Stoidis Aurata (Araneae: Salticidae), A Spider Predator of Ants

Abstract

Stoidis aurata (Hentz), a salticid spider occurring in a variety of leaf litter habitats, was observed in the field attacking ant workers. In the laboratory it fed on 21 of 23 ant species offered, representing 17 genera in 5 subfamilies. S. aurata had difficulty in overcoming workers of genera Aphaenogaster, Crematogaster, Tetramorium, and Formica, and did not consistently attack the larger individuals of Pogonomyrmex badius (Latreille), Camponotus abdominalis floridanus (Buckley), or the workers of Odontomachus ruginodis (Wheeler). The hard exoskeletons of Cyphomyrmex rimosus minutus Mayr and Trachymyrmex septentrionalis (McCook) apparently protected the workers of these 2 species from capture by S. aurata. The spider attacked from directly in front of the ant 91% of the time; 77% of these captures were made by grasping the ant by the dorsum of the alitrunk. No other salticid was observed, either in the field or the laboratory, to feed on ant workers, even though individuals of 20 other salticids were tested under similar conditions. Two species of jumping spider, Plexippus paykulli (Audouin) and Thiodina sylvana (Hentz), were observed feeding on alate ants.