Mechanisms of intra- and interspecific competition among wasps parasitic on bean weevil larvae.

点击翻译按钮获取中文摘要

The mechamisms of intra- and interspecific competition between larvae of parasitic wasps were analyzed experimentally. We used three species, Anisopteromalus calandrae, Dinarmus basalis, and Heterospilus prosopidis, all of which are larval perasitoids on Callosobruchus chinensis.We first confirmet that these three wasp species actually showed superand multiparasitisms. We observed the intra- and interspecific larval competitions using the observation plate specifically designed for this research. We obtained the following results.1. Simultaneous introductions of conspecific eggs produced invariably one wasp offspring from one host.2. Time-lag introductions of two conspecific eggs also produced only one wasp offspring. Which individual emerged depended on the time-lag. With 72 or 96 hrs time-lag, the first comer always won. However,with 48 hrs time-lag, the late comer always won.3. Simultaneous introductions of heterospecific eggs showed that there was no inherent superiority in any species for interspecific larval competition.4. Time-lag introductions of heterospecific eggs showed that the first comer always won the competition. The longer the time-lag, the stronger the first comer was.