Seletividade de acaricidas utilizados em cafeeiro para larvas de crisopídeos

Abstract

Green lacewings are commonly found in coffee agroecosystems feeding on several pests of economic importance. The objective of this study was to evaluate the selectivity of acaricides used in coffee crop to Chrysoperla externa (Hagen, 1861). The treatments consisted of control (water), spirodiclofen (0.12 g a.i./L), fenpropathrin (0.15 and 0.30 g a.i./L), sulphur (4.0 and 8.0 g a.i./L) and abamectin (0.0067 and 0.0225 g a.i./L). The products were sprayed directly on first, second and third-instar larvae of C. externa, using a Potter spray tower. Duration of instar, survival of larvae and pupae and viability of eggs produced by the adults emerged from the treated larvae were evaluated. The pesticides were classified into toxicity classes. Fenpropathrin was toxic and spirodiclofen and abamectin were moderately toxic, requiring further studies under greenhouse and field conditions to confirm or not their toxicities. Because of the low toxicity of sulphur to the predator C. externa, it can be recommended for coffee pest management programs in order to combine chemical and biological control using this Chrysopidae species.