Cotton Bud Thrips | Frankliniella schultzei

California Pest Rating  for
Cotton Bud Thrips | Frankliniella schultzei Trybom
Thysanoptera: Thripidae
Pest Rating: A



Initiating Event:

Frankliniella schultzei, cotton bud thrips, is intercepted regularly through CDFA regulatory activities. It was intercepted 6 times in 2017 and most recently on January 23, 2018 at the Winterhaven Border Station in a shipment of cut flowers, originating from Miami, Florida and destined for San Diego. Currently, it has a temporary rating of “Q”.  A pest rating proposal is required to assign a permanent rating for this species.

History & Status:

BackgroundFrankliniella schultzei is a highly polyphagous pest that has been recorded from 83 species of plants among 35 families (Palmer 1990). It feeds on ornamental, fruits and vegetable hosts in different parts of the world. It can cause direct damage to host plants by feeding injury and by laying eggs in the leaves. Indirect damage includes pale spots and stripes on flowers caused by transmission of tospoviruses (Plantwise Knowledge Bank, 2017).

Frankliniella schultzei occurs in pale and dark forms. The pale form is yellow with brownish blotches. The dark form is uniformly dark brown. These two forms are morphologically similar to each other. In the United States, the dark form is distributed in Florida and Colorado whereas the light form is found in Hawaii (Kakkar et al. 2017). There are two larval and two inactive and non-feeding stages (prepupa and pupa). The complete life cycle takes approximately 12.6 days.

Major hosts of Frankliniella schultzei are cotton, groundnut, beans and pigeon pea. However, it also attacks chilies, coffee, onion, potato, sorghum, sunflower, sweet potato and tomato among others (Hill 1975).

Worldwide Distribution: Frankliniella schultzei is thought to originate from South America, although there is a possibility that it came from Africa (Hoddle 2012). It has a wide distribution and is mainly found in tropical and subtropical areas of the world including Africa, Asia, Australia, the South Pacific, Central America, the Caribbean, Europe and North America (Kakkar et al. 2012).

In the United States, Frankliniella schultzei has been reported to be present in central and southern Florida, Colorado and Hawaii (CABI 2017).

Official Control: Frankliniella schultzei is listed as a harmful organism in Armenia, Belarus, Costa Rica, Guatemala, Japan, Kazakhstan, Kyrgyzstan, Panama and the Russian Federation (USDA APHIS- PCIT).

California DistributionFrankliniella schultzei was found once in the environment of California, in Los Angeles County.

California Interceptions: Frankliniella schultzei has been intercepted 33 times by CDFA through various regulatory pathways mainly through border station inspections and, nursery regulatory and high-risk pest exclusion activities.

The risk Frankliniella schultzei (cotton bud thrips) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Areas of California with tropical and subtropical climates are likely to be favorable for many host plants of Frankliniella schultzei. Hosts like tomatoes, cucurbits, cotton, rice, strawberry, peach, avocado, onions and carnation are grown throughout 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: Frankliniella schultzei is a highly polyphagous pest that has been reported to attack 83 host plant species in 35 families. Major host include onion (Allium cepa),  pineapple (Ananas comosus), groundnut (Arachis hypogaea), cacti (Cactaceae), pigeon pea (Cajanus cajan), bell pepper (Capsicum annuum), thistle (Cirsium), watermelon (Citrullus lanatus), melon (Cucumis melo), pumpkin (Cucurbita sp.), carnation (Dianthus), Lisianthus (Eustoma grandiflorum), strawberry (Fragaria ananassa), soyabean (Glycine max), cotton (Gossypium sp.), Bourbon cotton (Gossypium hirsutum), hyacinth (Hyacinthus), bully tree (Hyeronima alchorneoides), irises (Iris), lettuce (Lactuca sativa), lentil (Lens culinaris subsp. culinaris), mango (Mangifera indica), tobacco (Nicotiana tabacum), orchids (Orchidaceae), rice (Oryza sativa), avocado (Persea americana), common bean (Phaseolus vulgaris), peach (Prunus persica), roses (Rosa), African violet (Saintpaulia ionantha), tomato (Solanum lycopersicum), aubergine (Solanum melongena), spinach (Spinacia oleracea), African marigold (Tagetes erecta), black gram (Vigna mungo) and cowpea (Vigna unguiculata) (Plant Wise Knowledge Bank, 2017). 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: Frankliniella schultzei females inserts their eggs in flower tissue. One generation is completed in 12.6 days at 24°C (Kakkar et al.2017).  When females feed on larval diet of Malvavicus arboreus and sucrose, they can produce about 60 eggs at 77°F (Milne et. al. 1996). It can disperse rapidly with air currents to colonize new areas. It receives a Medium (2) 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: Frankliniella schultzei adults and nymphs feed on pollen and floral tissue resulting in abortion of flowers. Direct damage causes discoloration and stunted growth of the plant (Palmer 1985). Indirect damage is caused by transmission of tomato spotted wilt virus (Tospovirus) and tomato chlorotic spot virus (TCSV). The dark form of schultzei is mainly responsible for vectoring tospovirus and TCSV, whereas the pale form is a weak vector. (Kakkar et al., 2017). It receives a High (3) in this category

