Effect of Abiotic Factors on Seasonal Population Dynamics ofLutzomyia longipalpis(Diptera: Psychodidae) in Northeastern Brazil

Abstract

The resurgence of visceral leishmaniasis in Brazil increases the need for studies to elucidate the spatial and temporal dynamics of Lutzomyia longipalpis (Lutz and Neiva) (Diptera: Psychodidae), the vector of Leishmania infantum, the causative agent of visceral leishmaniasis in Brazil. Sand flies were captured in peridomestic habitats biweekly for 3 yr. Cross-correlation tests and spectral analysis were used to analyze the simultaneous and lag-time correlations between Lu. longipalpis population densities and abiotic factors of temperature, relative humidity, wind velocity, and rainfall. Distinct seasonal patterns were observed for males and females, with intervals of 6 mo between population peaks for males and 12 mo for females. Peak female population densities lagged 3 mo behind the maximum annual temperature. Female population density was negatively correlated with relative humidity. An increase in average wind velocity was followed by a decrease in the number of females for 2 wk. Understanding the relationship between the seasonal population dynamics of Lu. longipalpis and abiotic factors will contribute to the design of better control measures to decrease transmission of L. infantum and consequently the incidence of leishmaniasis.

Space-time cluster analysis of American visceral leishmaniasis in Bauru, São Paulo State, Brazil

“…Our findings corroborate these results, showing that vector count is related to human and canine AVL incidence 19,21 .…”

Sandflies (Psychodidae: Phlebotominae) survey in an urban transmission area of visceral leishmaniasis, Northeastern Brazil

“…High temperatures alone or associated with other variables had a negative effect on sand flies, probably due to the long rainy season. This inverse correlation between sand flies and high temperature was also reported in the municipality of Nísia Floresta in Rio Grande do Norte (XIMENES et al, 2006), Campo Grande in Mato Grosso do Sul (OLIVEIRA et al, 2008) and Sobral in the state of Ceará (MACEDO et al, 2008). However, in Nísia Floresta, sand flies live at temperatures between 32-36 °C and no significant correlation was found between population density and temperature (XIMENES et al, 2000).…”

Emergência de flebotomíneos (Diptera: Psychodidae) em chão de floresta de terra firme na Amazônia Central do Brasil: uso de um modelo modificado de armadilha de emergência

“…A emergência de flebotomíneos em florestas tropicais parece está relacionada com a precipitação pluviométrica, sendo maior no período de maior precipitação (Arias & Freitas, 1982;Ximenes et al, 2006). Curiosamente, no presente estudo, setembro, mês de baixa precipitação, foi o mês com maior número de flebotomíneos capturados.…”