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

Abstract

Background: Assessing adult mosquito populations is an important component of disease surveillance programs and ecosystem health assessments. Inference from adult trapping datasets involves comparing populations across space and time, but comparisons based on different trapping methods may be biased if traps have different efficiencies or sample different subsets of the mosquito community. Methods:We compared four widely-used trapping methods for adult mosquito data collection in Kruger National Park (KNP), South Africa: Centers for Disease Control miniature light trap (CDC), Biogents Sentinel trap (BG), Biogents gravid Aedes trap (GAT) and a net trap. We quantified how trap choice and sampling effort influence inferences on the regional distribution of mosquito abundance, richness and community composition. Results:The CDC and net traps together collected 96% (47% and 49% individually) of the 955 female mosquitoes sampled and 100% (85% and 78% individually) of the 40 species or species complexes identified. The CDC and net trap also identified similar regional patterns of community composition. However, inference on the regional patterns of abundance differed between these traps because mosquito abundance in the net trap was influenced by variation in weather conditions. The BG and GAT traps collected significantly fewer mosquitoes, limiting regional comparisons of abundance and community composition. Conclusions:This study represents the first systematic assessment of trapping methods in natural savanna ecosystems in southern Africa. We recommend the CDC trap or the net trap for future monitoring and surveillance programs.

A Network Perspective on the Vectoring of Human Disease

“…In particular, collection methods that use live hosts, such as human landing catches [77], will be heavily biased [78]. Widely-used and efficient insect sampling methods include USA Centre for Disease Control (CDC) miniature light traps and BGS traps with CO2 bait, which capture a wide range of mosquitos [79], sand flies [80] and biting midges [81,82]. We recommend using a combination of sampling methods to maximise representation of the biting insect fauna.…”

How Does eDNA Compare to Traditional Trapping? Detecting Mosquito Communities in South-African Freshwater Ponds

“…Using a variety of trapping methods at 32 trapping sites across 4 regions, we trapped 3,918 adult female mosquitoes belonging to 43 species; Table S1). For more information about the adult trapping methodology at these water bodies, see Electronic Appendix S1 and a detailed description in Gorsich et al (2019). Our eDNA approach assessed the larval community in a single discrete water body at a single point in time whereas the adult trapping method assessed the adult community around a given water body during multiple trapping nights.…”

Morphology and mini‐barcodes: The inclusion of larval sampling and NGS‐based barcoding improves robustness of ecological analyses of mosquito communities

“…These traps are relatively easy to set up and are efficient in collecting many species which use carbon dioxide as host cues. However, as host‐seeking behaviours differ across mosquito species, the sole use of these traps may skew diversity and abundance estimation (Burkett et al., 2001; Cansado‐Utrilla et al., 2020; Gorsich et al., 2019). CO 2 ‐baited traps also preferentially attract female mosquitoes as only females require blood meals for oogenesis.…”