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

– 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: Frankliniella schultzei is not likely to lower biodiversity and disrupt natural communities. It is also not expected to affect threatened or endangered species. However, since many of the host plants are grown in California gardens, infestation by schultzei could trigger additional chemical treatment by homeowners. If this species gets established in California, cultural practices could be significantly impacted. For example, the following practices may be required: flood irrigation to destroy large pupal populations, use of horticultural oils to repel adults and reduce oviposition, and growing trap crops and manipulation of vegetation adjacent to host crops to repel this species. (Plant-wise Knowledge Bank, 2017). It receives a High (3) in this category.

Evaluate the environmental impacts of the pest on California using the following criterion: 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:

– 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 Frankliniella schultzei (cotton bud 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: Frankliniella schultzei was detected in the natural environment of California once. It receives Low (-1) in this category.

Evaluate the known distribution in California. Only official records of specimens 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)


Frankliniella schultzei has been found in the environment in California once on roses in a residence garden in Los Angeles County. The status of that infestation is unknown, as well as if the species became established and is present in a wider area or not. The species is intercepted by CDFA mostly on shipments of cut flowers, potted plants and perishable vegetables coming to California. There are many nurseries and florists in California that sell cut flowers and potted plants. California’s favorable climate and presence of several major hosts of F. schultzei, including cotton, make this thrips species a threat to the agriculture industry of the state. Presence of native thrips species like F. occidentalis and others in California could delay early detections of F. schultzei. Therefore, additional surveys could aid in early detections and rapid eradication from the state. Vigilant inspections of shipments from Florida and Hawaii as well as border station inspections are essential to prevent the introduction of F. schultzei to California.

Conclusion and Rating Justification:

Frankliniella schultzei is expected to have significant economic and environmental impacts because of the presence of several host plants species and their importance to the state’s agriculture resources. Based on all of the above evidence provided, an “A” rating is justified.


Amin P.W. and Palmer JM. 1985. Identification of groundnut Thysanoptera. Tropical Pest Management 31: 268-291

CABI, 2017. Frankliniella schultzei.  Invasive species compendium. Wallingford, UK: CAB international, Accessed 2/15/2018

CABI Plant Wise Knowledge Bank. Technical factsheet. Frankliniella schultzei. Accessed 2/15/2018

Hill DS. 1975. Agricultural Insect Pests of the Tropics and Their Control, Cambridge University Press, London.

Hoddle M.S., Mound L.A., Paris DL. 2012. Thrips of California. CBIT Publishing, Queensland. Accessed 2/15/2018

Kakkar, G., Seal. R. D. & V. Kumar, 2017. Featured Creatures. Frankliniella schultzei. Publication Number EENY-477 Entomology and Nematology Department, University of Florida. Accessed 2/15/2018

Kakkar, G., Seal D.R. & V. Kumar. 2012. Assessing abundance and distribution of an invasive thrips Frankliniella schultzei (Thysanoptera: Thripidae) in South Florida. Bulletin of Entomological Research.102: 249-259.

Milne, M. & G.H. Walter. 1997. The significance of prey in the diet of the phytophagous thrips, Frankliniella schultzei. Ecological Entomology. 22: 74-81.

Palmer J.M. 1990. Identification of the common thrips of tropical Africa (Thysanoptera: Insecta). Tropical Pest Management 36: 27-49.

USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Assessed 2/14/2018


Raj Randhawa, 1220 ‘N’ Street, Room 221, Sacramento CA 95814, (916) 403-6617,[@]

Responsible Party:

Jason Leathers, 2800 Gateway Oaks, Sacramento CA 95833, (916) 654-1211,[@]

Comment Period:* CLOSED

4/12/18 – 5/27/18


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Pest Rating: A


Posted by ls