Search Results (3)

Phytotelmata are aquatic microenvironments formed by the accumulation of water and organic matter in cavities of plants. These microenvironments serve as breeding sites for various species of mosquitoes, including some of epidemiological importance. Our objective was to identify the mosquito fauna in these microenvironments and to analyze variations in mosquito fauna diversity between bromeliads, tree holes, and bamboo internodes in Cantareira State Park, São Paulo (CSP), Brazil, where there have been reports of yellow-fever epizootics in non-human primates and circulation of plasmodia. Collections were carried out monthly from February 2015 to April 2017. The bromeliads showed greater mosquito species richness and diversity than the tree holes and bamboo internodes, as well as a very different composition. Of the 11 genera collected and 49 taxa identified, Culex (Carrolia) iridescens, Cx. ocellatus, Cx. (Microculex) imitator, and Anopheles (Kerteszia) cruzii were the most abundant. The phytotelmata in the CSP showed significant differences in species richness, diversity, and composition and were found to support a diverse mosquito fauna to develop, including An. cruzii and the sylvatic yellow fever virus vector Haemagogus leucocelaenus. The finding of these epidemiologically important species highlights the key role played by phytotelma breeding sites as places of refuge and species maintenance for these vectors in green areas close to urban centers. Full article

Sylvatic yellow fever (SYF) was recently a health issue in Brazil (2016–2019) because transmission was facilitated by a high density of vectors, amplifying hosts, and low vaccine coverage of the human population, especially in urban forests in the Southeast Region of Brazil. Moreover, urban forest edges are more likely to have contact between human and sylvatic vector mosquito populations. Here, we show the association between abiotic and biotic features of tree holes as Haemagogus leucocelaenus rearing sites in Cantareira State Park in Atlantic Forest edges. The analyzed physical features of the tree holes were diameter at breast height, tree hole opening diameter, depth, trunk diameter, tree hole volume, collected volume, height (varying from 0.02 to 4.2 m above ground), and the presence of Culicidae species other than Hg. leucocelaenus. We analyzed 105 positive and 68 negative water samples for larval presence and found no differences between them, suggesting the lack of specific physical characteristics in these categories. Hg. leucocelaenus larval abundance was correlated with the collected volume and opening diameter of tree holes. The tree species that most represented negative breeding sites were Euplassa cantareirae, Guarea macrophylla, Psychotria suterella, and Tibouchina pulchra. Four significant clusters as areas with a high risk of SYV were identified by Get-Ordis spatial analysis. Although Hg. leucocelaenus larvae were found in tree holes with high water levels, their occurrence was regulated by that of other mosquito species. Our findings contribute to clarifying immature vector ecology in tree holes related to human exposure to SYF in urban forest edges. Full article

Hand-held insect nets are the standard method for capturing vector mosquitoes of sylvatic arboviruses; however, occupational risks and biases due to individual skill and attractiveness are important limitations. The use of chemical attractants and automatic traps could be an alternative to resolve these limitations. This study compares the yields achieved using nets with those employing electrical traps with CO₂ and BG-Lure^®, near the ground and in the canopy strata (6.0 and 8.0 m high). The study was conducted at the Cantareira State Park, which is in the Brazilian Atlantic Forest biome. In the 18 collections performed, 3570 specimens of 52 taxa were obtained. The most frequent species captured near the ground were Wyeomyia confusa and Limatus durhamii, whereas Sabethes albiprivus, Sabethes purpureus, and Haemagogus leucocelaenus were the most frequent in the canopy. The nets resulted in greater species richness and abundance, followed by the trap employing CO₂. The combination of CO₂ traps with BG-Lure^® did not improve performance. The use of BG-Lure^® alone resulted in low abundance and a low number of species. Our results demonstrate that the use of traps with CO₂ can be complementary to collections with nets; however, for species of epidemiological interest such as those of the genera Haemagogus and Sabethes, especially in the canopy, the net remains the method of choice. Full article