Mosquito communities and disease risk influenced by land use change and seasonality in the Australian tropics

Abstract

BackgroundAnthropogenic land use changes have contributed considerably to the rise of emerging and re-emerging mosquito-borne diseases. These diseases appear to be increasing as a result of the novel juxtapositions of habitats and species that can result in new interchanges of vectors, diseases and hosts. We studied whether the mosquito community structure varied between habitats and seasons and whether known disease vectors displayed habitat preferences in tropical Australia.MethodsUsing CDC model 512 traps, adult mosquitoes were sampled across an anthropogenic disturbance gradient of grassland, rainforest edge and rainforest interior habitats, in both the wet and dry seasons. Nonmetric multidimensional scaling (NMS) ordinations were applied to examine major gradients in the composition of mosquito and vector communities.ResultsWe captured ~13,000 mosquitoes from 288 trap nights across four study sites. A community analysis identified 29 species from 7 genera. Even though mosquito abundance and richness were similar between the three habitats, the community composition varied significantly in response to habitat type. The mosquito community in rainforest interiors was distinctly different to the community in grasslands, whereas forest edges acted as an ecotone with shared communities from both forest interiors and grasslands. We found two community patterns that will influence disease risk at out study sites, first, that disease vectoring mosquito species occurred all year round. Secondly, that anthropogenic grasslands adjacent to rainforests may increase the probability of novel disease transmission through changes to the vector community on rainforest edges, as most disease transmitting species predominantly occurred in grasslands.ConclusionOur results indicate that the strong influence of anthropogenic land use change on mosquito communities could have potential implications for pathogen transmission to humans and wildlife.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1675-2) contains supplementary material, which is available to authorized users.

Experimental logging alters the abundance and community composition of ovipositing mosquitoes in the southern Appalachians

“…3), there were no significant effects of logging treatment on either univariate diversity metric. These results differ from previous studies in Peru, Thailand, and Australia, which found strong declines in mosquito community diversity in more urbanised landscapes (Johnson et al, 2008;Thongsripong et al, 2013;Meyer Steiger et al, 2016). Because our study specifically isolated the effects of logging, it is possible that other characteristics of urbanisation explain the previously detected, much stronger, decreases in community diversity across a broad degradation or urbanisation gradient.…”

“…On the other hand, lack of logging effects on mosquito diversity may be largely an artifact of the sampling methods we used. Previous studies that found effects of urbanisation on mosquito diversity (Johnson et al ., ; Thongsripong et al ., ; Meyer Steiger et al ., ) used traps that were selective for host‐seeking mosquitoes (e.g. light traps, BG sentinel), whereas this study used gravid traps, which were selective for ovipositing females.…”

“…The influence of logging per se on adult mosquito communities has not yet been directly examined, but several prior studies have examined how urbanisation or land‐use gradients, which integrate a suite of landscape changes including loss of intact forest, influence adult mosquito communities. Studies of land‐use gradients in the Peruvian Amazon (Johnson et al ., ), Thailand (Thongsripong et al ., ), Spain (Ferraguti et al ., ), Madagascar (Zhody et al ., ), and remote Australian islands (Meyer Steiger et al ., ) generally find the highest mosquito abundance and diversity in rural, forested sites with high vegetative cover relative to more urban habitats. However, in Anopheles species, the combined effects of deforestation and conversion to agriculture are highly species‐specific, with some taxa increasing in abundance with land‐use change, and others decreasing (Yasuoka & Levins, ).…”

“…Although the impacts of deforestation on vector ecology and resulting disease risk have been of long-standing interest (reviewed in Walsh et al, 1993), only recently have studies explicitly considered how anthropogenic changes to intact forests alter the diversity and abundance of the invertebrate taxa that commonly serve as disease vectors (e.g. Thongsripong et al, 2013;Meyer Steiger et al, 2016;Zhody et al, 2016).…”

Forest disturbance and vector transmitted diseases in the lowland tropical rainforest of central Panama

“…Meyer Steiger et al . reported more mosquito species capable of transmitting pathogens to humans in grasslands than in pristine forest habitats, further showing that anthropogenic landscape changes could have implications for disease spill over. Alroy further suggested that this bimodal trend in mosquito species diversity and abundance at the opposite extremes of the disturbance gradient is probably due to the invasion of colonist species adapted to open habitats, transiently increasing the size of the species pool in disturbed forest scenarios.…”