Distinct feeding strategies of generalist and specialist spiders

GABRIEL POMPOZZI; LUIS FERNANDO GARCÍA; LENKA PETRÁKOVÁ; STANO PEKÁR

ECOLOGICAL ENTOMOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2019 p. 129 - 139

0307-6946

1. Feeding behaviour of generalist and specialist predators is determined by a variety of trophic adaptations. Specialized prey-capture adaptations allow specialist to regularly catch relatively large prey. As a result specialists might be adapted to exploit each prey more thoroughly than generalists. 2. We expected that obligatory specialist cursorial spiders feed less frequently than generalists but for a longer time and thus their foraging pause is longer. First, we compared the feeding frequencies of three generalist spider species (Cybaeodamus taim, Harpactea hombergi, Hersiliola sternbergsi) and three phylogenetically related specialist species: myrmecophagous Zodarion rubidum, and araneophagous Nops aff. variabilis and Palpimanus orientalis. 3. Generalists captured more prey than specialists; exploited each prey for a significantly shorter time than specialists, and their foraging pause was shorter than in specialists. Generalists gained significantly less relative amount of prey mass than specialists. 4. Second, we compared the prey DNA degradation rate in the gut of generalists and specialists by means of PCR. The degradation rate was not significantly different between specialists and generalists: the detectability half-life was estimated to exist 14.3 days after feeding. 5. This study shows that the feeding strategies of cursorial generalist and obligatory specialist spiders are different. Obligatory specialists have evolved a feeding strategy that is based on thorough exploitation of few large preys, whereas generalists have evolved a strategy that is based on short exploitation of multiple small prey items.