Consequences of pesticide use on spider communities in mango orchards.
Rayner D., Coates M., Newby R.
Author Affiliation: Department of Biology, Central Queensland University, Rockhampton, Queensland 4702, Australia.
Revue Suisse de Zoologie Hors serie : 537-542
Abstract : A preliminary study was performed during spring/summer 1993 to determine the effects of pesticide use on spider communities in central Queensland mango orchards. Twelve orchards were used and divided into 3 types according to the amount of pesticide used: unsprayed orchards with no pesticides; infrequently sprayed orchards with heavy applications of fungicides (copper oxychloride and mancozeb) but minimal insecticides (methidathion, endosulfan and dimethoate); and frequently sprayed orchards with heavy applications of both fungicides and insecticides. The results suggested that the frequent use of pesticides reduced abundance, species richness and species diversity of spiders, while infrequent application of pesticides did not appear to result in a change in these factors. However, when relative species abundances in orchards which have had frequent, infrequent and no pesticide applications over 3 sampling periods, were compared by non-parametric multivariate analysis, changes in community structure were indicated. Web-building and hunting spiders were both found to be vulnerable to pesticides.