Spiders as Biological Control Agents
Spiders exert a powerful negative pressure on insect populations. While this activity has been difficult to document, recent studies have consistently shown that spiders are important components of agricultural systems (Young & Edwards 1990, Nyffeler & Benz 1987, Riechert & Lockley 1984, Riechert & Bishop 1990, Mansour et al.1983). For a summary of the research to date see Wise (1993). Some spiders are able to identify insect eggs as food items (Richman et al. 1980) and thus may serve as important predators on this stage. It seems likely that, from an economic standpoint, spiders do more good than harm, even when venomous spiders are taken into account.