Feeding Patterns of Mosquitoes (Diptera: Culicidae) in the Atlantic Forest, Rio de Janeiro, Brazil.

The stomach contents of culicids from the Atlantic Forest in Rio de Janeiro state, Brazil, were analyzed using the precipitin technique to evaluate the feeding patterns of the species. Sampling was performed from February 2012 to December 2013, using CO2-baited Centers for Disease Control and Prevention traps to catch mosquitoes from 15 00 to 07 00 hours. The following antisera were used: bird, rodent, opossum, human, horse, capybara, lizard, and frog. Of the 325 adult bloodfed females caught and analyzed, 273 (84.0%) reacted in the precipitin test. The percentage of specimens with a positive reaction to a single antiserum included bird (39.2%), rodent (22.5%), opossum (13.2%), capybara (6.6%), horse (5.7%), frog (6.2%), human (4.0%), and lizard (2.6%). The specimens that reacted positively against more than one blood source (46) most frequently presented the following combinations: bird + rodent and bird + frog (17.4%), followed by bird + human (13.0%). The predominance of positive results for birds suggested that the avian-rich environment might have influenced the feeding behavior of the culicids.

A comparative study of the effect of multiple immersions on Aedini (Diptera: Culicidae) mosquito eggs with emphasis on sylvan vectors of yellow fever virus.

The effect of multiple immersions on Haemagogus janthinomys , Haemagogus leucocelaenus , Aedes albopictus and Ochlerotatus terrens eggs was studied. Eggs were collected in April, June, October and December of 2011 in Minas Gerais, Brazil. Most of the Aedes and Ochlerotatus eggs hatched upon the first immersion, while Haemagogus eggs showed a varied instalment hatching response. The number of immersions required for hatching increased for eggs collected closer to the dry winter season.

Morphological differentiation between seven Brazilian populations of Haemagogus capricornii and Hg. janthinomys (Diptera: Culicidae) using geometric morphometry of the wings.

INTRODUCTION: Haemagogus capricornii and Hg. janthinomys females are considered morphologically indistinguishable. We analyzed morphometric variability between Brazilian populations of these species using wing geometric morphometry. METHODS: Size and shape at intra- and interspecific levels were analyzed in 108 Hg. capricornii and Hg. janthinomys females. RESULTS: Geometric morphometry indicated size and shape variables can differentiate these species at interspecific level. However, at intraspecific level, results show relative differentiation. Two populations of Hg. capricornii had a smaller centroid size with no significant differences between them, whereas all Hg. janthinomys populations showed significant differences. CONCLUSIONS: Both species were correctly identified by geometric morphometry.

Distribution of Haemagogus and Sabethes Species in Relation to Forest Cover and Climatic Factors in the Chapada Dos Guimarães National Park, State of Mato Grosso, Brazil.

Members of the genera Haemagogus and Sabethes are the most important biological vectors of the wild yellow fever virus (WYF) in the forested areas of the Americas. The ecologies of Haemagogus janthinomys, Hg. leucocelaenus, Sabethes chloropterus, and Sa. glaucodaemon were studied in a forest of the Chapada dos Guimarães National Park, state of Mato Grosso, Brazil, to evaluate the influence of climatic factors (temperature and relative humidity [RH]) on their abundance. We also examined the association of climate with landscape structure on species distribution patterns throughout the seasons of the year. Multiple stepwise regressions showed that RH was most likely to influence the density of mosquito populations. A multidimensional scaling (MDS) was used to evaluate the effects of forest cover on the composition of mosquito populations at different radii (100-, 250-, and 1,000-m-radius buffer areas). The MDS provided 2 dimensions with values that indicated a higher similarity in the composition of culicid populations between sites 1 and 3, while site 2 was separate from the others in the ordination space. Site 2 had a much higher forest cover ratio at 100-m radius compared with sites 1 and 3. We found a possible relationship between the forest cover and the composition of the mosquito populations only in the 100-m radius. These results enabled us to infer that RH directly favored the activity of mosquito populations and that the forest cover located closest to the sampling site may influence the species composition. Since mosquito abundance was higher in the sites with lower local forest cover, forest fragmentation may be a key factor on the presence of WYF vector.

Diversity of yellow fever mosquito vectors in the Atlantic Forest of Rio de Janeiro, Brazil.

INTRODUCTION: Environmental modifications caused by human activities have led to changes in mosquito vector populations, and sylvatic species have adapted to breeding in urban areas. METHODS: Mosquitoes were collected using ovitraps in three sampling sites in the Atlantic Forest in the State of Rio de Janeiro, Brazil. RESULTS: We collected 2,162 Culicidae specimens. Haemagogus janthinomys and Haemagogus leucocelaenus, both sylvatic yellow fever virus vectors, were the most common species found. CONCLUSION: There is a potential for the transmission of arboviruses in and around these natural reserves. Therefore, it is necessary to maintain entomological surveillance programs in the region.

Morphological differentiation between seven Brazilian populations of Haemagogus capricornii and Hg. janthinomys (Diptera: Culicidae) using geometric morphometry of the wings

Abstract INTRODUCTION: Haemagogus capricornii and Hg. janthinomys females are considered morphologically indistinguishable. We analyzed morphometric variability between Brazilian populations of these species using wing geometric morphometry. METHODS: Size and shape at intra- and interspecific levels were analyzed in 108 Hg. capricornii and Hg. janthinomys females. RESULTS: Geometric morphometry indicated size and shape variables can differentiate these species at interspecific level. However, at intraspecific level, results show relative differentiation. Two populations of Hg. capricornii had a smaller centroid size with no significant differences between them, whereas all Hg. janthinomys populations showed significant differences. CONCLUSIONS: Both species were correctly identified by geometric morphometry.

Immature mosquitoes (Diptera: Culicidae) in a eutrophic landfill tank from State of Rio de Janeiro, Brazil.

INTRODUCTION: To determine the faunal composition of immature culicids inhabiting a percolation tank in the landfill of Sapucaia, State of Rio de Janeiro, Brazil, immature mosquitoes were collected over a two-day period during the third weeks of April, August and October 2011. RESULTS: The species found were Culex usquatus, Lutzia bigoti, Anopheles argyritarsis and Limatus durhamii. This study is the first to report the colonization of eutrophic breeding sites by these species. CONCLUSIONS: The oviposition behavior observed in this study suggests a secondary adaptation or change in habit to select eutrophic environments during the developmental stages of the observed species.