Influence of different crops and climate factors on the occurrence of green lacewings in agroecological system

Abstract

The green lacewings (Chrysopidae) have been reported in natural ecosystems as well in agroecosystems, intercropping or monocropping. However, the knowledge on their behavior on different agroecosystems is scarce. The present work aimed to determine the diversity of green lacewing species and to evaluate the influence of different agricultural crops, as well as climate factors, on the abundance of these insects in an agroecologically-based organic production system. The study was conducted from September 2008 to August 2009, by performing weekly sampling of Chrysopidae adults in areas of the Integrated Production Agroecological System (SIPA) in Seropédica (RJ), each with one type of cropping system (corn-mucuna rotation/vegetable crops; shaded coffees and sugar cane/brachiaria pasture rotation). A total of 424 adult specimens were collected, belonging to three species: Chrysoperla externa (98.1%), Ceraeochrysa cubana (1.7%) and Ceraeochrysa paraguaria (0.2%). There were no differences on the number of green lacewing adults collected in the crops, although the correlation analysis showed that the crop rotations with grasses favor their abundance. The abundance of green lacewings was also influenced by the climate conditions only in the system of shaded coffees, being negatively correlated with mean air temperature and accumulated rainfall.