Environmental determination of dragonfly assemblage in aquaculture ponds

摘要

Odonate larvae are important components of aquatic environments in tropical areas. They also develop in aquaculture ponds, where they can cause economic losses. In this study, we have tried to describe the general community patterns in aquaculture ponds in Vicosa, south-eastern Brazil. Our aim is to evaluate how environmental and bionomic factors can determine their composition and species richness. We identified two groups of species (plants and bottom-dwellers) based on larval microhabitat preferences, Vegetation determines the occurrence of some species whose adults select certain plants for oviposition. The ponds with more extreme conditions (extensive cover of plants or vegetation absent) showed lower species richness than those with intermediate conditions, Coryphaeshna adnexa and Brachmesia furcata were of larger size but had low abundance or were only collected accidentally. Species of intermediate size (Tramea cophysa, Micrathyria spp., Orthemis discolor and Erytrodiplax fusca) were more abundant and are considered as potential predators of fish fry. [References: 50]