Temperate fruit crops are an important economic activity for growers in southern Brazil. However, several pest species
are associated to apple (
Malus domestica
Borkh.) crops in Brazil. Pesticides are largely used to control them and one way
to change this is to combine selective pesticides and predator insects. The goal of this research was to evaluate the effects
of the abamectin, carbaryl, fenitrothion, methidathion, sulfur, and trichlorfon pesticides on the survival and stage length
of larvae and pupae, adult oviposition from treated larvae, and hatched eggs of two
Chrysoperla externa
(Hagen, 1861)
(Neuroptera: Chrysopidae) populations. The compounds were sprayed on glass plates in accordance with the International
Organization for Biological Control (IOBC) recommendations. First- and second-instar larvae were exposed to pesticide
residues. Carbaryl, fenitrothion, and methidathion caused 100% mortality of first- and second-instar larvae. Changes in
the number of eggs laid by females from first- and second-instar larvae exposed to residues of abamectin and sulfur, or
abamectin, sulfur, and trichlorfon, respectively, were not observed. Only abamectin reduced the number of hatched eggs
laid by females in Bento Gonçalves from treated first-instar larvae. Sulfur reduced the viability of
C. externa eggs in Bento
Gonçalves and Vacaria females from treated second-instar larvae, whereas trichlorfon and abamectin reduced the viability
of eggs in Vacaria females. In conclusion, carbaryl, fenitrothion and methidathion were harmful to
C. externa. Trichlorfon
was harmful to first-instar larvae and slightly harmful to second-instar larvae. Abamectin and sulfur were slightly harmful
to first-instar larvae and harmless to second-instar larvae.
