Rose Thrips | Thrips fuscipennis | Pest Rating Proposals and Final Ratings

California Pest Rating for

***Thrips fuscipennis*: Rose Thrips**

Thysanoptera: Thripidae

Pest Rating: A

PEST RATING PROFILE

Initiating Event:

In November 13, 2016, five thrips were intercepted at Needles inspection station from a truck coming from New Jersey heading to Los Angeles on a load of kiwi (Shipment size: 40,000 lbs) originating from Italy and were identified as Thrips fuscipennis. Previously, this species had been intercepted twice in 2012 through CDFA border stations and high risk pest exclusion inspections. A temporary rating of “Q” has been assigned. This pest rating proposal was prepared to determine a permanent pest rating.

History & Status:

Background: Thripini is the most phylogenetically diverse tribe in the family Thripidae, and Thrips is a highly evolved genus in subfamily Thripinae. Thrips fuscipennis is one of the commonly intercepted thrips in at U.S. ports of entry from Africa, Europe, and the Mediterranean. It is a polyphagous species characterized by the presence of ctenidia on abdominal tergites (4). The body length is 1.2-1.4mm, antennae are seven segmented and head is broader relative to most other thrips (5). Life stages consist of an egg, a first and a second larval stage, the propupal and pupal stage, and the adult stage. Reproduction is sexual or parthenogenetic. Eggs are laid in slits cut with the ovipositor into the host plant. Fertilized eggs produce females and unfertilized eggs produce males. One generation is completed in about one month. Thrips overwinter normally as a second stage larva or an adult female in bark crevices or plant debris (4). Hosts plants that Thrips fuscipennis can damage include roses, strawberries, bell pepper and white clover (3). Adult thrips are poor fliers but their feathery wings allow them to be readily carried by winds (6).

Worldwide Distribution: Thrips fuscipennis is native to England and present in Europe. It is currently distributed in Asia: China; Europe: Albania, Austria, Czech Republic, Denmark, England, Estonia, Finland, France, Germany, Hungary, Ireland, Italy, Lithuania, Netherlands, Poland, Romania, Russia, Sardinia, Scotland, Serbia, Slovakia, Sweden, Switzerland, Trancaucasia, Turkey, Wales, and the former Yugoslavia. North America Canada (British Columbia, Quebec) (5).

US Distribution: The first record of Thrips fuscipennis in North America was made by Hood based on his identification of a female collected in Ithaca, New York in July, 1926, on Angelica atropurpurea. This was later identified as Thrips fallaciosus. The first verified record of Thrips fuscipennis was reported from North America by Chaisson in 1986 in British Columbia. The various records of this species from Canada and the United States were misidentification of Thrips fallaciosus, which is widely distributed from Alaska and Labrador south to Utah, Colorado, Iowa, Illinois, and New York but has not been recorded from California to date(4).

Official Control: Thrips fuscipennis is listed as harmful organism by Costa Rica, Japan, Republic of Korea and Taiwan (9).

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

California Interceptions: Thrips fuscipennis has been intercepted three times through CDFA’s border stations and high risk pest exclusion programs (7).

The risk Thrips fuscipennis (rose thrips) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Thrips fuscipennis is polyphagous and its hosts are grown throughout the state. This species can become established in areas of the state with warm spring and summers. Rain can wash thrips larvae from the hosts but if host plants are stressed due to drought, thrips infestations and populations can increase (4). 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: Thrips fuscipennis has a wide host range including ornamentals, fruit crops, legumes, cucumber, bind weed, meadowsweet (1). Common hosts include Roses (Rosa), Strawberry (Fragaria), bell pepper (Capsicum annuum) and white clover (Trifolium repens) and canola (Brassica napus (3). 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: Reproduction of thrips is sexual or parthenogenetic. Each female lays about 100 eggs in its life time. Fertilized eggs produce females and males are produced from unfertilized eggs. One generation is completed in a month, but this can vary depending upon temperature. Adults are poor fliers but their feathery wings allow them to be readily carried by air currents (4, 6). Eggs concealed in plant tissue can easily be transported long distances when infested plants or cuttings are moved. It receives a Medium (2) 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: Thrips fuscipennis is reported as a serious pest of deciduous trees and shrubs in ornamental nurseries in central and southern Poland. This was the main species encountered on plum and apple twigs in nurseries, mother apple plantations and in young orchards (2). This species can also cause fruit bronzing in strawberries resulting in lower fruit quality (1). If this species were to enter California, it would be likely to impact fruit crops and ornamental plantings. Since Thrips fuscipennis is commonly intercepted at US ports of entry, this species is likely to trigger quarantine for California commodities. Thrips can also be vectors of bacteria, fungi and viruses. 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, 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.

