Effect of some insecticides on the control of the Caterpillar Ascia monuste orseis (Godart, 1819) (Lepidoptera: Pieridae) and on the activity of the predator Allograpta sp. (Diptera: Syrphldae) in brassicaceae

Author(s)

Fabiane Abreu Drummond

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2002-07-19
• Advisor: Octavio Nakano

Abstract

The Brassicaceae are frequently attacked by several pests, standing out Ascia monuste orseis (Godart, 1819) (Lepidoptera: Pieridae), whose Caterpillars consumes the leaves with such voracity that can take to the destruction of the crop. Together with this pest it is common the occurrence of the aphids Brevicoryne brassicae and Lipaphis erysimi (Hemiptera: Aphididae) which are frequent1y attacked by the predator Allograpta sp. (Diptera: Syrphidae). This predator is commonly found feeding on aphids, which cause appreciable damage in brassicaceae (cabbage, cauliflower, broccolis, etc.), because leaves and/or flowers of brassicaceae are used for consumption; the use of some insecticide should be avoided. Besides the fact that insecticides leave toxic residues to the human being, they constitute sources of environmental pollution. The present work had as objective: 1) to test the effects of the application of some insecticides, considered slight1y toxic to the mammals, in appropriate dosages, on the Caterpillars of Ascia monuste orseis and on the predator of aphids, Allograpta sp.; 2) to observe which products can affect the predator Allograpta sp., generally present in the crop among the populations of aphids. The bioassay was realized in the Entomology Department in the College of Agriculture "Luiz de Queiroz" University of São Paulo. Initially, the biology and creation of the predator, aphids and caterpillars, were developed in laboratory conditions. The larvas and Caterpillars were contaminated by selectivity insecticides or slight toxic to mammals. The products utilized were: abamectin, diflubenzuron, azadirachtin, methoxyfenozide, tebufenozide and methoprene using the half of the recommended dose. Abamectin, diflubenzuron and azadirachtin were effective in the controI of the pest and, at the same time, selective to the predator. It was observed that, in the treatment with abamectin, there was larger consumption of aphids by the predator, during its larval development. Abamectin was considered the best treatment, because it increased the predation and also to the life cyc1e of the predator, turning it more effective in the controI of the aphid (AU)