Maternal body size affects sex allocation in a gregarious parasitoid.

In parasitoid wasps, body size is a key predictor of reproductive success, as size is often correlated with increased gamete production. In Hymenoptera, due to haplodiploid sex determination, sperm are required to produce daughters but not sons, so sex allocation relies on a female's ability to obtain and manage a finite supply of sperm. Body size may, therefore, affect sex allocation if smaller males provide fewer sperm, or if larger, more fertile females deplete their sperm supplies by fertilizing more eggs.

Sperm Limitation Produces Male Biased Offspring Sex Ratios in the Wasp, Nasonia vitripennis (Hymenoptera: Pteromalidae).

Haplo-diploid sex determination in the parasitoid wasp, Nasonia vitripennis (Walker), allows females to adjust their brood sex ratios. Females influence whether ova are fertilized, producing diploid females, or remain unfertilized, producing haploid males. Females appear to adjust their brood sex ratios to minimize 'local mate competition,' i.

Priority determines Tribolium competitive outcome in a food-limited environment.

Flour beetles are a classic model system for studying competitive dynamics between species occupying the same ecological niche. Competitive performance is often interpreted in terms of biological species traits such as fecundity, resource use, and predation. However, many studies only measure competitive ability when species enter an environment simultaneously, and thus do not consider how the relative timing of species' arrival may determine competitive outcome (i.