (common sowthistle), Calendula arvensis3 (field marigold), Urospermum picroides3 (prickly goldenfleece); Brassicaceae: Brassica spp.2 (mustard), Brassica rapa sylvestris2 (wild turnip), Sinaspis alba2 (white mustard); Fabaceae: Trifolium repens2 (white clover), Trifolium pratense2 (red clover); Lauraceae: Persea americana (avocado); Malvaceae: Malva nicaeensis3 (bull mallow), Malva sylvestris3 (common mallow); Oleaceae: Jasminum officinale3 (jasmine); Jasminum sambac3 (Arabian jasmine), Ligustrum vulgare2 (wild privet); Oxalidaceae: Oxalis pes-caprae3 (Bermuda buttercup); Pittosporaceae: Hymenosporum sp.1 (native frangipani); Rosaceae: Eriobotrya japonica3 (loquat); Prunus dulcis (almond)3; Rubus fruticosus2 (blackberry); Rubiaceae: Gardenia jasminoides3 (gardenia); Solanaceae: Lycopersicon spp.2 (tomato).  Pezothrips kellyanus may be transported long distances when infested plants, fresh plant parts, or soil or leaf litter is moved.

Worldwide Distribution: Pezothrips kellyanus is probably native to Australia1.  From there it has spread to New Zealand1, New Caledonia1, France1, Italy1, Greece1, Cyprus1, Turkey1, Spain2, Portugal2, and Israel2.  Recent interceptions indicate that it could be present in Hawaii.

Official Control: Pezothrips kellyanus is listed as a harmful organism by Chile and Japan4.

California Distribution:  Pezothrips kellyanus has never been found in the environment of California.

California Interceptions:  From 2001 and 2015 Pezothrips kellyanus has been intercepted by CDFA 13 times on shipments of leis from Hawaii.

The risk Pezothrips kellyanus (Kelly’s Citrus Thrips) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Pezothrips kellyanus is established in areas with climates similar to California and is expected to encounter suitable host material throughout much of the state. It 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: Pezothrips kellyanus is polyphagous on plants in at least 15 families.  It receives a High (3) 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: Pezothrips kellyanus has a high reproductive rate and may breed continuously throughout the year on plants that have extended flowering periods and repeated flower flushes2, such as lemons.  The thrips may spread long distances when infested plants, fresh plant parts, or soil and leaf litter are moved.  It may also spread by hitchhiking on clothing, equipment, or animals.  Pezothrips kellyanus 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: If Pezothrips kellyanus were to establish in California it may lower crop yields and lower crop value.  It is considered a serious pest in citrus orchards and its feeding can lead to reduced yields and disfigure fruit with stem-end scarring, ring-scarring with halo and scurfing, and rind discoloration2,5.  This may lead to fresh market fruit being diverted to juice production and trigger chemical treatments2.  There are many additional crops in California that may also be affected.  The presence of this thrips in California may also disrupt markets since it is listed as a harmful organism by both Japan and Chile4.  Pezothrips kellyanus is not expected to change cultural practices, injure animals, or disrupt water supplies.  It is not known as a vector of plan pathogens.  It receives a High (3) 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: If Pezothrips kellyanus were to establish in California it is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes.  It may feed on threatened and endangered species including Algodones Dunes sunflower (Helianthus niveus tephrodes), showy indian clover (Trifolium amoenum), pacific grove clover (Trifolium polyodon), and Monterey clover (Trifolium trichocalyx).  The thrips is not expected to disrupt critical habitats.  It is likely to trigger new chemical treatments in agriculture and by residents who find infested plants unsightly.  Many of the hosts of Pezothrips kellyanus are grown as ornamentals and in home gardens in California and may be significantly impacted.  Pezothrips kellyanus receives a High (3) 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 Pezothrips kellyanus (Kelly’s Citrus Thrips): High (15)

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: Pezothrips kellyanus has never been found 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.

