Ecology and Management of Scirtothrips dorsalis

1. Ecology and Management of Scirtothrips dorsalis Presented By: Dr. Joe Funderburk, UF/IFAS Contributing Authors: UF/IFAS: J. Funderburk, and L. Osborne A.C. Hodges, UF/IFAS, SPDN (ed.)

2. POPULATION ATTRIBUTES OF THRIPS ◦ Vagile (excellent invaders, mobile)◦ Broad host range◦ Short generation time◦ Predisposition to parthenogenesis◦ A competitive breeding structure promoting aggregation and exploitation of localized optimal conditions Mound. 1997. Thrips As Crop Pests (Lewis, ed.) CAB International

3. Host Range for Frankliniella occidentalis • 50 of 55 plant species in 22 families were food hosts for the adults in a survey in Central Chile • 43 of 55 plant species were reproductive hosts

4. Plant Hosts for Frankliniella occidentalis in the Aconcogue Valley, Chile Number of Families or Species Ripa, Rodriguez, Funderburk, & Espinoza, unpublished

5. Life History of Pest Thrips • 30 to 40 days for a complete generation • 6, 5, and 5 days for development of egg, larva, and pupa • Pollen doubles or triples fecundity • Strong aggregation tendencies for flowers of Thrips and Frankliniella species • Scirtothrips aggregate on young foliage and flowers

7. Reproduction in Thrips • In most Thysanoptera, reproduction requires copulation • Parthenogenesis common • In most species, fertilized eggs have the full diploid number and become female; unfertilized eggs are haploid and become males

8. Integrated Pest Management

9. Natural Enemies of Thrips • PREDATORS Anthocorids, Chrysopids, Nabids, Aeolothrips, Phlaeothrips, predatory mites (Euseius sojanensis) • PARASITES Thripinema (Tylechida: Allantonematidae) • PARASITOIDS Chalcidoidea (Megaphragma sp.) Ceranisus (Eulophidae) • PATHOGENS Fungal pathogens recently reported as important for Scirtothrips dorsalis in India

10. Important Worldwide Predators of Thrips ORDER HEMIPTERA FAMILY ANTHOCORIDAE commonly, pirate bugs GENUS Orius SPECIES insidiosus COMMON NAME Insidious flower bug Photo Stuart Reitz

11. PEPPER Intrinsic capacity of Orius insidiosus to reduce Frankliniella occidentalis populations Photo Joe Funderburk Predator-Prey Ratios 1 : 217 = population suppression 1 : 51 = rapid local extinction Sabelis & Van Rijn (1997) Thrips as Crop Pests. (Lewis, ed.) CAB International, UK

12. thrips larvae Orius Frankliniella occidentalis 50 0.8 fenpropathrin PEPPER 40 30 0.4 20 10 0 0.0 0.8 spinosad 12 per flower 8 Thrips per flower 0.4 4 Pirate bugs 0 0.0 0.8 untreated 12 8 Funderburk, Stavisky & Olson 2000 Environ. Entomol. vol. 29 (2): 376-382 0.4 4 0 0.0 14 17 19 21 24 28 31 3 May & June 1996

13. Commercial Pepper FieldThomas Smith Farms, Greensboro, FL RECOMENDATION FOR PEPPER PRODUCERS CONSERVE ORIUS POPULATIONS BY THE SELECTIVE USE OF TACTICS Courtesy Glades Crop Care, Inc.

14. Aconcague Valley, Chile 120 120 1999-2000 100 100 Annual cycle of abundance of western flower thrips in alfalfa in the southern hemisphere 80 80 60 60 Thrips per 5 terminal shoots in alfalfa 40 40 20 20 0 0 Apr May Jun Jul Aug Sept Oct Nov Dec Jan Feb Mar Apr

15. Dynamics of Frankliniella occidentalis in Alfalfa in Central Chile as Influenced by Pirate Bugs 291 0 Number of total thrips per Orius insidiosus 140 Number of thrips per 5 terminal shoots 13 68 0 81 64 18 16 16 17 Ripa, Rodriguez, Funderburk, & Espinoza, unpublished

