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

实验分析了寄生蜂幼虫种内和种间竞争的机理。本研究选用的三种昆虫分别为万寿星异翼蝇、基底Dinarmus和拟异翼蝇，均为中国胼手眼的寄生性幼虫。我们首先证实了这三种黄蜂实际上表现出超寄生和多重寄生。我们使用专门设计的观察板观察了种内和种间的幼虫竞争。我们得到了以下结果。同时引进同种卵总是从一个寄主产生一个黄蜂后代。两个同种卵的时滞引入也只产生一个黄蜂后代。哪个个体出现取决于时间滞后。在72或96小时的时差中，第一个到达的人总是获胜。然而，由于48小时的时差，后来者总是赢。同时引入异种卵表明，在种间幼虫竞争中，任何物种都不存在固有的优势。异种卵子的时滞引入表明，先到者总是在竞争中获胜。时差越长，第一个来的人越强。

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.