–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 (15)

Uncertainty:

Existing IPM programs targeting other thrips that are already established in California may preclude some of the impacts from this pest.

 Conclusion and Rating Justification:

Pezothrips kellyanus has never been found in California and may have significant economic and environmental impacts if it were to establish in the state.  An “A” rating is justified.

References:

1 Hoddle MS, Mound LA, Paris DL. 2012. Thrips of California. CBIT Publishing, Queensland.

http://keys.lucidcentral.org/keys/v3/thrips_of_california/identify-thrips/key/california-thysanoptera-2012/Media/Html/browse_species/Pezothrips_kellyanus.htm

2 Marullo, Rita. EPPO Quarantine Bulletin.  Università degli Studi di Reggio Calabria

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&ved=0CC4QFjAFahUKEwj08bHclvzGAhURoogKHTm0CDk&url=http%3A%2F%2Fwww.eppo.int%2FQUARANTINE%2FPest_Risk_Analysis%2FPRAdocs_insects%2F06-12760%2520DS%2520PEZTKE.doc&ei=LZi2VbSnH5HEogS56KLIAw&usg=AFQjCNHrfJMlhro7kb2f880G5VK35jYDSA&bvm=bv.98717601,d.cGU&cad=rja

3 Vassiliou, V.A. 2010. Ecology and behavior of Pezothrips kellyanus (Thysanoptera: Thripidae) on citrus.  Journal of Economic Entomology 103(1):47-53.  http://www.ncbi.nlm.nih.gov/pubmed/20214367

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

5 Navarro-Campos, Cristina, Apostolos Peskas, Amparo Aguilar, and Ferran Garcia Mari. 2013. Factors influencing citrus fruit scarring by Pezothrips kellyanus.  Journal of Pest Science http://www.researchgate.net/publication/235993907_Factors_influencing_citrus_fruit_scarring_caused_by_Pezothrips_kellyanus

Responsible Party:

Jason Leathers, 1220 N Street, Sacramento, CA, 95814, (916) 654-1211, 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

Insects, Mites & Earthworms, Thysanoptera

Scirtothrips dorsalis Hood: (Chilli Thrips)

California Pest Rating for
Scirtothrips dorsalis Hood: (Chilli Thrips)
Thysanoptera: Thripidae
Pest Rating:  B
PEST RATING PROFILE
Initiating Event:

In August 2015 infestations of Scirtothrips dorsalis were found at several residential properties in Orange County.  A pest rating proposal is required to determine future direction on this pest.

History & Status:

Background:  Scirtothrips dorsalis is a polyphagous thrips that is reported to feed on more than 200 plant species in 70 families3.  Known hosts include economically important crops such as roses, chilies, grapes, citrus, avocado, tomato, and strawberry1,2,3.  The thrips has been recorded killing newly emerged seedlings, severely distorting leaves, scarring the surface of fruits, and vectoring major plant pathogens3.   The thrips may spread long distances through the trade of plants, fruit, or cut flowers.

Worldwide Distribution: Scirtothrips dorsalis is believed to be native to South-East Asia or the Indian subcontinent4.  It has spread across much of Asia and to parts of Australia, Papua New Guinea, and the Solomon Islands.  It has also been found on several Caribbean islands as well as in Suriname, Venezuela, and Ivory Coast1.  It was detected in Hawaii in 1987, Florida in 2005, Puerto Rico in 2006, Georgia and Texas in 2007, and Louisiana in 2009.

Official Control: Scirtothrips dorsalis is considered a quarantine pest in Europe5 and New Zealand6.

California Distribution:  Scirtothrips dorsalis has only been found in the environment of California in Orange and Los Angeles counties.

California Interceptions:  Scirtothrips dorsalis is occasionally intercepted on plants or fresh plant parts from Florida, Texas, and Hawaii.

The risk Scirtothrips dorsalis (Chilli thrips) would pose to California is evaluated below.

