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Entomology: Peter C. Ellsworth

Specialist, IPM

Located at Maricopa Agricultural Center.

B.S., University of New Hampshire
M.S., University of Missouri
Ph.D., North Carolina State University (all in entomology).

I have broad interests in insect-crop interactions and applied insect ecology with particular emphasis on those aspects, which may be exploited for sound ecological and economical pest management. My responsibilities are to develop science-based solutions for integrated pest management through applied ecological investigations and organized outreach programs of Cooperative Extension, with principal focus on Bemisia tabaci, Lygus hesperus and Pectinophora gossypiella in the cotton agroecosystem, other field crops, and new crops as well as in cross-commodity interactions. In addition, I am interested in insect phenology, diapause, insect-water relations, predictive modeling, pest biology, sampling, thresholds, and damage dynamics.

As Director of the multi-disciplinary Arizona Pest Management Center, I help manage our institution's NIFA Extension IPM grant, serve as our state's federal IPM Coordinator and Pesticide Coordinator, and oversee and help organize teams of research and extension faculty for the betterment of the science and application of IPM in Arizona.

Selected publications

Crowder, D.W., T.J. Dennehy, C. Ellers-Kirk, C.M. Yafuso, P.C. Ellsworth, B.E. Tabashnik & Y. Carrière, 2007. Field Evaluation of resistance to pyriproxyfen in Bemisia tabaci (B Biotype), Journal of Economic Entomology 100: 1650-1656

Crowder, D.W., P.C. Ellsworth, B.E. Tabashnik & Y. Carrière, 2008. Effects of operational factors on evolution of resistance to pyriproxyfen in the sweetpotato whitefly (Hemiptera: Aleyrodidae). Environmental Entomology, 37(6): 1514-1524.

Harringotn, J., Byrne, P.F.m Peairs, F.B., Nissen, S.J., Westra, P., P.C. Ellsworth, Fournier, A., Mallory-Smith, C.A., Zemetra, R.S., Henry, W.B. (2009). Perceived consequences of herbicide-tolerant and insect-resistant crops on integrated pest management strategies in the western United States: Results of an online survey. AgBipForum, 12(3&4), 412-421, or at or at

Naranjo, S.E. & P.C. Ellsworth. 2009. The contribution of conservation biological control to integrated management of Bemisia tabaci in cotton. Biological Control, 51(3): 458-470.

Naranjo, S.E. & P.C. Ellsworth. 2009. 50 years of the integrated control concept: moving the model and implementation forward in Arizona. Pest Management Science, 65: 1267-1286.

Horowitz AR, Ellsworth PC and I. Ishaaya I. 2009, Biorational pest control: an overview, In Biorational Control of Arthropod Pests: Application and Resistance Management, ed. by Ishaaya I and Horowitz AR, Springer.

Naranjo, S.E. and P.C. Ellsworth. 2010. Fourteen years of Bt cotton advances IPM in Arizona. Southwest. Entomol. 35: 437-444.

Richards, T.J., P.C. Ellsworth, R. Tronstad and S. E. Naranjo, 2010. Market-based instruments for the optimal control of invasive species: Bemisia tabaci in Arizona. J. Agric. Resource Econ. 35: 349-367.

Tabashnik, B.E., M.S. Sisterson, P.C. Ellsworth, T.J. Dennehy, L. Antilla, L. Liesner, M. Whitlow, R. T Staten, J. A. Fabrick, G. C. Unnithan, A. J. Yelich, C. Ellers-Kirk, V. S. Harpold, X. Li and Y. Carrière. 2010. Suppressing resistance to Bt cotton with sterile insect releases. Nature Biotechnology: 28(12): 1304-1307 (+ online methods & supplementary information, 10 pp.).

Crowder DW, Carrière Y, Tabashnik BE, Ellsworth PC, Dennehy TJ. 2006. Modeling evolution of resistance to pyriproxyfen by the sweetpotato whitefly (Homoptera : Aleyrodidae). Journal of Economic Entomology 99 (4): 1396-1406.

Carrière Y, Ellsworth PC, Dutilleul P, Ellers-Kirk C, Barkley V, Antilla L. 2006. A GIS-based approach for areawide pest management: the scales of Lygus hesperus movements to cotton from alfalfa, weeds, and cotton. Entomologia Experimentalis et Applicata 118 (3): 203-210.

