Mosquitoes of the Caatinga. III. Larval Habitats, Frequency, and Dynamics of Immature and Adult Stages in a Dry Brazilian Forest.

Even though the seasonally dry tropical Caatinga forest is an historically neglected biome, recent studies have enhanced our knowledge of its biodiversity. We investigated larval habitats as well as the frequency and dynamics of immature and adult Culicidae in a conservation unit within the Caatinga in the Brazilian state of Sergipe. We carried out monthly surveys between July 2011 and October 2012 to count both immature (tree holes, bromeliad tanks, ponds, and rock holes and depressions) and adult individuals (Shannon traps baited with light). In total 8,021 individuals representing 32 taxa, eight of which are currently undescribed, were collected. The majority of the specimens collected came from tree holes followed by bromeliads, ponds, and rock depressions. Ponds had the highest species richness in this survey while the bromeliad fauna exhibited high endemicity. We also reveal a correlation between precipitation during the month prior to collection and the abundance of immature individuals in tree holes. Peaks in Haemagogus sp. near spegazzinii and Aedes terrens abundance were observed soon after rain, whereas Culex conservator was abundant during the rainy season in tree holes evidencing a species rotation within this habitat. Although the results of this study contribute to our knowledge regarding the distribution of mosquitoes in Brazilian semiarid region, further taxonomic studies will be required to fully understand the richness and endemism of the Neotropical Culicidae fauna.

Sandfly fauna in an area endemic for visceral leishmaniasis in Aracaju, State of Sergipe, Northeast Brazil.

INTRODUCTION: In recent years, visceral leishmaniasis, a major public health problem, has been spreading from the rural to urban areas in many areas of Brazil, including Aracaju, the capital of the State of Sergipe. However, there are no studies of the sandfly fauna in this municipality or its variation over the year. METHODS: Phlebotomine sandflies were collected from a rural area of Aracaju from September 2007 to July 2009. Modified CDC ultra-violet (UV) light traps were used to evaluate sandfly monthly distribution and their presence in the domestic and peridomestic environments. RESULTS: The most abundant species was Lutzomyia longipalpis (90.4%) followed by Evandromyia lenti (9.6%). A chicken shed trap site had the highest proportion of L. longipalpis (51.1%) and large numbers of L. longipalpis were also collected in the houses closest to the chicken shed. There was a positive correlation between monthly rainfall and L. longipalpis abundance. CONCLUSIONS: Lutzomyia longipalpis is the most abundant species and is probably the main vector of the visceral leishmaniasis agent in the rural area of Aracaju. An increase in L. longipalpis frequency was observed during the rainy season. The peridomicile-intradomicile observations corroborate the importance of chicken sheds for the presence of L. longipalpis in the peridomestic environment. The great numbers of L. longipalpis inside the houses confirm the endophilic behaviour of this species and the possibility of visceral transmission in the intradomicile.

Sandfly fauna in an area endemic for visceral leishmaniasis in Aracaju, State of Sergipe, Northeast Brazil / Fauna flebotomínica em área endêmica de leishmaniose visceral em Aracaju, Estado de Sergipe, Nordeste do Bras

INTRODUCTION: In recent years, visceral leishmaniasis, a major public health problem, has been spreading from the rural to urban areas in many areas of Brazil, including Aracaju, the capital of the State of Sergipe. However, there are no studies of the sandfly fauna in this municipality or its variation over the year. METHODS: Phlebotomine sandflies were collected from a rural area of Aracaju from September 2007 to July 2009. Modified CDC ultra-violet (UV) light traps were used to evaluate sandfly monthly distribution and their presence in the domestic and peridomestic environments. RESULTS: The most abundant species was Lutzomyia longipalpis (90.4%) followed by Evandromyia lenti (9.6%). A chicken shed trap site had the highest proportion of L. longipalpis (51.1%) and large numbers of L. longipalpis were also collected in the houses closest to the chicken shed. There was a positive correlation between monthly rainfall and L. longipalpis abundance. CONCLUSIONS: Lutzomyia longipalpis is the most abundant species and is probably the main vector of the visceral leishmaniasis agent in the rural area of Aracaju. An increase in L. longipalpis frequency was observed during the rainy season. The peridomicile-intradomicile observations corroborate the importance of chicken sheds for the presence of L. longipalpis in the peridomestic environment. The great numbers of L. longipalpis inside the houses confirm the endophilic behaviour of this species and the possibility of visceral transmission in the intradomicile.

INTRODUÇÃO: Nos últimos anos, a leishmaniose visceral, um importante problema de saúde pública, vem apresentando expansão das áreas rurais para as urbanas de muitas regiões do Brasil, incluindo-se Aracaju, capital do Estado de Sergipe. No entanto, não existem estudos sobre a fauna de flebotomíneos presente nesse município ou de sua distribuição ao longo do ano. MÉTODOS: As coletas de flebotomíneos foram realizadas em uma área rural de Aracaju, capital do Estado de Sergipe no periodo de setembro de 2007 a julho de 2009. Armadilhas CDC modificadas acopladas com luz ultravioleta (UV) foram utilizadas para avaliar a distribuição mensal e a presença de flebotomíneos nos ambientes doméstico e peridoméstico. RESULTADOS: Lutzomyia longipalpis foi a espécie mais abundante (90,4%), seguida por Evandromyia lenti (9,6%). Os locais com as maiores quantidades de L. longipalpis (51,1%) foram um galinheiro e as casas mais próximas a ele. Houve uma correlação positiva entre a precipitação mensal e a abundância de L. longipalpis. CONCLUSÕES: Lutzomyia longipalpis é a espécie mais abundante e, provavelmente, o principal vetor do agente da leishmaniose visceral na área rural de Aracaju. Foi observado um aumento na frequência de L. longipalpis nos meses chuvosos. As coletas realizadas no ambiente externo e interno dos domicílios reforçam a relevância dos galinheiros para a presença de L. longipalpis no ambiente peridoméstico. O grande número de L. longipalpis dentro das casas confirma o comportamento endofílico dessa espécie e a possibilidade de transmissão intradomiciliar da leishmaniose visceral.