Consequences of Introduction: 

1)  Climate/Host Interaction: The present distribution of Scirtothrips dorsalis corresponds to USDA plant hardiness zones 8-12, indicating that it is likely to find a favorable climate in most of California. The polyphagous nature of thrips makes it likely that the insect would encounter suitable host plants throughout the state.  Chilli 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: Scirtothrips dorsalis is a polyphagous thrips that is reported to feed on more than 200 plant species in 70 families3.  Chilli thrips receives a High (3) 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: Chilli thrips reproduces rapidly:  each female lays 60-200 eggs and the thrips completes its life cycle in 12-22 days2.  The thrips is reported to disperse only 12-20m on its own1, but it may spread long distance in commerce on plants or plant parts.  Scirtothrips dorsalis 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: Although Scirtothrips dorsalis is not reported to be a significant economic pest in Florida, there could be impacts to fresh navel orange and table grape exports from California.  Citrus is a known host of the thrips, and thrips are notorious for hiding inside the navel of oranges and eluding packing house cleaning.  As chilli thrips is considered to be a quarantine pest by New Zealand and Europe, the presence of this insect in California may trigger a loss of markets.  Chilli thrips also feeds on a wide variety of ornamental plants, which it disfigures by causing leaf curling.  This may increase production costs or lower the value of nursery stock.  Chilli thrips has been reported to vector seven major plant pathogens:  chilli leaf curl virus, peanut necrosis virus, melon yellow spot virus, watermelon silver mottle virus, capsicum chlorosis virus, and tomato spotted wilt virus4.  Scirtothrips dorsalis receives a High (3) 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: Munz’s onion (Allium munzii), Yosemite onion (Allium yosemitense), and small-leaved rose (Rosa minutifolia) are listed as threatened or endangered plants in California and are potential hosts of Scirtothrips dorsalis.  The thrips is likely to trigger additional treatment programs by residents who find infested plants unsightly, as well as by the nursery industry.  Chilli thrips receives a High (3) 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 Scirtothrips dorsalis (Chilli thrips): High (15)

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: Scirtothrips dorsalis has been confirmed in Orange and Los Angeles Counties and receives a Low (-1) 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: High (14)

Uncertainty:

There have not been any statewide thrips surveys in recent years; it is possible that Scirtothrips dorsalis could have a more widespread distribution in California.  There are no effective detection technologies that would allow for a survey to delimit the infestation or find new infestations in other areas.  Because the thrips lays eggs inside plant tissue and is polyphagous, visual surveys might not find low levels of infestation in nurseries or the environment.  It is also possible that existing treatments for thrips may also limit impacts of chilli thrips.

Conclusion and Rating Justification:

The spread of Scirtothrips dorsalis through California is likely to have significant economic and environmental impacts.  However, it is already known to be established in Orange and Los Angeles Counties and is not under official control.  Scirtothrips dorsalis is already established in other states, has been proposed for deregulation by USDA, and is not known to be under consideration for FRSMP.  A “B” rating is justified.

References:

1Culliney, T.W.  2014.  Deregulation Evaluation of Established Pests (DEEP); DEEP Report on Scirtothrips dorsalis Hood: Chilli thrips.

2 Ludwig, Scott W. and C. Bográn.  2007.  Chilli Thrips: A New Pest in the Home Landscape.  Texas Cooperative Extension.  https://insects.tamu.edu/extension/publications/epubs/eee-00041.pdf

3Kumar, Vivek, Dakshina R. Seal, Garima Kakkar, Cindy L. McKenzie, and Lance S. Osborne.  2012.  New tropical fruit hosts of Scirtothrips dorsalis (Thysanoptera: Thripidae) and its relative abundance on them in south Florida.  Florida Entomologist 95(1):205-207.  http://www.bioone.org/doi/pdf/10.1653/024.095.0134

