In the San Joaquin Valley, cotton aphids have become resistant to commonly used pesticides
California Agriculture 46(4):4-7. DOI: 10.3733/ca.v046n04p4.
Laboratory bioassays have demonstrated that cotton aphids are resistant to organophosphate pesticides in many areas Of the Sari Joaquin Valley. Many of the aphids are resistant before they reach newly emerged cotton; their resistance tends to decline at the end of the season. The best management strategy: Avoid using pesticides in spring when they are least effective and natural enemies are abundant, and use pesticides at the end of the season to prevent sticky cotton bolls.
E. E. Grafton-Cardwell is an Extension IPM Specialist and Assistant Research Entomologist in the Department of Entomology, UC Riverside, and is stationed at the UC Kearney Agricultural Center; T. F. Leigh is an Entomologist in the Department of Entomology, UC Davis; W. J. Bentley is an Entomology Farm Advisor for Kern County; P. B. Goodell is an area IPM Specialist for the South Central California Region, Cooperative Extension.
The authors thank Jeffrey Granett and the Department of Entomology at UC Davis for use of a laboratoy to conduct this research; John DeBenedictis, Lijie Jia, Yuling Ouyang, and Stacy Vehrs for technical assistance; and Dow Chemical, Mobay, Dupont, and FMC corporations for providing insecticides. This project was supported in part by funds from the Cotton Pest Control Board and Eke Western Regional Pesticide Impact Assessment Program.