Naranjo SE, Ellsworth PC. 2005. Mortality dynamics and population regulation in Bemisia tabaci. Entomologia Experimentalis et Applicata 116 (2): 93-108.

Ellsworth, P.C. and Barkley, V. 2005. Transitioning Lygus chemical controls to more selective options for Arizona Cotton. pp. 165-178. In Cotton, A College of Agriculture Report, Series P-142. University of Arizona, Tucson.

Naranjo SE, Ellsworth PC, Hagler JR. 2004. Conservation of natural enemies in cotton: role of insect growth regulators in management of Bemisia tabaci. Biological Control 30 (1): 52-72.

Naranjo SE, Hagler JR, Ellsworth PC. 2003. Improved conservation of natural enemies with selective management systems for Bemisia tabaci (Homoptera : Aleyrodidae) in cotton. Biocontrol Science and Technology 13 (6): 571-587.

Palumbo, J.C., P.C. Ellsworth, T.J. Dennehy, and R.L. Nichols. 2003. Cross-Commodity Guidelines for Neonicotinoid Insecticides in Arizona. IPM Series 17. Publ. No. AZ1319. University of Arizona, College of Agriculture and Life Sciences, Cooperative Extension, Tucson, Arizona. 4 pp.

Naranjo SE, Ellsworth PC, Chu CC, Henneberry TJ. 2002. Conservation of predatory arthropods in cotton: Role of action thresholds for Bemisia tabaci (Homoptera : Aleyrodidae). Journal of Economic Entomology 95 (4): 682-691.

Ellsworth PC, Martinez-Carrillo JL. 2001. IPM for Bemisia tabaci: a case study from North America. Crop Protection 20 (9): 853-869.

Naranjo SE, Ellsworth PC, Chu CC, Henneberry TJ, Riley DG, Watson TF, Nichols RL. 1998. Action thresholds for the management of Bemisia tabaci (Homoptera : Aleyrodidae) in cotton. Journal of Economic Entomology 91 (6): 1415-1426.

Hentz MG, Ellsworth PC, Naranjo SE, Watson TF. 1998. Development, longevity, and fecundity of Chelonus curvimaculatus (Hymenoptera : Braconidae), an egg-larval parasitoid of pink bollworm (Lepidoptera : Gelechiidae). Environmental Entomology 27 (2): 443-449.

Naranjo SE, Diehl JW, Ellsworth PC. 1997. Sampling whiteflies in cotton: Validation and analysis of enumerative and binomial plans. Environmental Entomology 26 (4): 777-788.

Naranjo, S.E., J.W. Diehl & P.C. Ellsworth. 1997. Sampling whiteflies in cotton: Validation and analysis of numerical and binomial models. Environmental Entomology 26: 777-788.

Hentz, M.E., P.C. Ellsworth & S.E. Naranjo. 1997. Biology and morphology of Chelonus sp. nr. curvimaculatus (Hymenoptera: Braconidae) as a parasitoid of Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae). Annals of the Entomological Society of America.

Ellsworth, P.C., J.W. Diehl & S.E. Husman. 1996. "Development of integrated pest management infrastructure: A community-based action program for whitefly management." In D. Gerling, ed., Bemisia 1995: Taxonomy, biology, damage, control and management. pp. 681-693.

Norman, J.W., Jr., D.G. Riley, P.A. Stansley, P.C. Ellsworth & N.C. Toscano. 1996. Management of Silverleaf Whitefly: A Comprehensive Manual on the Biology, Economic Impact and Control Tactics. College Station, TX. 22 pp.

Ellsworth, P.C., J.W. Diehl & S.E. Naranjo. 1996. Sampling Sweetpotato Whitefly Nymphs in Cotton. IPM Series No. 6. The University of Arizona, Cooperative Extension. Publication #196006. Tucson, AZ. 2 pp.

Department of Entomology at the University of Arizona
Forbes 410, PO Box 210036, Tucson, AZ 85721-0036
Phone: (520) 621-1151 • Fax: (520) 621-1150 • E-mail:

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College of Agriculture & Life Sciences Arizona Cooperative Extension