Insetos associados aos cultivos de Brassica oleracea var. italica, B. oleracea var. botrytis Plenk (Brassicaceae) e Lycopersicon esculentum var. cerasiforme (Solanacea) em sistema orgânico no município de Arapiraca, Alagoas

Abstract

This study aimed to determine the biodiversity of insects in crops of broccoli, tomatoes and cauliflower in an organic system in the city of Arapiraca, Alagoas. Due to increase in vegetable production in the State it is important to identify the species of insects associated with crops studied. Samples were taken weekly and manually, in the period from October to December 2009. The species were determined until the most advanced taxonomic level as possible. Collected insects were identified and the frequency in each they occur was calculated according According to the findings made in to a pre – determined scale. In 9 samples we obtained 463 specimens of insects in the three organic crops, identified in 5 orders and 21 families. Faunal indices (abundance, constancy, dominance, equitabilidade and frequency) were calculated and the feeding habits described. The individuals of the order Hemiptera were the most frequent in all cultivations and the most representative family of the order was Aphididae. Abundance of each family separately, was not significant. It is concluded that the abundance of species collected in the culture of broccolis is confirmed as a good indicator of importance of organic farming.