The physiological action of the insecticides trichlorfon, triflumuron, endosulfan, fenpropathrin, chlorpiryfos, tebufenozide and esfenvalerate to 2nd-instar larvae of Chrysoperla externa (Hagen) and subsequent effects on 3rd-instar larvae, pupae and adults were evaluated. The bioassays were carried out under greenhouse conditions. The effect on larvae fed on eggs of Anagasta kuehniella (Zeller) treated with the insecticides was evaluated, as well as the contact effect on 2nd-instar larvae kept on sprayed cotton plants. The survival percentage of individuals in the second- and 3rd-instar and in the pupae stage was determined. For adults, the daily and total production of eggs during 30 days, the viability and the fertility of eggs were evaluated. Endosulfan, tebufenozide and esfenvalerate were selective to 2nd-instar larvae by contact on sprayed plants as well as by suction of treated eggs. For 3rd-instar larvae, neither endosulfan, tebufenozide, esfenvalerate nor triflumuron were harmful. The survival of pupae from treated 2nd-instar larvae with fenpropathrin and tebufenozide was not affected. Trichlorfon, fenpropathrin and tebufenozide caused no reduction in the total number of eggs produced by females derived from 2nd-instar larvae fed with treated eggs of A. kuehniella. Females originated from larvae that kept contact with sprayed cotton plants with esfenvalerate, had no significant reduction in the total egg production. Although tebufenozide affected the reproductive traits of C. externa, it can be recommended for controlling the pests on cotton crop in association with inundative releases of this predator.
Selectivity; green lacewing; pesticide
