PREY HUNTING AND INTERACTIONS AMONG SOCIAL WASP (HYMENOPTERA: VESPIDAE) FORAGERS AND RESPONSES OF CATERPILLARS TO HUNTING WASPS

• Main Author: RAVERET RICHTER, MONICA ANN
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-1988
• Subjects: Biology; Entomology
• ISBN: 9798206785715

The behavior of social wasps as they hunt and the responses of caterpillar prey to hunting wasps are the subjects of this study. I observed and compared the hunting behavior of Polybia occidentalis and Polybia diguetana foragers in Guanacaste, Costa Rica. The wasps differed in how they budgeted their time when foraging and in their responses to prey related cues. The presence of another forager influenced the choice of and access to food by hunting wasps. Both species of Polybia preferentially hovered near occupied rather than unoccupied prey, but their subsequent responses differed. Polybia occidentalis foragers tended to land with other Polybia foragers and to gain access to the occupied prey. Polybia diguetana foragers did not land preferentially with other Polybia. In within and between species tests of wasp pairs, I found that tolerance among wasps varied with prey availability. As the amount of prey increased, the percentage of behavior consisting of high level aggression decreased. Polybia occidentalis foragers did not treat their nestmates preferentially. In between-species tests, both prey availability and the arrival order of wasps affected the tolerance of wasps. There was less aggression overall in the tests where the slightly larger wasp, P. occidentalis, arrived first. Hunting Polybia foragers behaved as if using the following rules: (1) If a forager was able to run off with prey and avoid conflict, she picked up the prey and fled; (2) She fought if she had a chance of excluding others and monopolizing the prey; (3) If the prey was large, both foragers split it. Vespula maculifrons and Polistes fuscatus, two north temperate social wasps, produce sounds of different frequencies when they fly. In the laboratory, Spodoptera eridania (Lepidoptera: Noctuidae) larvae responded differently to sounds of various frequencies in the range of those produced by flying wasps. In the field, these caterpillars responded differently to the approaches of V. maculifrons and P. fuscatus wasps. The caterpillars may perceive frequency differences in the flight sounds of approaching wasps and change their behavior as a result of these signals.