Nicotine sulfate and resmethrin, applied at recommended rates, were less toxic to adults and larvae of Encarsia formosa than were endosulfan, malathion, or naled. Adult parasites were killed by contact with any of the 5 chemicals. Endosulfan and malathion left residues toxic to adult E. formosa for 2 to 3 weeks; malathion and naled killed many 10- to 15-day-old parasite larvae. The potential uses of nicotine sulfate and resmethrin were shown in theoretical models for integrated control of greenhouse whitefly.
Received for publication June 6, 1975. Contribution No. 561, Department of Horticulture and Forestry, Kansas Agricultural Experiment Station, Kansas State University, Manhattan.
Former Research Assistant. Present address: Agri. Research and Education Center, University of Florida, Bradenton, Florida.