Use of Chironomidae (Diptera) Surface-Floating Pupal Exuviae as a Rapid Bioassessment Protocol for Water Bodies

Abstract

Rapid bioassessment protocols using benthic macroinvertebrate assemblages have been successfully used to assess human impacts on water quality. Unfortunately, traditional benthic larval sampling methods, such as the dip-net, can be time-consuming and expensive. An alternative protocol involves collection of Chironomidae surface-floating pupal exuviae (SFPE). Chironomidae is a species-rich family of flies (Diptera) whose immature stages typically occur in aquatic habitats. Adult chironomids emerge from the water, leaving their pupal skins, or exuviae, floating on the water's surface. Exuviae often accumulate along banks or behind obstructions by action of the wind or water current, where they can be collected to assess chironomid diversity and richness. Chironomids can be used as important biological indicators, since some species are more tolerant to pollution than others. Therefore, the relative abundance and species composition of collected SFPE reflect changes in water quality. Here, methods associated with field collection, laboratory processing, slide mounting, and identification of chironomid SFPE are described in detail. Advantages of the SFPE method include minimal disturbance at a sampling area, efficient and economical sample collection and laboratory processing, ease of identification, applicability in nearly all aquatic environments, and a potentially more sensitive measure of ecosystem stress. Limitations include the inability to determine larval microhabitat use and inability to identify pupal exuviae to species if they have not been associated with adult males. Video LinkThe video component of this article can be found at

Conochironomus (Diptera: Chironomidae) in Asia: new and redescribed species and vouchering issues

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DNA barcodes and morphology reveal unrecognized species in Chironomidae (Diptera)

“…Immature life stages are important in biodiversity assessments of chironomids and biological monitoring (Anderson et al 2013;Ekrem et al 2010;Ferrington et al 1991;Kranzfelder et al 2015;Raunio et al 2007). In particular chironomid pupal exuviae might provide important characters to help resolve taxonomic issues for cryptic species complex.…”

Establishing laboratory cultures and performing ecological and evolutionary experiments with the emerging model species Chironomus riparius

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