Impact of pre-copulatory sexual cannibalism on genetic diversity and efficacy of selection.

Factors that increase reproductive variance among individuals act to reduce effective population size (Ne), which accelerates the loss of genetic diversity and decreases the efficacy of purifying selection. These factors include sexual cannibalism, offspring investment and mating system. Pre-copulatory sexual cannibalism, where the female consumes the male prior to mating, exacerbates this effect.

Stressful environments favor deceptive alternative mating tactics to become dominant.

Background: Deceptive alternative mating tactics are commonly maintained at low frequencies within populations because males using them are less competitive and acquire lower fitness than those using dominant tactics. However, the successful invasion of a male deceptive tactic is plausible if deception carries no fitness cost to females. Among populations of the gift-giving spider Paratrechalea ornata, males very often offer females a deceptive worthless gift, rather than a nutritive gift.

A new species of Edrabius Fauvel (Coleoptera, Staphylinidae, Staphylininae) from Uruguay.

A new rove beetle species, Edrabius uruguayensis Martínez-Villar, González-Vainer Tomasco, sp. nov., associated with the subterranean rodent Ctenomys rionegrensis in Uruguay, is described and illustrated.