Functional response, multiple feeding and wasteful killing in a wolf spider (Araneae: Lycosidae)

Feeding behaviour of the wolf spider Pardosa hortensis Thorell (Araneae: Lycosidae) was studied in the laboratory under different prey densities. Feeding characteristics were monitored by a behaviour registering computer program. The amount of prey eaten in the different prey density treatments indicated a Holling type II functional response. Handling time was negatively correlated with prey density. At higher prey densities spiders sometimes attacked and fed on more than one prey item at the same time. Consumption rate during such multiple feeding events was higher than during single feeding. However, multiple feeding was much less frequent than single feeding. Killing without feeding and the partial consumption of the prey was also observed in high prey densities. The degree of this behaviour was positively correlated with prey density. The observed feeding strategy of this wolf spider suggests that spiders can have a positive role in controlling agricultural pests in a density sensitive way.