Fauna and Virological Investigation of Mosquitoes in Urban Parks in Sã;o Paulo, Brazil.

The mosquito fauna in urban parks in the city of São Paulo, Brazil, was investigated and compared for richness and diversity, and the abundance of each species was associated with climatic variables. Simultaneously, a virological investigation was performed to test the presence of Flavivirus and Alphavirus. Aspirations of adult mosquitoes were conducted in 3 urban parks for 3 consecutive weeks of each season between October 2018 and January 2020. A total of 2,388 mosquitoes were identified, with Culex quinquefasciatus, Cx. nigripalpus, and Aedes aegypti being the most abundant species. Mosquito assemblages showed similar richness and diversity, showing variability in individual results. Temperatures and Ae. aegypti abundance correlated significantly in one of the parks investigated herein. Urban parks represent areas of shelter and refuge for both anthropophilic and opportunistic species, such as Cx. quinquefasciatus and Ae. aegypti, as well as species that still need moderately preserved environments to develop.

Reemergence of Yellow Fever in Brazil: The Role of Distinct Landscape Fragmentation Thresholds.

Yellow Fever Virus (YFV) reemergence in Brazil was followed by human suffering and the loss of biodiversity of neotropical simians on the Atlantic coast. The underlying mechanisms were investigated with special focus on distinct landscape fragmentation thresholds in the affected municipalities. An ecological study in epidemiology is employed to assess the statistical relationship between events of YFV and forest fragmentation in municipal landscapes. Negative binomial regression model showed that highly fragmented forest cover was associated with an 85% increase of events of YFV in humans and simians (RR = 1.85, CI 95% = 1.24-2.75, p=0.003) adjusted by vaccine coverage, population size, and municipality area. Intermediate levels of forest cover combined with higher levels of forest edge densities contribute to the YFV dispersion and the exponential growth of YF cases. Strategies for forest conservation are necessary for the control and prevention of YF and other zoonotic diseases that can spillover from the fragmented forest remains to populated cities of the Brazilian Atlantic coast.

Diversity and abundance of mosquitoes (Diptera:Culicidae) in an urban park: larval habitats and temporal variation.

Urban parks are areas designated for human recreation but also serve as shelter and refuge for populations of several species of native fauna, both migratory and introduced. In Brazil, the effect of annual climate variations on Aedes aegypti and dengue epidemics in large cities like São Paulo is well known, but little is known about how such variations can affect the diversity of mosquito vectors in urban parks and the risk of disease transmission by these vectors. This study investigates the influence of larval habitats and seasonal factors on the diversity and abundance of Culicidae fauna in Anhanguera Park, one of the largest remaining green areas in the city of São Paulo. Species composition and richness and larval habitats were identified. Seasonality (cold-dry and hot-rainy periods) and year were considered as explanatory variables and the models selection approach was developed to investigate the relationship of these variables with mosquito diversity and abundance. A total of 11,036 specimens from 57 taxa distributed in 13 genera were collected. Culex nigripalpus, Cx. quinquefasciatus and Aedes albopictus were the most abundant species. Bamboo internodes and artificial breeding sites showed higher abundance, while ponds and puddles showed greater richness. Significant relationships were observed between abundance and seasonality, with a notable increase in the mosquitos abundance in the warm-rainy periods. The Shannon and Berger-Parker indices were related with interaction between seasonality and year, however separately these predictors showed no relationship with ones. The increased abundance of mosquitoes in warm-rainy months and the fact that some of the species are epidemiologically important increase not only the risk of pathogen transmission to people who frequent urban parks but also the nuisance represented by insect bites. The findings of this study highlight the importance of knowledge of culicid ecology in green areas in urban environments.

Immature mosquitoes in bamboo internodes in municipal parks, city of são paulo, Brazil.

We conducted an inventory of the mosquito fauna of the internodes of bamboo plants grown in municipal parks in the city of São Paulo, Brazil. During October 2010 to July 2013, a total of 8,541 immature stages belonging to 21 mosquito species were collected from bamboos over 61 municipal parks. Of these, Aedes albopictus was the most abundant species followed by Ae. aegypti found in broken bamboos in most parks. The former species was 7.2 times more abundant than the latter when both species shared the same habitat. Other species collected from bamboos included Culex quinquefasciatus and Haemagogus leucocelaenus. In bamboos with perforated internodes, species of the genus Wyeomyia were the most prevalent. Differences were also observed in species composition and abundance of mosquitoes collected in transversely broken bamboos and those collected from perforated bamboo internodes. Constant surveillance of these breeding sites is crucial due to the epidemiological importance of the species found. Furthermore, these breeding sites may help maintain some native wild mosquito populations along with a variety of other invertebrates found in these urban green areas.