Bioactivity of aqueous extracts of annonaceous from the amazon savannah of Roraima on the cowpea aphid

Abstract

Aphis craccivora Koch (Hemiptera: Aphididae), known as the cowpea aphid, is a polyphagous pest that causes severe damage throughout the phenological cycle of several economically important crops. For the control of this hemiptera, as for most agricultural pests, the chemical method has been the most used. Considering the Integrated Pest Management - IPM, the use of plant extracts is an option that has been widely considered. Thus, this study aimed to evaluate the bioactivity of aqueous extracts of Annona glabra, A. hypoglauca, A. montana and A. squamosa leaves, obtained in the Amazonian Savanna of Roraima, Brazil, on A. craccivora under laboratory conditions. Regarding the biological aspects on the cowpea aphid, the toxicity and repellency were evaluated with and without chance of choice. It was verified that the aqueous extracts of the four species of the genus Annona cause mortality in both nymphal and adult stages of A. craccivora, besides presenting repellent effect for this aphid. Because the aqueous extracts of leaves of the studied species present promising effects against A. craccivora, additional field studies of bioactivity of these Annona species on the black aphid, as well as their activity on beneficial and non-target organisms are suggested.