Predatory behavior of tetragnatha praedonia (araneae: Tetragnathidae)

Abstract

Synopsis YOSHIDA,M,(Department of Biology and Geology, Faculty of Science and Engineering, Ritsumeikan University, Kyoto 603, Japan): Predatory behavior of Tetragnatha praedonia (Araneae: Tetragnathidae). Acta arachnol., 35: 57-75 (1987). The predatory behavior of Tetragnatha praedonia was studied. The prey consisted of mainly Diptera, especially midge flies, smaller than 3 mm in body length. When capturing small prey, this species applied mainly “Seize-Pull out” strategy to them; that is, it plucked the web to locate the prey, ran and seized it in the jaws, pulled it out of the web, then carried to the hub and fed there. When given large prey more than 5 mm, this species captured them by various strategies. It captured Lepidoptera mainly by “Bite-Wrap” strategy; that is, the prey was immobilized by bite, then was wrapped with silk. On the other hand, craneflies and damselflies were captured by three strategies, that is, “Seize-Pull out”, “Bite-Wrap” and “Wrap-Bite”. In “Wrap-Bite” strategy, the prey were attacked by wrapping, then bitten by the spider. But, the wrapping seemed to be of little use to immobilize the prey, because this species used the silk with less adhesiveness and did not used the swathes of silk. It was verified that this species can use all the strategies which are used by the advanced araneids such as Argiope argentata. But, it captures mainly small prey by “Seize-Pull out” strategy, and does not use the swathes of silk for attack wrapping. So, the predatory behavior of this species should be situated in the new stage between the primitive stages and the advanced stages in the evolution of araneids' predatory behavior. © 1987, Arachnological Society of Japan. All rights reserved.