Effect of different agricultural practices on spiders and their prey populations in small wheat fields

Abstract

The influence of different agricultural practices (viz., edge crop, zero tillage sowing and low input of fertilizers) on the density and diversity of spider populations of small wheat fields present in close vicinity were compared in experiments conducted from 2007–2009. The study was conducted in district Sheikhupura, Punjab province, Pakistan. Five fields with different management activities were sampled for spiders using pitfall traps and a visual search method. A total of 23,097 specimens of spiders belonging to 47 species, 21 genera and 12 families were recorded during the study. There was a difference in the density and richness of spiders and high density was recorded in the zero-tillage sown fields and lowest in low-input fields. However, the diversity and evenness did not differ with the habitat types. The analysis of agrobiont species distribution showed that hunting spiders were abundant in zero-tillage sown wheat and orb webs in wheat fields edged with Brassica napus crop. Density of spiders in fields was associated with aphid and collembolan density. Based on this study we can suggest that diversification of management activities can be helpful to maintain spider diversity in the crop which can be helpful in pest management activities.