|Natwick, Eric - UC COOP HOLTVILLE|
|Deeter, Brian - AVENTIS CORP|
Submitted to: Sweetpotato Whitefly Progress Review Proceedings
Publication Type: Proceedings
Publication Acceptance Date: April 1, 2002
Publication Date: June 1, 2002
Technical Abstract: Silverleaf whitefly (SLW) insecticide efficacy research trials were conducted during the cotton seasons of 1997-2000 at the U of CA Desert Res. and Ext. Center in the Imperial Valley, CA to evaluate neonicotinoid insecticides and standard insecticides for control of SLW in cotton. Neonicotinoid insecticidal compounds, acetamiprid, imidacloprid, and thiamethoxam were compared to the standard whitefly insecticide fenpropathrin in a tank mixture with an organophosphate, acephate and compared to a cyclodiene compound endosulfan for control efficacy of whitefly adults, eggs and nymphs. Cotton stands, var. DPL 5415, were established at UC Desert Res. and Ext. Center in March for each year of study for the establishment of SLW insecticide efficacy trials. During 4 years of study, lint yields were not often different between the pyrethroid standard treatment and the neonicotinoid treatments. Treatments resulting in lower numbers of SLW adults, eggs, and nymphs generally produced higher values of seed cotton pounds per acre and lint pounds/acre. Other factors that could influence yield included relative susceptibility of western flower thrips, cotton leafperforator and Empoasca sp. leafhoppers to the various insecticides. Insecticides in these studies vary in their spectra of activity. Danitol®, Orthene® 90S and endosulfan are active against a broad range of cotton insect pests and Assail®, Actara®, and Provado® have narrower ranges of activity. The neonicotinoid insecticides provide SLW control in cotton at levels similar to the pyrethroid plus organophosphate standard Danitol® + Orthene®. The 0.06 lb ai/acre rate of Actara® and the 0.01 lb ai/acre and 0.075 lb ai/acre rates of Assail® 70 WP, and Danitol® + Orthene® maintain similar levels of silverleaf whitefly adult, egg, and nymph throughout the cotton season. The neonicotinoid insecticide, Assail®, and Danitol® plus Orthene® treatments provided the highest levels of control for SLW.