Mosquito (Diptera: Culicidae) diversity along a rainy season and edge effects in a riparian forest in Southeastern Brazil

Abstract

Knowledge on the distribution of mosquito communities over time and across human‐modified landscapes is important in determining the risk for vector‐borne disease. The diversity of mosquitoes along a rainy season and edge effects were evaluated in a riparian forest in the Cerrado biome, Southeastern Brazil. Mosquito communities were sampled with Shannon traps in three distinct habitats (forest interior, forest edge and pasture) throughout an entire rainy season, comprising five sampling months (December 2015 to April 2016). A total of 13 549 mosquitoes belonging to 54 species were sampled. Mosquito species richness and abundance were greater in February, which coincided with the middle of the rainy season and just after the months with greater rainfall. Mosquito species richness did not differ among habitats for any particular month. In February, month when 74% of individuals were recorded, mosquito abundance was lower in the pasture compared with the forest edge and interior, which did not differ statistically from each other. Four of the six most abundant mosquito species (which account for 93.5% of the sampled individuals) had more individuals collected in the forest edge, and 28 species were more abundant at the edge compared with 15 species in the forest interior. Months with high rainfall probably allowed the availability and maintenance of high‐water level in breeding sites leading to a further increase in mosquito populations. While the pasture did not seem to have the ideal abiotic conditions and/or resources (e.g. food and breeding sites) for mosquito species, edge effects appear to favour mosquito populations. Therefore, the risk of mosquito‐borne diseases is expected to be greater in the middle of the rain season at the riparian forest‐pasture edge, when and where a greater number of disease‐vectoring species are present.

Forest edge landscape context affects mosquito community composition and risk of pathogen emergence

“…We also found that species evenness was slightly, but significantly lower during the rainy season compared to the dry season. While higher diversity is generally associated with rainy months 11 , our findings may reflect an increased dominance of Hg. janthinomys , Ps.…”

“…Rural edges also appear to enhance permeability for sylvatic vectors 8 and inevitably their pathogens. Studies failing to detect higher diversity at forest edges have often restricted sampling to within a few hundred meters of the boundary [9][10][11]59 , yet we have only detected substantially lower diversity when sampling beyond 500 m into the forest 17,18 . We also found that species evenness was slightly, but significantly lower during the rainy season compared to the dry season.…”

“…Forest edges, where humans, mosquitoes, and wildlife overlap may serve as a nexus for zoonotic arbovirus exchange 8 . Studies have investigated shifts in mosquito communities [9][10][11][12] and wildlife [13][14][15] from interior forest to forest edge, and then to human-modified landscapes. Despite suggestions that mosquito diversity should peak in edge habitats 10 , where urban and sylvatic species overlap, empirical studies have not consistently found highest diversity at edges 9,10,16,17 .…”

Diversity patterns along ecological succession in tropical dry forests: a multi‐taxonomic approach

“…Although culicid species respond differently to deforestation, disease‐vector mosquitoes usually are positively affected by anthropogenic impacts (Burkett‐Cadena and Vittor 2018). The high abundance of mosquitoes in the early succession areas can be attributed to floodwater species such as Aedes scapularis and Psorophora (Ferreira et al 2016), which dramatically proliferate during the rainy season (Costa et al 2023). These species breed in ponds on the ground and prefer open vegetation areas where the increased amount of sunlight stimulates algae growth, and herbaceous plants provide nectar for adult mosquitoes.…”