Richness and abundance of sand fly species in human settlements and degraded forest fragments in Maranhense Amazon

Abstract

The present study analyzes the variation in the richness and abundance of sandflies in rural settlements, with different degrees of forest degradation, in the Amazon of the State of Maranhão. The sandflies were captured in the municipalities of Santa Luzia (moderately degraded area), Senador La Rocque (very degraded) and Governador Nunes Freire (completely degraded), during three consecutive nights, once a month, from May/2012 to April/2014. Overall, 6,810 specimens of 35 species of sandflies, distributed in 13 genera, were captured. The most diverse was Evandromyia (9 species), followed by Psathyromyia (5), Pressatia (3), and Psychodopygus (3). The most abundant species were Nyssomyia whitmani (32.33%), Evandromyia evandroi (14.89%), Lutzomyia longipalpis (12.45%), Brumptomyia avellari (6,73%), Pintomyia damascenoi (6,59%), and Migonemyia migonei (6,46%). In all areas, species richness was greater in forest fragments than in rural peridomiciles, except in that one, whose forest fragment was very degraded. The abundance of individuals was greater in all peridomiciles. The increasing degradation of natural vegetation cover has been reducing forests and the richness of sand fly species. However, the remaining fragments of secondary forests still maintain a considerable number of species, which to a greater or lesser extent frequent adjacent rural settlements. These new environments offer sandflies opportunities (shelters and food sources) necessary for reproduction and proliferation. As a consequence, leishmaniasis begins to change its epidemiological profile, affecting susceptible human populations.