Influence of Insecticides on Useful Entomofauna in Corn Crops

Abstract

Goal. of research is to specify species composition of coccinellids of corn agrocenosis, to define insecticides influence on useful entomofauna, to estimate the profitability level of used preparation.
 Methods. Are the following: field accounting of insects in corn crops in accordance with the generally accepted methodology; experiment on the influence of insecticides on useful entomofauna in corn. Laboratory method that means identification of species composition of ladybirds.
 Results. Specified species composition of coccinellids in present conditions on corn crops. Educed six species of ladybirds, among them Coccinella septempunctata Linnaeus, 1758 was marked as dominant species, while Propylea quatuordecimpunctata Linnaeus, 1758 as subdominant species. Presented mean quantity of coccinellids, green lacewings, syrphids on the 3rd, 7th, 14th and 21st days after spraying of insecticides on corn. Specified correlation of coccinellids species before and after insecticide application. Presented correlation of entomophages (ladybirds, green lacewings, syrphids) on corn crops. Determined technical and economic efficiency after spraying of corn with insecticides Ampligo 150 ZC (Chlorantraniliprole, 100g/l+Lambda-Cyhalothrin, 50g/l), Belt 480 SC (Flubendiamide, 480 g/l), Coragen 20 SC (Chlorantraniliprole, 200 g/l).
 Conclusions. After insecticides application the highest mean quantity of coccinellids was observed in case of Coragen 20 SC — 2,4 exemplars/m2, after Ampligo 150 ZC it was 0,4 exemplars/m2, after Belt 480 SC — 0,7 exemplars/m2. The mean quantity of green lacewings and syrphids was low for all variants. The least toxic effect on quantity of entomophages had an insecticide Coragen 20 SC. The percentage of dead insects after its usage was the following: for imago of coccinellids — 43.4%, larvae — 79.5%, pupas — 54.2%; green lacewings — 68.2%, syrphids — 75.0%. Spraying of preparation Coragen 20 SC provided the level of profitability 440.16%, whereas profitability after Ampligo 150 ZC was 289.33%, after Belt 480 SC — 126.81%.