16. Species of Thripinema, Nematode Parasites of Thrips • T. nicklewoodi (North America) • T. khrustalevi (Asia, South America) • T. fuscum (North America) • T. aptini (Europe) • T. reniroai (Asia) • Undescribed species (New Zealand) Photo Chris Tipping

17. EFFECTS OF Thripinema PARASITISM ON EGG PRODUCTION OF THRIPS HOST 3 Not parasitized, healthy host 2 1 0 3 Fecundity of Frankliniella fusca (eggs per day) Infected when 3-day-old adult 2 1 0 3 2 Infected when 1-day-old adult 1 0 3 2 Infected when Larvae II 1 0 3 Infected when Larvae I 2 1 0 0 5 10 15 20 25 Age of Adult FemaleThrips (days) Sims, Funderburk & Boucias 2005 J. Nematol.

18. % TSW % parasitized F. fusca F. fusca larval thrips 80 Parasitism nearly prevents mid & late season cycles of TSW 60 Funderburk et al. 2002. Environ. Entomol. 31(3): 558-563. % TSW 40 PEANUTS 20 0 75 80 60 50 % F. fusca parasitized by T. fuscum Thrips per plant Parasitism suppresses thrips mid and late season 40 25 20 0 0 20 May 9 Jun 29 Jun 19 Jul 8 Aug 28 Aug 17 Sept 1999

19. Recommendations for Peanut Producers • Cultivars partially resistant to Tomato spotted wilt virus • Biological control • Planting date • Insecticides that conserve key natural enemies Photo Joe Funderburk Funderburk & Latsha. 2005. Nematodes As Biocontrol Agents. ( Grewal et al. eds.) CAB International, UK

20. TOMATO UV mulch Photo Joe Funderburk

21. ACTIGARD (Syngenta) • Acibenzolar-S-methyl • Substitutes for the natural systemic-acquired-resistance molecule salicylic acid that is essential for activation of systemic acquired resistance • Six applications on tomatoes at two-week intervals beginning at transplanting

22. Recommendations for tomato producers • UV mulch effective in reducing thrips invasion and primary spread of TSWV • Actigard recommended when using UV mulch to reduce sprays of copper and other pesticides that reduce the UV reflectance of the mulch • Insecticides useful in suppressing thrips larvae and secondary spread of TSWV Source Momol et al. 2004. Plant Disease 88(8): 882-890

23. Thrips and Tomato Spotted Wilt • Regulation of vector populations with insecticides is not sustainable producing undesirable environmental and economic consequences • Integrated pest management is effective, environmentally friendly, and sustainable • Management programs developed from knowledge of vector population dynamics and disease epidemiology

24. Chilli Thrips Natural Enemies • Egg Parisitoid • Megaphragma sp. (Chalcidoidea) • 53.2% parasitism on grapes in Japan • Predatory Mite • Euseius sojaensis • 1.4 larvae/hr • 5.4 larvae/day

25. Ornamental Plant Hosts of Concern For the latest information on chilli thrips and ornamental plants, visit http://mrec.ifas.ufl.edu/lso/thripslinks.htm

26. Ornamentals • abamectin (Avid) • acephate (such as Orthene or Orthonex) • acetamiprid (TriStar) • azadirachtin (such as Azatin, Neem oil) (not labeled for thrips) • cyfluthrin (Decathlon, Discus, Bayer Advanced products such as Tree and Shrub Insect Control or Rose and Flower Insect Killer) • disulfoton (such as Di-Syston Systemic Insecticide Granules) • imidacloprid (Marathon, Merit, Discus and the Bayer products listed above) • novaluron (Pedestal) • spinosad (such as Conserve) Materials in yellow would be suitable for use by homeowners if used according to the labeled instructions.

27. Overall Conclusions • Management of S. dorsalis in the landscape requires an integrated approach that includes a detailed understanding of pest biology, natural enemy complexes, and host resistance. • Chemical control options are also available and may be necessary in some cases. • Chemical control options or destruction of plant material is the only option for retail nurseries as long as S. dorsalis remains a regulated pest.

28. Disclaimer The use of trade names in this presentation is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication does not signify our approval to the exclusion of other products of suitable composition. All chemicals should be used in accordance with directions on the manufacturer's label. Use pesticides safely. Read and follow directions on the manufacturer's label.