[Use of insecticides on citrus in Hermosillo coast, Sonora Mexico]

Inglés. The use of insecticides on citrus tree in Hermosillo Coast was analyzed, from 1985-1989. The analysis was based upon the selection pressure generated by the insecticides on the insect pest population. Insecticides were grouped according to the mechanisms of resistance they select for, and these groups were refeered as toxicological groups. Results obtained showed that the highest selection pressure was produced by insecticides beloging to the aliphatic dimethyl phosphates (e.g.dimethoate), heterocyclic dimethyl phosphates (e.g.metidathion), chlorinated DDT (e.g.dicofol) and chlorinated cyclodienes (e.g.endosulfan). This suggests that several mechanisms of resistance have been selected simultaneously including glutathione transferase, esterases and mixed function oxidases. It was also detected that the number of toxicological groups used in citrus has increased in the area.

Español; castellano. Se analizo el uso de insecticidas en los citricos de la Costa de Hermosillo durante el periodo de 1985 a 1988. El analisis se baso en la presion de seleccion ejercida por los insecticidas en la poblacion de insectos plaga. Los insecticidas se agruparon de acuerdo a los mecanismos de resistencia que seleccionan, a los cuales se les conoce como grupos toxicologicos. Los resultados obtenidos muestran que la mayor presion de seleccion fue producida por insecticidas pertenecientes al grupo de fosforados alifaticos dimetilicos (dimetoato), fosforados heterociclicos dimetilicos (metidation), organoclorados del DDT (dicofol) y organoclorados ciclodienos (endosulfan). Esto indica que varios mecanismos de resistencia se estan seleccionando simultaneamente, incluyendo glutation transferasa, esterasas y oxidasas en insecticidas de funcion mixta. Tambien se encontro que el numero de grupos usados en citricos se ha incrementado en la region.