Seletividade e resposta comportamental a acaricidas em Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae)

Abstract

The coconut mite, Aceria guerreronis Keifer, is a major pest of this palm in the world. The use of acaricides is the most common control method for controling A. guerreronis, however periodical applications are required in short time intervals. The predatory mites belonging to the families Phytoseiidae represent an alternative to reducing acaricide use in that culture. Among the predatory mites, Neoseiulus baraki (Athias-Henriot) has been often reported in association with that eriophyid. The objective of this study was to compare the lethality of acaricides between A. guerrernis and N. baraki; to study the effect of these products on the survival, instantaneous rate of increase and behavior of the predator, besides of the potential synergism to fenpyroximate against the predator. The LC50 of azadirachtin, chlorfenapyr and fenpyroximate was higher for N. baraki compared to A. guerreronis. Theses acaricides did not affect the instantaneous rate of increase of the predator. The highest synergism was observed for piperonyl butoxide, indicating that tolerance of N. baraki to fenpyroximate is probably related to cytochrome P450 monooxygenase activities. Chlorfenapyr and azadirachtin caused lower reduction in survival time compared to other products. The distance walked, ambulatory time, walking velocity and number of stops of the predator were not affected when exposed to fenpyroximate, chlorfenapyr and chlorpyrifos. Azadirachtin and chlorpyrifos repelled the predator and all acaricides caused irritability in the predator, except abamectin. Among the acaricides, chlorfenapyr and fenpyroximate are the most suitable for managing A. guerreronis.