Influência do desmatamento e da sazonalidade na estrutura de comunidades de flebotomíneos em áreas de vegetação mista de floresta, cerrado e mata dos cocais

Abstract

Introduction/Justification. Sandflies are hematophagous insects of the doctor and veterinarian responsible for the transmission of leishmaniasis. The Lutzomyia genus is the most diversified, abundant and of epidemiological importance; its species are distributed in the Americas and throughout Brazilian territory, great development in forest ecosystems. In Maranhão, the original vegetation cover suffered intense degradation over time, damaging fragments of secondary forests, between extensive areas destroyed by agriculture and urbanization. These changes cause changes in the sandfly community. Objective. The objective of the study was to verify if a structure of the sandfly community changes according to the type of environment and seasons. Methodology. A study area included two rural villages: Bom Jesus (municipality of Caxias), where two degraded forest fragments, two peridomiciliary houses and two intradomicile houses were selected; Santana IV (Codó municipality), with two more conserved forest fragments, two peridomiciliary houses and two intra-households. In each environment installed a CDC light trap, from 6 pm to 6 am, once a month, from May / 2012 to April / 2014. The capture effort was 12 traps x 12 hours x 24 months = 3,456 hours. Results. 36 species were found, the most abundant being L. whitmani (50.69%), L. longipalpis (22.33%), L. evandroi (5.45%) and L. walkeri (4.69%), L. lenti (3.38%) and L. termitophila (2.26%). The other 30 species showed low density, that is, less than 2% each. Species richness was greater in the most conserved area (30 species), and the forest contributed with a greater number of species (25), which was also significant in the home (19) peridomicile (20). In the less conserved area, only 17 species were found, distributed in the home (16 species), peridomicile (14) and in the forest (13). Overall, sandflies prevailed in the dry season and in peridomiciliary areas, in both areas, due to the large concentration of domestic animals available in backyards, which function as important blood sources for the females of these leishmaniasis vector insects. Conclusion. The greater conservation of vegetation around the village of Codó, justifies the greater richness of species in this area, when compared to the more degraded state of vegetation cover in the village of Caxias. The reduction of forests by human activities as a whole affects the structure of the sand fly community. The establishment of rural settlements in the vicinity of degraded forest areas has led to the adaptation of species of sandflies in these new environments, which justifies the greater abundance of sandflies in the city of Caxias, with more time of implantation.