The hypothesis that a component of genetic variation for polygenic fitness traits is maintained by environmental heterogeneity was tested using an experimental system involving two species of flour beetles, Tribolium castaneum and T. confusum. Replicated populations of each species from a number of environmental treatments were analyzed for various fitness components following almost 60 generat...

Hypothesis: Dispersal outside a local population maintains population density below the possible maximum, but within a single local population selection acts against dispersal and consequently against such maintenance. Individuals that disperse exhibit lower fitness that is correlated with their smaller body size. Organism: Laboratory populations of Tribolium confusum beetles. Methods: Four con...

Interactions between stored product pest insects and their parasitoids are well known to be mediated by infochemicals. However, little knowledge is available about the extent which parasitoid responses host kairomones improve search parasitization success. Here, we tested whether release of host-specific confused flour beetle, Tribolium confusum , improves finding larval ectoparasitoid Holepyri...