Dr. George P. Opit, Assistant Professor of Stored Product/Post Harvest Pest Management

B.S., Makerere University, 1986 M.P.M., Simon Fraser University, 1995 Ph.D., Kansas State University, 2003 george.opit@okstate.edu

Links:

Stored-product psocid identification website

Research:

Broadly my research interests are in integrated pest management and biological control of arthropod pests. Specifically my research interests are centered on investigating the biology, behavior, and population dynamics of stored-product arthropod pests and their natural enemies and to use the information acquired to optimize pest management.

Over the last 15 years, psocids (order Psocoptera) have emerged worldwide as serious stored-product pests. Part of my research deals with identifying psocids associated with grain storage, handling, and processing facilities and product warehouses in the U.S. I am also conducting studies on the biology, behavior, and population dynamics of psocid species that are a potential threat to U.S. agriculture.

Refereed Journal Articles:

Athanassiou, C.G., F. H. Arthur, G.P. Opit, and J. E. Throne. 2009. Insecticidal effect of diatomaceous earth against three species of stored-product psocids on maize, rice, and wheat. Journal of Economic Entomology 102: 1673-1680.

Flinn, P.W., G.P. Opit, and J.E. Throne. 2009. Predicting stored grain insect population densities using an electronic grain probe trap. Journal of Economic Entomology 102: 1696-1704.

Opit, G.P., J.E. Throne, and P.W. Flinn. 2009. Sampling plans for the psocids Liposcelis entomophila and Liposcelis decolor (Psocoptera: Liposcelididae) in steel bins containing wheat. Journal of Economic Entomology 102: 1714-1722.

Opit, G.P. and J.E. Throne. 2009. Population growth and development of the psocid Liposcelis brunnea Motschulsky (Psocoptera: Liposcelididae) at constant temperatures and relative humidities. Journal of Economic Entomology 102: 1360-1368.

Opit, G.P., J.E. Throne, and P. W. Flinn. 2009. Temporospatial distribution of the psocids Liposcelis entomophila (Enderlein) and L. decolor (Pearman) (Psocoptera: Liposcelididae) in steel bins containing wheat. Journal of Economic Entomology 102: 1369-1376.

Opit, G.P., J.E. Throne, and P. W. Flinn. 2009. Evaluation of five sampling methods for Liposcelis entomophila (Enderlein) and L. decolor (Pearman) (Psocoptera: Liposcelididae) in steel bins containing wheat. Journal of Economic Entomology 102: 1377-1382.

Opit, G. P., J. Perret, K. Holt, J. R. Nechols, D. C. Margolies, and K. A. Williams. 2009. Comparing Chemical and Biological Control Strategies for Twospotted Spider Mites (Acari: Tetranychidae) in Commercial Greenhouse Production of Bedding Plants. Journal of Economic Entomology 102: 336-346.

Guedes, R.N.C., K.Y. Zhu, G.P. Opit, and J.E. Throne. 2008. Differential heat shock tolerance and expression of heat-inducible proteins in two stored-product psocids. Journal of Economic Entomology 101: 1974-1982.

Guedes, R.N.C., J. F. Campbell, F. H. Arthur, K. Y. Zhu, G. P. Opit, and J. E. Throne. 2008. Acute lethal and behavioral sublethal responses of two stored-product psocids to surface insecticides. Pest Management Science 64: 1314-1322.

Opit, G.P. and J.E. Throne. 2008. Effects of diet on population growth of the psocids Lepinotus reticulatus and Liposcelis entomophila. Journal of Economic Entomology 101: 616-622.

Opit, G.P. and J.E. Throne. 2008. Population growth and development of the psocid Lepinotus reticulatus at constant temperatures and relative humidities. Journal of Economic Entomology 101: 605-615.

Opit, G.P., and J.E. Throne. 2007. Influence of maternal age on the fitness of progeny in the rice weevil, Sitophilus oryzae (Coleoptera: Curculionidae). Environ. Entomol. 36: 83-89.

Chen, Y., G.P. Opit, V.M. Jonas, K.A. Williams, J.R. Nechols, and D.C. Margolies. 2007. Twospotted Spider Mite Population Level, Distribution, and Damage on Ivy Geranium in Response to Different Nitrogen and Phosphorus Fertilization Regimes. Journal of Economic Entomology 100:1821-1830.

Holt, K.M., G.P. Opit, J.R. Nechols, D.C. Margolies, and K.A. Williams. 2007. Comparing Chemical and Biological Control Strategies for Twospotted Spider Mites in Mixed Production of Ivy Geranium and Impatiens. HortTechnology 17: 279-401.

Holt, K. M., G. P. Opit, J. R. Nechols and D. C. Margolies. 2006. Testing for non-target effects of spinosad on twospotted spider mites and their predator Phytoseiulus persimilis under greenhouse conditions. Exp. Appl. Acarol. 38: 141-149.

Opit, G.P., G.K. Fitch, D.C. Margolies, J.R. Nechols, and K.A. Williams. 2006. Overhead and drip tube irrigation affect twospotted spider mites and their biological control by a predatory mite on impatiens. HortScience 41: 691-694.

Weaver, D.K., G.P. Opit, L.J. Mason, and J.E. Throne. 2006. Gravimetric method for determining stage of an obligate internally feeding stored-product insect pest, the cowpea weevil. Environ. Entomol. 35: 1483-1490.

Alatawi, F. J, G. P. Opit, D. C. Margolies, and J. R. Nechols. 2005. Within-plant distribution of two-spotted spider mites, Tetranychus urticae Koch (Acari: Tetranychidae), on impatiens: development of a presence-absence sampling plan. J. Econ. Entomol. 98: 1040-1047.

