Composition and diversity of mosquitoes (Diptera: Culicidae) in urban parks in the South region of the city of São Paulo, Brazil

Abstract

Abstract Many parks in the city of São Paulo contain remnants of Atlantic Forest. Of the 30 municipal parks in the South of the city, we investigated two in this study (Santo Dias Park and Shangrilá Park) in order to survey their mosquito fauna and investigate the presence of potential bioindicators of environmental conditions and vectors of human pathogens. Mosquitoes were collected monthly between March 2011 and February 2012 using aspirators, Shannon and CDC traps for adult mosquitoes and larval dippers and suction samplers for immature forms. Sampling effort was evaluated by plotting a species accumulation curve, and total richness was estimated using the first-order jackknife. To compare the diversity between the two parks Shannon and Simpson diversity indexes were calculated. Species similarity was compared by the Sorensen similarity index. In all, 8,850 specimens were sampled in both parks. Collections in Santo Dias Park yielded 1,577 adult mosquitoes and 658 immature individuals distributed in seven genera (Aedes, Anopheles, Culex, Limatus, Mansonia, Toxorhynchites and Wyeomyia) and 27 taxonomic units. Among the adult mosquitoes collected, Culex nigripalpus .and Aedes fluviatilis were the most abundant, while the most abundant immature forms were Cx. imitator, Wy. davisi, Wy. galvaoi and Ae. albopictus. Collections in Shangrilá Park yielded 4,952 adult specimens and 1,663 immature forms distributed in eight genera (Aedes, Anopheles, Culex, Limatus, Mansonia, Toxorhynchites, Uranotaenia and Wyeomyia) and 36 taxonomic units. Species accumulation curves in both parks were close to the asymptote, and the total richness estimate was close to the observed richness. Although the observed species richness was higher in the Shangrilá Park, there was no statistically significant difference between the diversity indexes measured. Regarding species composition, the two sites shared 16 species, including those of epidemiological importance such as Culex nigripalpus, Cx. quinquefasciatus, Aedes albopictus and Ae. aegypti. As some of the mosquito taxa found are bioindicators of environmental conditions and have epidemiological potential to carry pathogens, we recommend that urban parks should be included in official mosquito surveillance programs, and regular surveys carried out to detect circulating arboviruses.