The use of barrier-connected pitfall trapping for sampling predatory beetles and spiders

The efficiency of barrier-connected pitfall trapping was compared to conven tional single traps or arrays. For ground-active beetles, the use of a pitf all system incorporating a wetting agent with five traps arranged in a cros s formation connected by plastic barriers was more efficient than a single dry trap by at least an order of magnitude and at least twice as efficient as five traps without connecting barriers. It is argued that the efficiency of pitfall trapping may be improved markedly by using barrier-connected tr aps, particularly for some carabid and staphylinid beetles and lycosid spid ers. Capture of linyphiids was not improved by the use of barriers and was dependent only on the use of wetting agent and number of traps used.