Opit, G. P., J. R. Nechols, D. C. Margolies, and K. A. Williams. 2005. Survival, horizontal distribution, and economics of releasing predatory mites (Acari: Phytoseiidae) using mechanical blowers. Biol. Control 33: 344-351.

Opit, G. P., Y. Chen, K. A. Williams, J. R. Nechols, and D. C. Margolies. 2005. Plant age, fertilization, and biological control affect appearance of twospotted spider mite damage on ivy geranium: development of action threshold. J. Am. Soc. Hortic. Sci. 130: 159-166.

Opit, G. P., J. R. Nechols, and D. C. Margolies. 2004. Biological control of twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), using Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseidae) on ivy geranium: assessment of predator release ratios. Biol. Control 29: 445-452.

Opit, G. P., D. C. Margolies, and J. R. Nechols. 2003. Within-plant distribution of twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), on ivy geranium: Development of a presence-absence sampling plan. J. Econ. Entomol. 96: 482-488.

Opit, G. P., V. M. Jonas, K. A. Williams, D. C. Margolies, and R. J. Nechols. 2002. Effects of cultivar and irrigation management on population growth of the twospotted spider mite Tetranychus urticae on greenhouse ivy geranium. Exp. Appl. Acarol. 25: 849-857.

Gillespie, D. R., G. P. Opit, and B. Roitberg. 2000. The effects of temperature and relative humidity on development, reproduction and predation in Feltiella acarisuga (Vallot)(Diptera: Cecidomyiidae). Biol. Control 17: 132-138.

Opit, G. P., B. Roitberg, and D. R. Gillespie. 1997. The functional response and prey preference of Feltiella acarisuga (Diptera: Cecidomyiidae) for two of its prey: male and female twospotted spider mites, Tetranychus urticae Koch (Acari: Tetranychiidae). Can. Entomol. 129: 221-227.

Opit, G. P., D. R. Gillespie, and R. Costello. 1997. The life cycle and management of Echinothrips americanus (Thysanoptera: Thripidae). J. Ent. Soc. Brit. Col. 94: 3-6.

Other Publications:

Throne, J.E., G.P. Opit, and P.W. Flinn. 2008. Comparison of methods for sampling psocids in stored wheat. In S. Navarro, C. Adler, and L.S. Hansen (eds.), Proceedings of the International Organisation for Biological and Integrated Control West Palaearctic Region Section Working Group on Integrated Protection of Stored Products, Poznan, Poland, 20-23 August 2007. IOBC/WPRS Bulletin 40: 67-74.

Flinn, P.W., G.P. Opit, and J.E. Throne. 2006. Integrating the Stored Grain Advisor Pro expert system with an automated electronic grain probe trapping system. Proceedings of the 9th International Working Conference on Stored Product Protection. Brazilian Post-harvest Association-ABRAPOS, P. 408-413.

Throne, J.E., G.P. Opit, and P.W. Flinn. 2006. Seasonal distribution of psocids in stored wheat. Proceedings of the 9th International Working Conference on Stored Product Protection. Brazilian Post-harvest Association - ABRAPOS, p. 1095-1103.

Opit, G., J. Nechols, K. Williams, and D. Margolies. 2006. Blow thrips and mites away. Greenhouse Grower 24: 8-12.

Chen, Y. and G. Opit. 2005. Managing twospotted spider mite. Ornamental Outlook July 2005, 31-32.

Opit, G., J. Nechols, K. A. Williams, Y. Chen, and D. Margolies. 2005. Two pests to be on the lookout for - scouting helps control thrips, twospotted spider mites. GMPRO 25: 46-52.

Opit, G. P., K. Williams, D. Margolies, J. Nechols, and Y. Chen. 2003. Look before you leap - managing an infestation of twospotted spider mites on ivy geranium. Greenhouse Business 9: 25-26.

Gillespie, D.R., McGregor, R.R. and Opit, G. 1999. Evaluation of Cotesia marginiventris (Cresson) (Hymenoptera: Braconidae) for biological control of Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae) in greenhouse vegetable crops in British Columbia. International Organization for Biological Control, West Palearctic Regional Section, Integrated Control in Glasshouses. Brest, France, May 1999, Bulletin. 22 (1): 89-92.

Gillespie, D.R., Opit, G., McGregor, R., et al. 1998. Recommendations for the use of parasitic wasp Cotesia marginiventis (Hymenoptera: Braconidae) for biological control of cabbage looper Trischoplusia ni. Pacific Agriculture Research Center, Agassiz, BC, Canada. Technical Report #142.

Gillespie, D.R., Opit, G., McGregor, R., et al. 1997. Use of Cotesia marginiventris (Cresson) (Hymenoptera: Braconidae) for biological control of cabbage loopers, Trichoplusia ni (Lepidoptera: Noctuidae) in greenhouse vegetable crops in British Columbia. Pacific Agriculture Research Center, Agassiz, BC, Canada. Technical Report #141.

Opit, G. P., B. Roitberg, and D. R. Gillespie. 1997. The functional response and prey preference of Feltiella acarisuga (Diptera: Cecidomyiidae) for two of its prey: male and female twospotted spider mites, Tetranychus urticae Koch (Acari: Tetranychiidae). Can. Entomol. 129: 221-227.

Gillespie, D. R., D. M. J. Quiring, G. P. Opit, and M. Greenwood. 1994. Biological control of two-spotted spider mites on greenhouse tomato. Pacific Agriculture Research Center, Agassiz, BC, Canada. Technical Report #105.