Oviposition dynamics of Aedes aegypti in Central Argentina

Abstract

Aedes (Stegomyia) aegypti (L.) (Diptera: Culicidae) is the vector of multiple arboviruses. To evaluate the association between environmental factors and the oviposition activity of Ae. aegypti in Argentina, data on the presence and abundance of eggs were collected using ovitraps, between September of 2018 and May of 2019, in the cities of Villa María, Río Cuarto and Salsipuedes (Córdoba province, Argentina). We analysed the relationships between oviposition and five environmental factors: Temperature, precipitation, vegetation cover, human population density and distance to sites with a potential high density of larval habitats, like cemeteries and trash dumps. Environmental factors' data were collected using satellite image products. The oviposition activity was randomly distributed in three cities. Using generalized linear mixed models, we show that the house where each ovitrap was placed was a source of variability in oviposition, suggesting the relevance of microsite factors and the importance of domestic control actions. Ae. aegypti oviposition was positively correlated with night-time temperature of the previous 3 weeks, and in a context-dependent manner, it was positively correlated with human population density, vegetation cover and precipitation. The consistency and magnitude of these relationships varied between cities, indicating that oviposition is related to a complex system of environmental variables.

Phenotypic Variations of Aedes aegypti Populations and Egg Abundance According to Environmental Parameters in Two Dengue-Endemic Ecoregions in Paraguay

“…In rural areas, soil moisture conservation may stimulate oviposition of females in more protected places with access to food, and it seems to be related to the structure of the surrounding vegetation. 46 Urbanization seems to be an important protagonist in the microevolutionary processes related to environmental modifications, 19 which could lead to a population structuring of Ae. aegypti in the country.…”

Environmental Variables Related to Aedes aegypti Breeding Spots and the Occurrence of Arbovirus Diseases

“…Therefore, regarding the Aedes aegypti oviposition dynamics, meteorological factors were also analyzed in the literature. As investigated by Sánchez-Díaz et al [96], in Argentina, when identifying the night temperature and, in a context-dependent manner, the rainfall, vegetal coverage and demographic density influence the vector's proliferation in a given region. Tuladhar et al [83], upon evaluating the effects of meteorological factors in the seasonal prevalence of vectors in the mountain range and plains regions in Nepal, revealed that the factor temperature-rain and relative humidity contributed to the Aedes vectorial indexes.…”