Comparative ecology of Gerris remigis (Hemiptera: Gerridae) in two habitats: a paradox of habitat choice

Publisher Website
Google Scholar
Abstract
This study compares the population ecology of Gerris remigis (Hemiptera: Gerridae) in two habitats: a cool mountain stream, representing the characteristic habitat of this species, and the atypical habitat of a small, warm pond. Neither habitat supported breeding populations of any other gerrid species. The populations on the two sites were found to differ significantly with respect to population dynamics, dispersal, phenology, and wing dimorphism. Overall, the population on the pond was more productive than that on the stream, indicating that G. remigis can be highly successful in a warm, lentic habitat, in the absence of competing species. However, in spite of this success, adult G. remigis actively avoided the lentic site. Thus habitat choice in this species cannot be mediated solely by interspecific competition. Comparisons of the two sites suggest that current, temperature, and (or) shelter from direct sunlight and wind may act as proximate cues for habitat choice in this species. The striking differences between the two study populations are also evidence of a very high degree of phenotypic plasticity, which allows G. remigis to respond to differences in habitat characteristics on a very fine scale.