Abstract ID: 722

The Effects of Climate and land Cover change on mosquito (Anopheles sp) vectors of malaria in northern Amazonia, Brazil

Few studies have so far compared the changes in anopheline populations in newly anthropized areas. In this work the influence of rainfall and of the different levels of anthropic changes of the natural environment on the diversity of malaria vectors was compared in two areas. Adult mosquito collections were performed in 8 localities distributed in two areas of tropical rain forest with different degrees of land use and vegetation cover change. Samples were obtained in February, May, August and November of 2004 in the municipality of Cantá, State of Roraima. Area A was a farm where the natural vegetation has been intensively changed by cattle raising while area B was close to a natural lake, surrounded by forest patches and a few scattered huts. The Shannon-Wiener diversity index was used to compare the species composition of the two areas studied. A total of 2,298 adult mosquito specimens were collected in all localities; area A had 55.5% of the specimens and area B 44.5%. Eleven Anopheles species were found in area A and eight in area B. Anopheles albitarsis s.l. (45.5%) was the most abundant species, followed by An. darlingi (19.2%) and An. triannulatus (19.2%) and An. nuñeztovari (10.4%). In area A, a significantly higher diversity of Anopheles species was observed during the rainy season and February (dry season) presented a significantly lower species richness in relation to the other months. The most important species vectors of malaria – An. darlingi and An. albitarsis – were more abundant in area A. Daily richness and diversity (H’) were significantly higher in the less intensively used area B.

Session:  LCLUC and Human Dimensions - Land-cover and climate change, human population and infections in the Amazon: Current linkages and future risks.

Presentation Type:  Oral