Predatory versatility and intraspecific interactions of spartaeine jumping spiders (Araneae: Salticidae):Brettus adonis, B. cingulatus, Cyrba algerina, andPhaeaciussp. indet.

Abstract

Abstract The behaviour of four species (Brettus adonis, B. cingulatus, Phaeacius sp. indet. (Sri Lanka), Cyrba algerina (France & Portugal)) of a primitive salticid subfamily, Spartaeinae, was investigated in the laboratory, and observed in the field. B. adonis, B. cingulatus, and C. algerina were found to be versatile predators. As well as being, like typical salticids, effective cursorial predators of insects, they also invaded alien webs, acted as aggressive mimics by performing a variety of vibratory behaviours, captured and fed on the host spider (araneophagy), and fed on insects (klepto-parasitism) and eggs (oophagy) they found in invaded webs. Phaeacius sp. indet. neither invaded webs nor was an active cursorial predator of insects. Instead, it was a highly eucryptic, sedentary ambushing specialist that sat on tree trunks and lunged downward on passing insects. Although they did not spin prey-capture webs, each of the four species moulted in a silken structure which crudely resembled a web. Cyrba sometimes spun rudimentary enclosing nests somewhat resembling typical salticid nest. Intraspecific interactions of B. cingulatus and C. algerina consisted of visual and postcontact (tactile, chemotactic), but not vibratory, displays. These displays were similar to displays of other salticids. In Cyrba, behaviour that brings legs and palps into lengthy contact with the substratum was well developed and was possibly related to the spider’s heavy reliance on pheromonal communication. Results from this study are discussed in relation to a hypothesis of Jackson & Blest (1982), which proposes that ancestral salticids were web-builders, web-invaders, and aggressive mimics.