Impact of rearing temperature and water pH on longevity and pesticide resistance in Aedes aegypti (Diptera: Culicidae)

Background: Aedes aegypti (Diptera: Culicidae) is considered as one of the main arboviral disease vectors around the planet. Because A. aegypti is an ectotherm and breeds in fresh water pools, climatic conditions influence its biology, distribution, population dynamics and vectorial capacity. To...

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Autor Principal: López Latorre, María de los Ángeles
Formato: bachelorThesis
Idioma: en_US
Publicado: PUCE 2018
Materias:
Acceso en línea: http://repositorio.puce.edu.ec/handle/22000/14165
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Sumario: Background: Aedes aegypti (Diptera: Culicidae) is considered as one of the main arboviral disease vectors around the planet. Because A. aegypti is an ectotherm and breeds in fresh water pools, climatic conditions influence its biology, distribution, population dynamics and vectorial capacity. To investigate the potential impact of future climate change on A. aegypti´s biology, we studied the effect of variations in environmental temperature and the pH of breeding water on this species longevity and pesticide resistance. Methods: Mosquitoes of both geographic (experimental) and control strains were reared under different environmental conditions (environmental temperatures of 25°, 28°, 31°C, maintained throughout the insects´ life span; water pH values of 4, 5 and 6 set at the beginning of larval development). Upon adult emergence, we monitored the longevity and pesticide 25 resistance for each treatment. Results: Both environmental temperature and water pH seem to influence adult longevity and pesticide resistance in A. aegypti. Longevity is significantly diminished in temperatures above or below 28°C, as well as with the acidification of the initial breeding water. Similarly, pesticide resistance seems to decrease significantly in specimens reared above or below 28oC, and in specimens reared in acidic environments. Conclusions: We found that within our temperature gradient there is an optimal rearing temperature (28°C) which maximizes the longevity of our specimens. Additionally, the acidification of the aquatic habitats of larval stages diminished the lifespan of the vector. In reference to deltamethrin resistance, acidification of the breeding water as well as non-optimal rearing temperatures (25 & 31°C) produced lower levels of resistance than those observed in the control treatments, for both temperature and water pH. Although the definitive effects of climate change on A. aegypti biology and physiology in the field are hard to predict, our study contributes novel information about the biology and physiology of this vector species under controlled conditions. This information could help us understand the potential effects of putative future climate scenarios on the transmission of arboviral diseases.