Cold season mortality under natural conditions and subsequent hatching response of Aedes (Stegomyia) aegypti (Diptera: Culicidae) eggs in a subtropical city of Argentina

JAVIER ORLANDO GIMÉNEZ; SYLVIA FISCHER; LAURA ZALAZAR; MARINA STEIN

JOURNAL OF MEDICAL ENTOMOLOGY

ENTOMOLOGICAL SOC AMER

Lugar: Lanham; Año: 2015 p. 1 - 7

0022-2585

Intemperate and subtropical regions, populations of Aedes (Stegomyia) aegypti(L.) survive unfavorable winter conditions in the egg stage. Knowing theirsurvival rates can be of great interest for the health authorities in charge ofcontrol activities. In this study, we analyzed the mortality of Ae. aegyptieggs exposed to the cold season as well as their hatching patterns underlaboratory conditions in the city of Resistencia, Chaco, Argentina. Themortality rate was 48.6%. No statistically significant differences wereobserved in the mortality of eggs exposed at different sites. Hatching responsediffered significantly among the successive postexposure immersions, with thehighest proportion of hatched eggs during the first immersion. These resultsshow that the mortality rate of Ae. aegypti eggs exposed to the cold season ina subtropical city of Argentina was higher than those from temperate climateregion. The additional mortality of eggs in our study might be related tofungal development (an unexpected event), which was not observed in research intemperate climate. The hatching pattern observed in this study ensures a rapidincrease of the population at the beginning of the favorable breeding season,but it also maintains a batch with delayed hatching eggs, posing a risk for thecommunity.