Arthropod prey of farmland birds: their spatial distribution within a sprayed field with and without buffer zones.

Abstract

The distribution of arthropods was investigated within two cereal fields using a two-dimensional grid of pitfall traps. One field was then sprayed with dimethoate leaving a 6m unsprayed margin around one half of the field. Reinvasion was then monitored over the following month. Data was analysed using Spatial Analysis by Distance Indices (SADIE) incorporating a new clustering index. Arthropods exhibited a heterogeneous distribution within the fields which fluctuated through time, although numbers were usually highest within 60m of the field edge. Arthropods within the 6m buffer zone did not appear to be protected at the time of spraying, however, reinvasion was more extensive within the area of field surrounded by a buffer zone.