4 High Priority Organism:  Scirtothrips dorsalis (Chilli thrips).  New Zealand Kiwifruit Vine Health Inc.  http://www.kvh.org.nz/vdb/document/91534

5EPPO Data Sheets on Quarantine Pests:  Scirtothrips dorsalis.  https://www.eppo.int/QUARANTINE/insects/Scirtothrips_dorsalis/SCITDO_ds.pdf

6New Zealand Import Risk Analysis: Table Grapes (Vitis vinifera) from China.  2009.  MAF Biosecurity New Zealand.  http://www.biosecurity.govt.nz/files/regs/imports/risk/table-grapes-china-ra.pdf

Responsible Party:

Jason Leathers, 1220 N Street, Sacramento, CA, 95814, (916) 654-1211, 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:  B

Posted by ls

Insects, Mites & Earthworms, Thysanoptera

Thrips palmi (Karny): Melon Thrips

California Pest Rating for
Thrips palmi (Karny): Melon Thrips
Thysanoptera: Thripidae
Pest Rating: A
PEST RATING PROFILE
Initiating Event:

March 5, 2015 the United States Department of Agriculture announced that it is considering a change in the status of Thrips palmi, melon thrips, to non-actionable and may therefore stop taking action on the pest when it is intercepted at U.S. ports¹. A pest rating proposal is required to determine a permanent pest rating.

History & Status:

Background: Thrips palmi is a highly polyphagous insect that breeds on the flowers, stems, leaves and fruit of many species of plants and causes serious damage to food crops²,4. Crops that are often severely damaged include: Solanaceae: eggplant (Solanum melongena4), pepper (Capsicum spp.4), potato (Solanum tuberosum4), tobacco (Nicotiana tabacum4), ground cherry (Physalis spp.4); Cucurbitaceae: bittermelon (Momordica charantia4), cucumber (Cucumis sativus4), watermelon (Citrullus lanatus4), muskmelon (Cucumis melo4), cantaloupe (Cucumis melo subsp. melo4), pumpkin (Cucurbita pepo4), squash (Cucurbita spp.4), zucchini (Cucurbita pepo4), edible gourds (Cucurbita spp.4); hyotan (Lagenaria siceraria4); Leguminosae: kidney bean (Phaseolus vulgaris4), broad bean (Vicia faba4), cowpea (Vigna unguiculata4), green bean (Phaseolus vulgaris4), soybean (Glycine max4), togan (Benincasa hispida4); Amaranthaceae: chinese spinach and amaranth spinach (Amaranthus dubius4); Benincaseae: Chinese wax gourd (Benincasa hispida4); Asteraceae: Chrysanthemum spp.4, Dahlia spp.4; Malvaceae: cotton (Gossypium spp.4); Myrsinaceae: Cyclamen spp.4; Convolvulaceae: morning glory4, sweet potato (Ipomoea batatas4); Orchidaceae: orchids4; Apocynaceae: Plumeria spp.4; Pedaliaceae: sesame (Sesamum indicum4). Other reported hosts include: Lauraceae: avocado (Persea americana5); Rutaceae: Citrus spp.5; Anacardiaceae: mango (Mangifera indica5); Rosaceae: peach (Prunus persica5), plum (Prunus spp.5). Thrips palmi may be transported long distances when infested nursery stock or fresh plant parts are moved.

Worldwide Distribution: Thrips palmi is native to South-East Asia and has spread to many tropical locations throughout the world². It is established in Hawaii and Florida.

