Resistance management for Bemisia tabaci
Studies have been carried out in Israel on resistance management of insect growth regulators (buprofezin and pyriproxyfen) used against Bemisia tabaci (EPPO A2 quarantine pest). Insecticide resistance has been monitored during 1991-1992 in a rose glasshouse and in adjacent cotton fields located in western Negev. In the glasshouses, no resistance management was followed (two applications of buprofezin or three consecutive applications of pyriproxyfen, whereas in cotton field an insecticide resistance management was followed (pyriproxyfen was applied once a year). Whiteflies collected were then exposed to a series of concentrations of buprofezin and pyriproxyfen. In the glasshouse, results indicated a 4-fold increase tolerance to buprofezin after two successive applications of this compound, and showed that a relatively high level of resistance to pyriproxyfen was recorded after three successive applications. In cotton fields with one application of pyriproxyfen, however, the susceptibility of B. tabaci was not appreciably altered. The authors point out that their study has demonstrated the rapid development of resistance in B. tabaci to pyriproxyfen in a glasshouse and stressed the need for insecticide resistance management. They concluded that to prevent the development of resistance to buprofezin and pyriproxyfen, their use should be limited to one application per season.
Sources
Horowitz, A.R.; Ishaaya; I. (1994) Managing resistance to insect growth regulators in the sweet potato whitefly (Homoptera: Aleyrodidae).
Journal of Economic Entomology, 87 (4), 866-871.