Cold season mortality and hatching behavior of Aedes aegypti L. (Diptera: Culicidae) eggs in Buenos Aires City, Argentina

SYLVIA FISCHER; IRIS SOLEDAD ALEM; MARÍA SOL DE MAJO; RAÚL ERNESTO CAMPOS; NICOLÁS SCHWEIGMANN

JOURNAL OF VECTOR ECOLOGY

SOC VECTOR ECOLOGY

Lugar: Idaho, EEUU; Año: 2011 vol. 36 p. 94 - 99

1081-1710

The populations of Aedes aegypti survive the cold season in the egg stage in temperate regions. We studied the cold season mortality of Ae. aegypti eggs and their subsequent hatching pattern in Buenos Aires city. Eggs were exposed during the winter season (three months) in three neighborhoods located along a gradient of distance to the coast of the Río de la Plata river, coincident with a gradient of activity of Ae. aegypti. Results showed lower mortalities (30.6%) as compared to those from tropical regions during the dry season. Significant differences in egg mortalities among sites were detected, with a maximum value at the coastal site (46%), and a minimum value at the most continental site (9%). Post experimental hatching response of eggs differed among exposure sites, with highest proportion of hatched eggs at first immersion in the coastal site and lowest proportion in the most continental site. Hatching proportion also differed between age classes, with older (early laid) eggs hatching later than new (late laid) ones. Our results provide the first information of Ae. aegypti egg mortality in temperate South America, and support the hypothesis of different egg mortality associated with abundance patterns of Ae. aegypti in Buenos Aires city.