THE PREY OF THE SPIDER LINYPHIA TRIANGULARIS (CLERCK) (ARANEAE, LINYPHIIDAE)

Abstract

In a study of the natural foods of the spider, Linyphia triangularis (Clerck), a weekly 3-hour watch of 50 webs was kept from May 1 to October 15. A total of 581 insects representing 153 species entered webs during the observation periods. Most of these were represented by very few individuals, and more than half of the spiders' diet was supplied by about 20 species of prey. Most of the prey were winged adults. Most of the species were present in the community in the adult stage for a short time only. Thus over the season the spider exploited a constantly changing complex of prey species. At any one time the spider relies on a very few species for most of its food. Of all the insects in the community, only those with certain characteristics of distribution, morphology, and behavior are available to the spiders. Suitable characteristics occur in a wide range of distantly related species; thus the spider is not restricted in its prey to any taxonomic group. From the insects that enter the webs the spider exercises some selection. There is a strong suggestion that new or strange species entering a web tend to be rejected on their first few entries, but if they continue to enter they will eventually be accepted.