Dale Gelman
My research focuses on the use of parasitic insects as biocontrol agents and the development of biopesticides to control crop pests. Of special interest are greenhouse and silverleaf whiteflies which attack more than 500 different species of plants, including food (tomatoes, potatoes, cantaloupes, squash and greenbeans), fiber (cotton) and ornamental (hibiscus and poinsettia) plants. Closely related to aphids and plant hoppers, whiteflies feed on plant fluid (phloem) causing plant abnormalities, transmit viruses which cause serious diseases in plants, and produce honeydew which serves as an excellent growth medium for sooty mold. Integrated pest management programs for control of whiteflies include the use of chemical pesticides, biopesticides such as insect growth regulators, and the release of tiny wasps that parasitize whiteflies. These parasitic wasps manipulate their host insect's physiology and induce developmental arrest in the host insect. I study the physiology, behavior and structure of parasites and their target/host insect for the purpose of: 1) providing information necessary to rear large numbers of whitefly-specific parasitic wasps for release in the field and in greenhouse environments, 2) contribute to the development of new biopesticides through increased understanding of the methods used by parasites to inhibit the growth and maturation of the host insect, and by identifying and characterizing other insect development suppressor molecules. If whitefly-specific wasp parasites could be grown in large numbers and released in the field and/or if new, effective biopesticides could be developed, the need for chemical pesticides to control whiteflies would be reduced.
Read some more about this project in the Agricultural Research Magazine.
Recent Publications:
- Gelman, D. B., Reed, D. A., and Beckage, N. E. "Manipulation of fifth-instar host (Manduca sexta) ecdysteroid levels by the parasitoid wasp Cotesia congregata." J. Insect Physiol. 44: 833-843. 1998.
- Kelly, T. J., Gelman, D. B., Reed, D. A., and Beckage, N. E. "Effects of parasitization by Cotesia congregata on the brain-prothoracic gland axis of its host, Manduca sexta." J. Insect Physiol. 44: 323-332. 1998.
- Gelman, D. B., Kelly, T. J., and Coudron, T. A. " Mode of action of the venom of the ectoparasitic wasp, Euplectrus comstockii, in causing developmental arrest in the European corn borer, Ostrinia nubilalis." Invertebrate Neuroscience 3: 231-238. 1997.
- Gelman, D. B., Kelly, T. J., Reed, D. A. and Beckage, N. E. "Synthesis/release of ecdysteroids by Cotesia congregata, a parasitoid wasp of the tobacco hornworm, Manduca sexta." Arch. Insect Biochem. Physiol. 40: 17-29. 1999.
- Smagghe, G., Gelman, D. B. and Tirry, L. "In vivo and in vitro effects of tebufenozide and 20-hydroxyecdysone on chitin synthesis." Arch. Insect Biochem. Physiol. 41: 33-41. 1999.
- Gelman, D. B., Rojas, M. G., Kelly, T. J., Hu, J. S. and Bell, R. A. "Ecdysteroid and amino acid content of eggs of the Colorado potato beetle, Leptinotarsa decemlineata." Arch. Insect Biochem. Physiol. 44: 172-182. 2000.
- Hu, J. S., Gelman, D. B. and Bell, R. A. "In vitro rearing of Edovum puttleri, an egg parasitoid of the Colorado potato beetle, from egg to pupal stage in artificial diets devoid of insect sources: Effects of dietary amino acid and carbohydrate levels." Biocontrol. 46: 43-60. 2001.
- Gelman, D. B., Bell, R. A., Liska L. J., and Hu J. S. "Artificial diets for rearing the Colorado potato beetle, Leptinotarsa decemlineata Say (Col.: Chrysomelidae)." J. Insect Sci. 1: Article #7. 2001. http://www.insectscience.org/1.7/
- Gelman, D. B., Blackburn M. B. and Hu J. S. "Timing and ecdysteroid regulation of the molt in penultimate and last instar greenhouse whiteflies (Trialeurodes vaporariorum)." J. Insect Physiol. 48(1): 63-73. 2002.
- Hu J. S., Gelman, D. B. and Blackburn M. B. "Growth and development of Encarsia formosa (Hymenoptera: Aphelindae) in the greenhouse whitefly, Trialeurodes vaporariorum (Homoptera: Aleyrodidae): Effect of host age." Arch. Insect Biochem. Physiol. 49: 125-136. 2002.
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