Seasonal Abundance of Lutzomyia longipalpis (Dipteral Psychodidae) at an Endemic Focus of Visceral Leishmaniasis in Colombia

Abstract

Ecological studies on the sand fly Lutzomyia longipalpis (Lutz & Neiva) were conducted during 1990-1993 in a small rural community in Colombia where American visceral leishmaniasis is endemic. Standardized weekly sand fly collections made from pigpens and natural resting sites displayed a bimodal annual abundance cycle, with a small peak occurring in October-November and a larger one in April-May. Time series analysis was employed to quantify the associations between sand fly abundance and weather factors (temperature, relative humidity, and rainfall). In addition to a prominent 6-mo cycle. Fourier analysis of the collection data demonstrated that the L. longipalpis population also exhibited a 5- to 8-wk cycle that may represent the length of larval development. Autoregressive moving average models were fit to weekly collection data and their residuals were regressed against rainfall, temperature, and relative humidity. A significant positive association between female L. longipalpis abundance and the relative humidity and rainfall recorded 3 wk earlier was found, indicating that these factors may be of value in predicting sand fly abundance. Additionally, these data indicated that L. longipalpis larvae may become quiescent during adverse conditions.

Study of sand fly fauna in an endemic area of American cutaneous leishmaniasis and canine visceral leishmaniasis in the municipality of Espírito Santo do Pinhal, São Paulo, Brazil

“…The combined effects of rainfall, air temperature, evapotranspiration and soil water balance likely influence the quality of the breeding habitats, consequently determining the fluctuations in the adult sand fly population (Rutledge & Ellenwood 1975, Morrison et al 1995, Ferro et al 1997, Casanova et al 2009). Periods of moderate water surplus seem to be favourable for a population increase of the four most abundant species in Espírito Santo do Pinhal.…”

Survival, Population Size, and Gonotrophic Cycle Duration ofNyssomyia neivai(Diptera: Psychodidae) at an Endemic Area of American Cutaneous Leishmaniasis in Southeastern Brazil

“…In the same Conchal study area, Casanova (2001) identiÞed leaf litter of the residual gallery forest and the base of trees situated in the peridomicile as the main larval habitats for N. neivai. Probably the combined effects of rainfall, air temperature, evapotranspiration, and soil water balance inßuence the quality of these breeding habitats, consequently determining the adult sand ßy population ßuctuations (Rutledge and Ellenwood 1975, Morrison et al 1995, Ferro et al 1997.…”

Distribution and Abundance of Phlebotominae, Vectors of Leishmaniasis, in Argentina: Spatial and Temporal Analysis at Different Scales

“…Time series statistics were computed by the SYSTAT software package [29]. Autoregressive integrated moving average (ARIMA) models and multivariate general linear stepwise models ( P = 0.15 including covariance) were tested [29, 30]. …”