Experimental releases of female Aedes (Stegomyia) aegypti and Aedes (Stegomyia) albopictus were performed in August and September 1999, in

Dengue fever is an acute, mosquito-transmitted viral disease caused by any of four virus serotypes (DEN-1, DEN-2, DEN-3 and DEN-4). Nowadays dengue is the most important human disease caused by arbovirus in the world. Its incidence has increased in tropical areas where the main vector Aedes aegypti (Linnaeus) has spread due to unplanned urbanization and lack of effective control (Gubler & Clark 1996).In the last 16 years in Brazil an increase in the frequency of epidemics and the geographic expansion of both the mosquito vector and the viruses resulted in the co-circulation of DEN-1 and DEN-2 viruses in 25 out of 27 Brazilian states (Nogueira et al. 1999, Funasa 2001.In the municipality of Nova Iguaçu, located in the Metropolitan Region of the State of Rio de Janeiro, dengue cases have been reported since DEN-1 virus was isolated for the first time in the State (Schatzmayr et al. 1986, Miagostovich et al. 1993. By the end of December 2000, DEN-3 virus was first isolated from an autochthonous case of dengue fever (Nogueira et al. 2001) when the house infestation levels of Ae. aegypti and Ae. albopictus were 8.1% and 4.5%, respectively (WC Silva, pers. commun.). Braga et al. (2000) observed that local samples of Ae. aegypti presented 58% of resistance to temephos.The high dengue viruses activity in Nova Iguaçu stimulated a series of field studies aiming to elucidate several aspects of dengue vectors' biology started in 1997 (Honório 1999, Honório & Lourenço-de-Oliveira 2001 cal surveillance has been carried out for the detection of dengue virus from field collected Ae. aegypti and Ae. albopictus (Skuse). From July 2000 to June 2001 adult mosquitoes were caught in 35 districts of that municipality. The captures were performed twice a week, alternately in the morning and in the afternoon, with manual and battery backpack aspirators and with nets, both indoors and in the yards and gardens, close to the dwellings. Mosquitoes were captured while flying, seeking for blood or hiding in resting places. Mosquitoes were identified to species, pooled according to sex, date, district and stored in liquid N 2 at the same day of collection.From a total of 2,164 mosquitoes, 503 Ae. aegypti (352 females + 151 males) and 80 Ae. albopictus (58 + 22) were pooled (9-17 mosquitoes/pool) and processed for virus isolation. Briefly, mosquito pools were grounded in 1 ml of Leibovitz L-15 (Gibco BRL, Life Technologies) tissue culture medium and centrifuged for 15 min at 6,000 rpm. After treatment with penicilin-streptomicin -10,000 units -(Gibco BRL, Life Technologies) 50 µl of the supernatants were inoculated into the monolayer of Ae. albopictus clone C6/ 36 cell line (Igarashi 1978) supplemented with 2% fetal bovine sera (Gibco BRL, Life Technologies), 1% non-essential amino-acids (Gibco BRL, Life Technologies) and 10% tryptose phosphate broth (Gibco BRL, Life Technologies). Culture tubes were kept at 28ºC and daily observed up to 10 days. Immunofluorescence assays with serotype specific monoclonal antibodies were carried out to detect a...

BACKGROUND Southeast Brazil has recently experienced a Yellow Fever virus (YFV) outbreak where the mosquito Haemagogus leucocelaenus was a primary vector. Climatic factors influence the abundance of mosquito vectors and arbovirus transmission. OBJECTIVES We aimed at describing the population dynamics of Hg. leucocelaenus in a county touched by the recent YFV outbreak. METHODS Fortnightly egg collections with ovitraps were performed from November 2012 to February 2017 in a forest in Nova Iguaçu, Rio de Janeiro, Brazil. The effects of mean temperature and rainfall on the Hg. leucocelaenus population dynamics were explored. FINDINGS Hg. leucocelaenus eggs were continuously collected throughout the study, with a peak in the warmer months (December-March). The climatic variables had a time-lagged effect and four weeks before sampling was the best predictor for the positivity of ovitraps and total number of eggs collected. The probability of finding > 50% positive ovitraps increased when the mean temperature was above 24ºC. The number of Hg. leucocelaenus eggs expressively increase when the mean temperature and accumulated precipitation surpassed 27ºC and 100 mm, respectively, although the effect of rainfall was less pronounced. MAIN CONCLUSIONS Monitoring population dynamics of Hg. leucocelaenus and climatic factors in YFV risk areas, especially mean temperature, may assist in developing climate-based surveillance procedures to timely strengthening prophylaxis and control.

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.

ABSTRACT. In order to gather information on the culicid fauna of Nova Iguaçu Municipal Park, Rio de Janeiro, Brazil, adult and immature stages were collected with the Centers for Disease Control and Prevention miniature light traps, and dippers and suction tubes, respectively. In all, 828 adult and 990 immature specimens were collected belonging to 12 genera. Among the species collected were Aedes aegypti, Ae. albopictus, Ae. fluviatilis, Ae. scapularis, Haemagogus leucocelaenus, and Psorophora ferox that are considered of potential medical importance. Culicids used a variety of larval habitats and bred under diverse ecological conditions, mostly in natural water containers formed by bamboo, bromeliad, ground depression, rock pool, stream, tree hole, and in artificial containers such as abandoned bathtub, car carcass, abandoned sink, plastic cup, waste tire, and water tank. Species richness and diversity increased from lower to higher forest cover and was highest in sites with highest diversity and high number of larval habitats.