Tag Archives: Thysanoptera: Thripdae

Japanese Flower Thrips | Thrips setosus

California Pest Rating for
Photo Citation: Mound, L. (2005), PaDIL - http://www.padil.gov.au
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 discolored1Thrips 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

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.


Comment Period:  CLOSED

3/3/2017 – 4/17/2017

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

Dichromothrips smithi (Zimmerman): Bamboo Orchid Thrips

California Pest Rating for
Photo Credit: http://keys.lucidcentral.org
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:

BackgroundDichromothrips 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 India2Dichromothrips 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 DistributionDichromothrips smithi has never been found in the environment of California.

California InterceptionsDichromothrips 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 Period:  CLOSED

The 45-day comment period opened on April 7, 2016 and closed on May 22, 2016.


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