Eclosion rate, development and survivorship of Aedes albopictus (Skuse)(Diptera: Culicidae) under different water...

In tropical areas, where vector insects populations are particularly numerous, temperature usually range between 25 degrees C and 35 degrees C. Considering the importance of such temperature variation in determining mosquitoes population dynamics, in this work the developmental, eclosion and survival rates of the immature stages of Aedes albopictus (Skuse) were compared under constant 25, 30 and 35 degrees C (using acclimatized chambers) and environmental (25 degrees C to 29 degrees C) temperatures. The hatching rate was considered as total number of larvae recovered after 24h. The development period as well as larval and pupal survival rate were evaluated daily. Eclosion rate was significantly higher under environmental temperature than under the studied constant temperatures, suggesting that temperature variation may be an eclosion-stimulating factor. The mean eclosion time increased with the temperature, ranging from 2.8h (25 degrees C) to 5.2h (35 degrees C). The larval period was greatly variable inside each group, although it did not differ significantly amongst groups (11.0 +/- 4.19 days), with individuals showing longer larval stages in water at 35 degrees C (12.0 +/- 4.95 days) and environmental temperature (13.6 +/- 5.98 days). Oppositely, survival was strongly affected by the higher temperature, where only one individual lived through to adult phase. The results suggest that population of Ae. albopictus from Recife may be adapting to increasing of environmental temperatures and that the limiting temperature to larval development is around 35 degrees C.