Mosquito community composition in South Africa and some neighboring countries

Abstract

BackgroundA century of studies have described particular aspects of relatively few mosquito species in southern Africa, mostly those species involved with disease transmission, specifically malaria and arboviruses. Patterns of community composition such as mosquito abundance and species diversity are often useful measures for medical entomologists to guide broader insights and projections regarding disease dynamics and potential introduction, spread or maintenance of globally spreading pathogens. However, little research has addressed these indicators in southern Africa.ResultsWe collected 7882 mosquitoes from net and light traps at 11 localities comprising 66 species in 8 genera. We collected an additional 8 species using supplementary collection techniques such as larval sampling, sweep-netting and indoor pyrethrum knockdown catches. Highest diversity and species richness was found in the Okavango Delta of Botswana and in South Africa’s Kruger National Park, while the lowest diversity and abundances were in the extreme southern tip of South Africa and in semi-desert Kalahari close to the South Africa border with Botswana. Species composition was more similar between proximal localities than distant ones (Linear model P-value = 0.005). Multiple arbovirus vector species were detected in all localities we surveyed (proportion of vector mosquito numbers were > 0.5 in all locations except Shingwedzi). Their proportions were highest (> 90%) in Vilankulo and Kogelberg.ConclusionsMultiple known arbovirus vector species were found in all study sites, whereas anopheline human malaria vector species in only some sites. The combination of net traps and light traps effectively sampled mosquito species attracted to carbon-dioxide or light, accounting for 89% of the 74 species collected. The 11% remaining species were collected using supplementary collection techniques mentioned above. The diversity of species weas highest in savanna type habitats, whereas low diversities were found in the drier Kalahari sands regions and the southern Cape fynbos regions.Electronic supplementary materialThe online version of this article (10.1186/s13071-018-2824-6) contains supplementary material, which is available to authorized users.

A comparative assessment of adult mosquito trapping methods to estimate spatial patterns of abundance and community composition in southern Africa

“…1; between 22°31' and 25°31'S, 30°45' and 32°00'E). We focus on KNP because it is a hotspot of mosquito diversity [15], it is in a region of southern Africa with regular outbreaks of mosquitoborne disease (e.g. [34,35]), and it includes a sentinel site for mosquitoes and pathogen surveillance [36]).…”

“…We trapped at each site within a region for four consecutive nights and moved sequentially between Germany), the Biogents gravid Aedes trap (Biogents AG) and the net trap. Although the net trap is not commercially available, it is easily and inexpensively made from netting and poles (see [15,31]). For consistency in sampling, we set up the traps at a similar distance away from the water body Our trap-use protocol was based on preliminary trapping work and expertise from mosquito surveillance in southern Africa [15,31].…”

“…Although the net trap is not commercially available, it is easily and inexpensively made from netting and poles (see [15,31]). For consistency in sampling, we set up the traps at a similar distance away from the water body Our trap-use protocol was based on preliminary trapping work and expertise from mosquito surveillance in southern Africa [15,31]. Specifically, we equipped the CDC trap, BG trap and net trap with a closed container containing 200-400 g of dry ice for a CO2 bait.…”

“…Previous work has characterized the distribution [28], ecological drivers [29] and consequences for malaria risk [30] of key anopheline species. Understanding the distribution and drivers of non-Anophelinae mosquito species in southern Africa could facilitate informed management of a broader range of mosquito-borne disease or the development of vector control programmes that target multiple infections [15,31].…”

“…entomological surveys, pathogen surveillance or invasive/nuisance mosquito species control) we compared traps designed for a range of purposes with a range or attraction methods. We assessed the Centers for Disease Control miniature light trap (CDC) and a net trap due to their historic success for entomological surveys in a range of systems in southern Africa [9,15,16]. These traps use incandescent light + CO2 and CO2, respectively, to attract host-seeking vectors.…”