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The present study aims to analyze the effectiveness of ovitraps in the capture of Hg leucocelaenus eggs and evaluate the influence of the dry and rainy seasons on their abundance and hatching rates. The eggs were collected in the Atlantic Forest of State of Rio de Janeiro, Brazil, an area in which the yellow fever virus is known to circulate. We distributed 15 ovitraps in three sampling points, with five ovitraps per point. We distributed 15 ovitraps in three sampling points on trees within a forested area, which were sequentially numbered, monitored, and replaced every two weeks from October 2016 to April 2018. There was a high dominance of Hg. leucocelaenus eggs (98.4%) and a variation in egg hatching rates between the wet and dry seasons. These rates were 1.5 times higher in the rainy season than in the dry season. The rainy season also showed a greater abundance of eggs and higher values of ovitrap positivity and egg density indexes in the installed ovitraps. The abundances of Hg. leucocelaenus eggs were positively correlated with mean monthly temperature and air humidity but not significantly correlated with accumulated precipitation. These results, as well as their implications for the possible use of ovitraps to monitor vector mosquitoes of yellow fever in the study region, are discussed. [ABSTRACT FROM AUTHOR]

Background: Mosquito assemblages are organized along an ecological gradient, including small habitats where interspecific competition predominates and large permanent habitats where predation predominates. This study aimed to analyze the oviposition behavior of mosquitoes regarding the preference for traps installed at two different heights with regard to ground level and the tendency to share spawning sites in an Atlantic Forest fragment in Nova Iguaçu, State of Rio de Janeiro, Brazil. Methods: The eggs were collected from April 2018 to March 2019. Twelve ovitraps were used, randomly distributed in trees at ground level and at a height of 3 m in a forest environment. Results: They were sequentially numbered, monitored, and replaced every 2 weeks. Among the 5818 eggs collected, 3941 hatched, 3756 reached the pupa stage, and 2370 reached the adult stage. The most abundant species were Aedes albopictus (63%) and Haemagogus leucocelaenus (35%), followed by Aedes terrens (2%) and Haemagogus janthinomys (1%). Analyses showed a significant difference of (P = 0.02) between the number of mosquito species collected in the palettes at ground level and the number collected at the height of 3 m. Cluster analysis of species abundance showed that the eggs collected in the palettes at ground level were more abundant than those collected in the palettes at the height of 3 m. We detected co-occurrence of species in the oviposition palettes; according to the null model, such species distribution was not random. Conclusions: The exploitation of oviposition sites by mosquito species can represent an event forced by population density facilitated by the ecological valence of individuals of one species. Understanding the aggregate distribution of larvae at the oviposition site allows us to conduct more in-depth studies of the oviposition behavior of female mosquitoes. [ABSTRACT FROM AUTHOR]

Understanding mosquito biodiversity in the Atlantic Forest is important for assessing changes in the distribution of mosquito populations, which have been considered predominantly to be sylvatic. An observational study of Culicidae was conducted in a remnant of the Atlantic Forest in the Poço das Antas Biological Reserve, Silva Jardim municipality, Rio de Janeiro state, Brazil, to evaluate species diversity and the influence of climatic factors (temperature, relative humidity and rainfall) on species distribution. Two types of light trap were used: an automatic CDC trap baited with CO2 and a Shannon trap. Collections were also made using a manual suction tube. Overall, 15 700 Culicidae specimens were collected belonging to two subfamilies, 12 genera and 41 species. The most common species were Coquillettidia chrysonotum, Mansonia titillans and Coquillettidia venezuelensis. Principal component analyses indicated a major association between sampling site six and the species Anopheles albitarsis, Mansonia titilllans, Cq. chrysonotum and Cq. venezuelensis. Furthermore, diversity indices indicated that sampling sites 1, 6 and 4 displayed higher diversity and a more uniform species abundance. Culicidae abundance was positively correlated with temperature. Landscape units exhibited contrasting community compositions of mosquitoes at multiple scales, with the community composition more similar in sites with similar landscape parameters. The importance of constant entomological monitoring is underscored by the diversity of mosquito species in this reserve and their potential role in the transmission of pathogens, combined with intermittent flow of visitors to the area. [ABSTRACT FROM AUTHOR]