Sobrevivência e reprodução de Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) alimentada com dietas natural e artificial tratadas com inseticidas

Abstract

Chrysoperla externa is a voracious predator abundant in Brazil, which has been the focus of biological control programs. Biological control companies have registered this agent with the Ministry of Agriculture for use in crops with the presence of whiteflies and aphids. Th release of C. externa in the field faces challenges, among them, the presence of insecticides. Of these, the main ones used are insecticides of the pyrethroids, organophosphates, benzoylures and diamides groups. The aim was to study the survival and reproduction of Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) fed natural and artificial diets treated with insecticides. To evaluate behavioral changes and survival of C. externa when fed diets exposed to insecticides in these groups, Bioassay I was carried out, in which their larvae received aphids exposed to insecticides, in addition to the control treatments M. sacchari (T1) and eggs of Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) (T2), without insecticides, which served as a source of food. In Bioassay II, adults of C. externa received diets composed of a mixture of honey, brewer's yeast and water (T1 control) and honey, brewer's yeast and insecticide syrup for the other treatments. Evaluations of survival, predation, oviposition and emergence of the larvae of C. externa generation F1 were made every two days throughout their life cycle. Clopirifós was non-selective and eliminated larvae and adults between 0 and 2 days. The Lufenuron did not allow the passage of C. externa larvae from instar 2 to 3, resulting in their death within 10 days. The survival and predation results for the treatment containing chlorantraniliprole were statistically equal to the controls T1 and T2 during the larval stage, but eliminated the adults exposed to the diet containing these insecticides within 12 days. The bifenthrin reduced predation by C. externa larvae (Bioassay I), but survival did not differ statistically in relation to controls for Bioassays I and II. Lufenuron and bifenthrin decreased the mean oviposition, however, among the treatments containing insecticides, there was emergence of larvae of the F1 generation of C. externa only in the treatment with bifenthrin (Bioassay II). It was concluded that the insecticides (Table 1) reduced the predatory capacity of C. externa larvae, with the exception of chlorantraniliprole. The survival, oviposition and emergence of C. externa larvae of the F1 generation also presented lower averages compared to the control. The active ingredient bifenthrin was less harmful than the other insecticides tested; however, it is necessary to evaluate its effects through direct exposures before safely recommending it in integrated pest management.