Official Control: Thrips palmi is listed as a harmful organism by 73 nations including: Albania, Antigua and Barbuda, Argentina, Armenia, Austria, Azerbaijan, Belarus, Belgium, Bermuda, Brazil, Bulgaria, Chile, Colombia, Costa Rica, Croatia, Cuba, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, French Polynesia, Georgia, Germany, Greece, Guatemala, Holy See (Vatican City State), Honduras, Hungary, Iceland, Ireland, Israel, Italy, Jamaica, Japan, Kazakhstan, Latvia, Lithuania, Luxembourg, Malta, Mexico, Moldova, Republic of Monaco, Montenegro, Morocco, Netherlands, New Zealand, Norway, Panama, Paraguay, Peru, Poland, Portugal, Romania, Russian Federation, San Marino, Serbia, Slovakia, Slovenia, South Africa, Spain, Svalbard and Jan Mayen, Sweden, Switzerland, Tajikistan, Tunisia, Turkey, Turkmenistan, Ukraine, United Kingdom, Uruguay, and Uzbekistan³.

California Distribution: Thrips palmi has never been found in the environment of California.

California Interceptions: CDFA’s high risk programs, dog teams, and border stations have intercepted Thrips palmi 64 times on consignments from Hawaii and Florida. Most interceptions have been on orchids imported from Hawaii.

The risk Thrips palmi (melon thrips) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Thrips palmi is polyphagous and suitable hosts are grown throughout the state. However, melon thrips is only known to be established in tropical climates and greenhouses; some of the colder parts of California may be unsuitable for establishment. Thrips palmi receives a Medium (2) 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: Thrips palmi feeds on more than 50 species of plants in at least 20 families. It receives a High (3) 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: Under favorable conditions, Thrips palmi can complete a generation in less than two weeks and each female can lay 100-200+ eggs. This indicates a high reproductive rate. Thrips palmi are small and are frequently hidden in pockets, cracks, and crevices on host material4. This enables them to elude inspections and facilities long distance dispersal through the movement of infested consignments. Thrips palmi 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: Thrips palmi is a primary pest of some crops and can be expected to reduce crop yields and increase crop production costs if it were to establish in California. The species is of quarantine significance to at least 73 nations and can be expected to disrupt markets for Californian agricultural commodities. Thrips palmi is also known to be an efficient vector of multiple plant pathogens including tomato spotted wilt virus5, bud necrosis virus5, and at least two other plant pathogens2. Melon thrips receives a High (3) 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: If Thrips palmi were to establish in California it could be expected to trigger additional treatment programs at farms, orchards, nurseries, and by residents. Melon thrips would also have significant impacts to home/urban gardening and ornamental plantings. Thrips palmi receives a High (3) 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 Thrips palmi (Melon Thrips): 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: Thrips palmi has never been found 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.

– 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:

The climate of California may be less suitable to the establishment of Thrips palmi.

Conclusion and Rating Justification:

Thrips palmi has not been found in California and would have significant economic and environmental impacts if it were to enter the state. An “A” rating is justified.

References:

¹ USDA Pests No Longer Regulated at U.S. Ports of Entry. http://www.aphis.usda.gov/wps/portal/aphis/ourfocus/planthealth/sa_domestic_pests_and_diseases/sa_frsmp?1dmy&urile=wcm%3apath%3a%2Faphis_content_library%2Fsa_our_focus%2Fsa_plant_health%2Fsa_domestic_pests_and_diseases%2Fsa_frsmp%2Fct_non-reg-pests

² Hoddle, M.S., Mound, L.A., Paris, D.L. 2012. Thrips of California. CBIT Publishing, Queensland. http://keys.lucidcentral.org/keys/v3/thrips_of_california/identify-thrips/key/california-thysanoptera-2012/Media/Html/browse_species/Thrips_palmi.htm

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

4 University of Hawaii Crop Knowledge Master: Thrips palmi (Karny). http://www.extento.hawaii.edu/kbase/crop/type/t_palmi.htm

5 Capinera, J.L. 2013. University of Florida Featured Creatures: Common Name: Melon Thrips. http://entnemdept.ufl.edu/creatures/veg/melon_thrips.htm

Responsible Party:

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

Pest Rating:  A

Posted by ls

Insects, Mites & Earthworms, Thysanoptera

Gynaikothrips uzeli (Zimmermann): Weeping Ficus Thrips

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:

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: 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.

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 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.

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: 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