The aim purpose was to study the composition of Chironomidae fauna and the anothers aquatic insects in a temporary dam. Qualitative samples were realized in two periods: August/1995, higher level of water and March/1999, after the completely drying dam for 3 years. Only one species of Chironomidae was registered, Chironomus gr. decorus, in both periods, which contributed with 28.09% for the total aquatic insects fauna in August/95 and it was the only species to colonize the sediment of dam after 3 years of drying period. In August/95 observed the occurrence of Odonata, Coleoptera, Hemiptera, Ephemeroptera and Trichoptera. In this period was evidenced lower values of dissolvid nitrogen (ammonium, nitrite and nitrate), sulfate and electric conductivity compared with March/99. Thus, the aquatic insects fauna were strongly ifluenced by physical and chemycal conditions. Two considerations its may be registred, in spite of appearing of Chironomus gr. decorus, immediately after the dry period: 1. The oviposition by flying females, originating from permanent waters, is the most important means of recolonizing habitat refilled; 2. Or the species it may be survive the desiccation, as larvae in dry sediment or in cocoon during the dry period.
Chironomidae; Chironomus gr. decorus; semi-arid; temporay dam
