Abstract Most social insects are free living and produce castes that develop in response to extrinsic environmental cues. Caste-forming polyembryonic insects, in contrast, are all endoparasitoids that form social groups inside the bodies of host insects. The best studied polyembryonic wasp is Copidosoma floridanum (Ashmead), which produces ∼3,000 clonal offspring that develop into two castes named reproductive and soldier larvae. Caste determination in this species is mediated by whether or not embryos inherit primary germ cells (PGCs). Prior results showed that C. floridanum increases the proportion of female soldier larvae it produces per host in response to other parasitoids like Microplitis demolitor. Here we show that caste ratio shifts occur through increased formation of embryos lacking PGCs. Our results further indicated that increased soldier production was a specific response to multiparasitism elicited by the chorion of M. demolitor eggs.

中文翻译：

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Copidosoma floridanum（膜翅目：Encyrtidae）在竞争中迅速改变士兵胚胎的产生

摘要 大多数社会昆虫是自由生活的，并产生响应外在环境线索的种姓。相比之下，种姓形成的多胚昆虫都是在宿主昆虫体内形成社会群体的内寄生物。研究得最好的多胚黄蜂是 Copidosoma floridanum (Ashmead)，它产生约 3,000 个克隆后代，这些后代发育成两个种姓，称为生殖幼虫和士兵幼虫。该物种的种姓决定是由胚胎是否继承初级生殖细胞 (PGC) 来介导的。先前的结果表明，C. floridanum 增加了它在每个宿主中产生的雌性士兵幼虫的比例，以响应其他寄生虫（如 Microplitis demolitor）。在这里，我们表明种姓比率的变化是通过缺乏 PGC 的胚胎形成的增加而发生的。