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Chilli Thrips (castor thrips, Assam thrips, yellow tea thrips, strawberry thrips), Scirtothrips dorsalis Hood, Provisional Management Guidelines1
D. R. Seal and W. Klassen2Description
Adult thrips are small about 0.5 - 1.2 mm long. It is difficult to recognize this thrips with the naked eye, and definitive identification is best accomplished at approximately 40 to 80 x magnification. Eggs are about 0.075 mm long and 0.070 mm wide, and are inserted inside plant tissue. The egg stage lasts for 6-8 days, which is followed by two larval stages (1st and 2nd instars) that last for 6-7 days. The prepupal period is short (~ 24 h) and the pupal period lasts 2-3 days. The larvae are off-white. Also the adults are pale yellow to grayish-white in color with incomplete dark stripes on the dorsal surface where adjacent abdominal segments meet. The life cycle is completed in 14-20 days. The chilli thrips female oviposits 60 to 200 eggs in her life time at the rate of 2-4 eggs per day.
CREDITS: Laurence MOund, CSIRO Division of Entomology, Australia
Figure 1. Scirtothrips dorsalis adult showing the incomplete dark stripes on the dorsal surface where adjacent abdominal segments meet. Symptoms
Chilli thrips attacks all above ground parts of its host plants, and prefers the young leaves, buds and fruits. Heavy feeding damage turns tender leaves, buds, and fruits bronze to black in color. Damaged leaves curl upward and appear distorted. Infested plants become stunted or dwarfed, and leaves with petioles detach from the stem, causing defoliation in some plants. The abundance of chilli thrips is low in the rainy season, but becomes high during the dry season.
CREDITS: M. A. Ciomperlik, APHIS, USDA
Figure 2. Curling of pepper leaves caused by feeding of S. dorsalis. Sampling Plan
It is important to check plants with abnormal growth. At the initial stage of infestation, the underside surfaces of the leaves become shiny. These leaves soon become discolored and curly. Collect 5-20 leaves from the symptomatic plants and place them in a ziplock bag to prevent adults from escaping. Label the bag with collection locality information, host plant, date collected and name of collector. and send these samples for next-day delivery to an expert for further processing to establish or confirm their identity.Management
Studies were conducted recently on St. Vincent to evaluate various insecticides in controlling chilli thrips in pepper. The insecticides listed in the tables below were found to suppress the chilli thrips. For detailed information about the effectiveness of these insecticides, consult the manuscript titled `Comparative effectiveness of chemical insecticides against the chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), on pepper and their compatibility with natural enemie's at http://cta.ufl.edu/thrips.htm .Federal and Florida laws require that all pesticides must be handled and applied in strict accordance with the label and worker protection standards (re-entry times, protective clothing, etc.). For complete information pertaining to use of any insecticide, follow the label. Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture or the University of Florida.
References
Amin, B. W. 1979. Leaf fall disease of chilly and pepper in Maharashtra, India. Pans, 25: 131-134.Amin, P. W., Reddy, D. V. R., Ghanekar, A. M. 1981. Transmission of tomato spotted wilt virus, the causal agent of bud necrosis of peanut, by Scirtothrips dorsalis and Frankliniella schultzei. Plant Disease 65: 663-665.
CABI. 2003. Crop protection compendium: global module. CABI Publishing, Wallingford, UK.
Chang, N. T., Parkeker, B. L., Skinner, M., Lewis, T. 1995. Major pest thrips in Taiwan, pp. 105 - 108, Thrips biology and management: Proceedings of the 1993 International Conference on Thysanoptera. Plenum Press, New York.
Chu, C. C., M. A. Ciomperlik, Niann-Tai Chang, M. Richards, and T. J. Henneberry. 2005. Developing and evaluating traps for monitoring Scirtothrips dorsalis (Hood) Florida Entomologist (submitted).
EPPO and CABI. 2003. Scirtothrips dorsalis. Data Sheets on Quarantine Pests. In: Quarantine Pests for Europe. 2nd edition. No. 142. CAB International, Wallingford, UK.
FNGLA. (Florida Nursery, Growers and Landscape Association). 2003. The unlucky 13. Report of the Major Nursery Pest & Disease Identification Task Force. Florida Nursery Growers, and Landscape Association, Orlando, Florida, USA. 1 p.
Hoddle, M.S. and L. A. Mound. 2003. The genus Scirtothrips in Australia (Insecta, Thysanoptera, Thripidae). Zootaxa 268: 1-40
Kodomari, S. 1978. Control of yellow tea thrips, Scirtothrips dorsalis Hood, in tea field at east region in Shizuoka Prefecture. Tea Research Journal, No. 48: 46-51.