5) Environmental Impact: Thrips fuscipennis is not expected to lower biodiversity or change ecosystem processes. However, it is likely to have impacts on Monterey clover (Trifolium trichocalyx), showy Indian clover (Trifolium amoenum) and pacific grove clover (Trifolium polyodon), listed as state and federally endangered species in California (8). The establishment of Thrips fuscipennis is also likely to trigger additional treatments programs at orchards, ornamental nurseries and home gardens. It receives a High (3) in this category

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

Environmental Impact: B, D

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

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

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

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

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

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 Thrips fuscipennis (rose 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 fuscipennis has never been found in the environment and receives a Not established (0) in this category.

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

Score: 0

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

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

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

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

Final Score:

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

Uncertainty:

Current ongoing integrated pest management programs against western flower thrips and other thrips species may be beneficial against Thrips fuiscipennis. It is not known how many native and wild Trifolium and other species can be impacted if Thrips fuscipennis were to get established in the state. There have been no surveys done within California nurseries and orchard planting so this species might be present in certain areas of the state.

Conclusion and Rating Justification:

Rose thrips (Thrips fuscipennis) has never been found in the environment of California and would likely have significant economic and somewhat environmental impacts if it were to enter the state. An “A”-rating is justified.

References:

Agriculture and Horticulture Development Board, United Kingdom: Thrips fuscipennis A ‘new’ pest of Strawberry – AHDB Horticulture, Accessed 02/03/2017 https://horticulture.ahdb.org.uk/sites/default/files/4%20Jude%20Bennison%20-%20Thrips%20fuscipennis.pdf | https://horticulture.ahdb.org.uk/…/4%20Jude%20Bennison%20-%20Thrips%20fuscip…

Czubik, Teresa Badowska and Olszak Remigiusz W. 2006. Thripidae in Polish plum and apple nurseries and orchards. Journal of fruit and ornamental plant research. Vol. 14 ( Suppl.3)
http://www.inhort.pl/files/journal_pdf/Suppl_3_2006/Suppl_3_full_15_2006.pdf

CABI 2016. Thrips fuscipennis http://www.cabi.org/cpc/datasheet/53734

Nakahara, Sueo 1994. The Genus Thrips Linnaeus (Thysanopetera: Thripidae) of the New World. USDA ARS Technical Bulletin: 1822, July 1994 https://naldc.nal.usda.gov/naldc/download.xhtml?id=CAT11137035&content=PDF

A. David: Commonly intercepted Thrips at U.S. Ports-of-entry from Africa, Europe, and the Mediterranean. Ill. THE Genus Thrips Linnaeus, 1758 (Thysanoptera: Thripidae).Proceedings of the Entomological Society of Washington. Jan 2008: Vol. 110, Issue 1, pg(s) 165-185 https://naldc.nal.usda.gov/download/10094/PDF

Ministry of Agriculture, British Columbia. Thrips- Biology and Control in Floriculture Crops http://www2.gov.bc.ca/assets/gov/farming-natural-resources-and-industry/agriculture-and-seafood/animal-and-crops/plant-health/thrips-floriculture.pdf

Pest and Damage Record Database. Plant Health and Pest Prevention Services, California Department of Food and Agriculture, Accessed: 02/03/2017 http://phpps.cdfa.ca.gov/user/frmLogon2.asp

State of California Natural Diversity Database 2012. State and federally listed Endangered, Threatened and Rare plants of California, Resource Management and Planning Division, Biogeographic Data Branch. CA Department of Fish and Game.

USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Accessed: 02/03/2017. https://pcit.aphis.usda.gov/pcit/

Responsible Party:

Raj Randhawa, Senior Environmental Scientist; 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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