RANGE OF PREY ITEMS CAPTURED BY FOUR SPECIES OF WEB-WEAVER SPIDERS (ARACHNIDA: ARANEAE) IN A COCOA AGROECOSYSTEM IN CHIAPAS, MEXICO

Abstract

Spiders can contribute to control of pest insects. Web-weaver spiders are common in many agroecosystems and, being sedentary, they are adequate for this type of studies. This paper deals with prey selection by four species of spiders, two orb-weavers (OW) and two cob-weavers (CW) and differences in diets, among species and among guilds, were analyzed. Field work was done in a cocoa plantation in Chiapas, Mexico, where the potential and actual preys for each spider species were sampled. Composition and proportion of captured prey differ from that of potential prey, showing a biased predation from their environmental availability. Spiders showed differences in diet composition and amplitude. OW had more specializaed diets than the CW, but overlap analyses shown higher similitude among CW, revealing that OW share a lower number of prey in common than the CW. Each of the four spider species over-predated several families of pest insects, but CW over-predated a higher proportion of these.