Meissner, H., A. Lemay, D. Borchert, B. Nietschke, A. Neeley, R. Magarey, M. Ciomperlik, C. Brodel and T. Dobbs. 2005. Evaluation of possible pathways of introduction of Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) from the Caribbean into the continental United States. Center for Plant Health Science and Technology
Mound, L. A., Palmer, J. M. 1981. Identification, distribution and host plants of the pest species of Scirtothrips (Thysanoptera: Thripidae). Bulletin of Entomological Research 71: 467-479.
Sanap, M. M. and R. N. Nawale. 1987. Chemical control of chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae). Vegetable Science 14(2): 195-199.
Saxena, P., Vijayaraghavan, M. R., Sarbhoy, R. K., Raizada, U. 1996. Pollination and gene flow in chillies with Scirtothrips dorsalis as pollen vectors. Phytomorphology 46: 317-327.
Seal, D. R., M. Ciomperlik, M. L. Richards and W. Klassen. 2005. Distribution of the Chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), within pepper plants and within pepper fields on St. Vincent. Florida Entomologist (submitted).
Seal, D. R., M. Ciomperlik, M. L. Richards and W. Klassen. 2005. Comparative effectiveness of chemical insecticides against the chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), on pepper and their compatibility with natural enemies. Crop Protection (submitted).
Suwanbutr, S., Tongklad, C., Uhnchit, W., Thayamanon, P., Witthayarug, W. Khewpoompung, P. 1992. A field trial on the efficacy of some insecticides for controlling thrips attacking pummelo. Proceedings of the International Symposium on Tropical Fruit: Frontier in Tropical Fruit Research. Pattaya City, Thailand, 20-24 May 1991. Acta Horticulturae 321: 876-881.
Tsuchiya, M., Masui, S. Kuboyama, N. 995. Color attraction of yellow tea thrips (Scirtothrips dorsalis Hood). Japanese Journal of Applied Entomology and Zoology 39: 299-303.
Venette, R.C., Davis, E.E. 2004. Chilli thrips/yellow thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) Mini Pest Risk Assessment. Univ. of Minnesota, St. Paul, MN, USA. 31 pp.
Tables
Table 1. Insecticides for controlling chilli thrips on ornamentals.
Active Ingredient
Trade Name
Pesticide Class
Signal Word
Application
Novaluron
Pedestal SC
Benzoylphenyl urea
Caution
Foliar spray
1Chlorofenapyr
Pylon
Pyrrole
Foliar spray
Imidacloprid
Marathon 60 WP
Neonicotinoid
Caution
Foliar spray
Spinosyn A + B
Conserve SC
Spinosyn
Caution
Foliar spray
Abamectin
Avid 0.15 EC
Avermectin
Warning
Foliar spray
Cyfluthrin
Tempo 2
Pyrethroid
Warning
Foliar spray
Azadirachtin
Azatin XL
Botanical
Caution
Foliar spray
Azadirachtin
Ornazin 3 EC
Botanical
Warning
Foliar spray
1 Use restricted to greenhouses.
NOTE: Each insecticide should be used sparingly and rotated with one or more others each of a different class. As information comes available on the effectiveness against this pest of indigenous or introduced biological control agents, measures to integrate their use will be critically important in achieving sustainable suppression.
Table 2. Insecticides for controlling chilli thrips on fruits and vegetables.
Active Ingredient
Trade Name
Pesticide Class
Signal Word
Application
Novaluron
Ramon 0.83 EC
Benzoylphenyl urea
Caution
Foliar spray
1Chlorofenapyr
Pylon
Pyrrole
Foliar spray
Imidacloprid
Provado
Neonicotinoid
Caution
Foliar spray
Spinosyn A + B
SpinTor 2 SC
Spinosyn
Caution
Foliar spray
Abamectin
Agrimek 0.15 EC
Avermectin
Warning
Foliar spray
Cyfluthrin
Baythroid 2
Pyrethroid
Danger
Foliar spray
Azadirachtin
Neemix 4.5
Botanical
Caution
Foliar spray
1 Use restricted to greenhouses.
NOTE: Each insecticide should be used sparingly and rotated with one or more others each of a different class. As information comes available on the effectiveness against this pest of indigenous or introduced biological control agents, measures to integrate their use will be critically important in achieving sustainable suppression.
Footnotes
1. This document is ENY-725 (IN638), one of a series of the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. First published: November 2005. Please visit the EDIS Website at http://edis.ifas.ufl.edu.2. D. R. Seal and W. Klassen, Department of Entomology and Nematology, University of Florida-IFAS, Tropical Research and Education Center, Homestead, FL 33031.
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U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry Arrington, Dean.
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