Side effects of conventional and non-conventional insecticides on eggs and larvae of Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) in Argentine.

The objective of this work was to evaluate the effect of two conventional insecticides commonly used in soybean crops of Argentina, endosulfan (Endosulfan 35 Glex, 105 ppm) and cypermethrin (Glextrin 25, 75 ppm) and two insecticides belonging to the new insecticides' generation, methoxyfenozide (Inteprid SC 24%, 144 ppm) and spinosad (Tracer 48%, 120 ppm), on eggs and larvae of Chrysoperla externa (Hagen) by dipping and topical application, respectively, under laboratory conditions. After egg treatment, the percentage of egg hatching, duration of the embryonic period and survival of first-instar larvae were evaluated. In the third-instar larvae assay, the survivals of the larvae and pupae, as well as eggs fertility were recorded. Endosulfan and cypermethrin were highly toxic towards eggs and larvae with mortality rates ranging from 80% to 100%. Toxicity of spinosad was intermediate causing short-term effects, but it did not cause any long-term effects. Methoxyfenozide was harmless to eggs and larvae of C. externa, showing good potential for use in integrated pest management in soybean crops. The selectivity of these insecticides and their inclusion in IPM programs is discussed.