Zika virus (ZIKV) was recently introduced into the Western Hemisphere, where it is suspected to be transmitted mainly by Aedes aegypti in urban environments. ZIKV represents a public health problem as it has been implicated in congenital microcephaly in South America since 2015. Reports of ZIKV transmission in forested areas of Africa raises the possibility of its dispersal to non-human-modified environments in South America, where it is now endemic. The current study aimed to detect arboviruses in mosquitoes collected from areas with low human interference in Rio de Janeiro, Brazil. Using a sensitive pan-flavivirus RT-PCR, designed to detect the NS5 region, pools of Ae. albopictus and Haemagogus leucocelaenus, were positive for both ZIKV and yellow fever (YFV). Virus RNA was detected in pools of adult males and females reared from field-collected eggs. Findings presented here suggest natural vertical transmission and infection of ZIKV in Hg. leucocelaenus and Ae.albopitcus in Brazil.

During a medical entomology course in Boa Vista, Roraima, colonies of Triatoma maculata closely associated with pigeon nests were observed in concrete air-conditioner box located on the external plastered and cemented walls of a modern brick-built apartment block. In only one eight-hole ceramic brick, located inside one air-conditioner box, 127 specimens of T. maculata were collected. T. maculata is a recognised vector of Trypanosoma cruzi in the surrounding area and its domiciliation increases the risk of Chagas disease transmission.

Living bamboo stalks are one of the most specialized habitats for mosquito oviposition and immature development. Most of the mosquito species that breed in these habitats are sylvatic, and some are of importance for public health as possible vectors of pathogens. Perforated internodes are a very specialized environment due to the difficulty of access. Furthermore, due to their relatively simple fauna, they represent a valuable model for ecological studies that may be applicable to more complex environments. This study aims to assess the mosquito bionomics of species raised in bamboo internodes. Therefore, the diversity of mosquito species and the influence of abiotic variables (pH and temperature) on the distribution of mosquitoes that breed in this habitat were analyzed. The study area is a fragment of Atlantic Forest within the Association of da Armada (ATA) in Nova Iguaçu, state of Rio de Janeiro, Brazil. Immature mosquitoes were sampled with suction tubes (mouth aspirators) between August 2017 and July 2018. A total of 3,170 larvae were collected in 5 bamboo plants, each with 8 stalks perforated. Of these, 688 larvae reached the adult stage, representing 10 genera and 19 species. The most common species were Culex neglectus (43%), Trichoprosopon digitatum (22%), Culex iridescens (8%), Sabethes identicus (7%), and Orthopodomyia albicosta (7%). The richness of the immatures collected in the ATA was 19 species, with a diversity of 1.10 and Shannon evenness of 0.57. A diverse composition of Culicidae in bamboo stalks was found, although dominance was low.

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.