Odonata as indicators of habitat quality at lakes in Louisiana, United States

Larval Zygoptera and Anisoptera were sampled at 3 lakes. Environmental variables such as chemical composition, water current, turbidity, and vegetation cover were measured. Cross Lake had the most spp. and greater diversity of spp. than Chaplin’s and Sibley lakes. Most Zygoptera spp. were found at Cross Lake where carbon availability was highest. Classification and ordination analysis produced similar species groups, providing strong evidence for species assemblages being determined by the measured environmental variables. Tolerant spp. included Enallagma civile, Erythemis simplicicollis and Plathemis lydia. Spp. only present at Cross Lake (incl. Argia sedula, Enallagma basidens, Ischnura hastata, I. kellicotti, Celithemis eponina, Libellula luctuosa. Erpetogomphus designatus, L. pulchella, Nasiaeschna pentacantha) were associated with lower levels of ammonia, conductivity, pH, and higher levels of oxygen and increased vegetation. Cross Lake provided habitat that could support more spp. and was important for spp. that were less tolerant of ammonia and anoxia. This study provides baseline data for future monitoring and conservation management of these lakes.