Assessing the performance of bloodfed mosquito collection strategies in Australia

Bloodfed mosquitoes provide direct evidence of host use, a critical factor for understanding and managing mosquito-borne diseases, yet they are difficult to collect. This study assessed 6 bloodfed mosquito collection methods: direct aspiration, 2 commercially available surveillance traps, and 3 types of artificial resting shelters (ARS) at commercial piggeries and in nearby wetlands within Australia. Methods were evaluated for collection success (ability to capture bloodfed mosquitoes in field conditions) and efficiency (bloodfed mosquitoes collected per minute of effort), while also evaluating the influence of temperature, precipitation, and water index on trapping outcomes using a generalized linear mixed model. Of the 2,530 bloodfed mosquitoes collected, aspiration achieved the highest overall success, largely due to 2 exceptionally productive sites. Two ARS (large bins and felt bags), however, performed more consistently across locations and were particularly efficient in locations with fewer bloodfed mosquitoes. Collection method strongly influenced species composition: aspiration and ground-level ARS collected primarily Culex annulirostris Skuse (Diptera: Culicidae), whereas felt-bag ARS suspended from trees captured proportionally more Anopheles annulipes Walker (Diptera: Culicidae). Aspiration and ARS were most effective near dense, humid ground vegetation: habitats that concentrate resting mosquitoes. These findings suggest a 2-step approach to optimize collection outcomes. First, identify natural resting locations, then match the collection to local abundance and target species: aspiration for ground vegetation with abundant Culex species, ARS (especially felt bags) for low-abundance or arboreal-resting species. This framework supports more targeted and efficient surveillance of mosquito feeding patterns.