Differential morphological responses of chironomid larvae to severe heavy metal exposure (Diptera: Chironomidae)

Larval midges (Diptera: Chironomidae) exposed to high concentrations of heavy metals in a stream flowing through an area of defunct lead and zinc mines exhibited differential morphological deformation. Larvae in the subfamily Orthocladiinae had significantly more frequent and severe deformities than larvae in the subfamily Tanypodinae (paired sample t-tests, P < 0.01). The frequency of antennal deformities in the Orthocladiinae was significantly different between sites (P < 0.05, Kruskal-Wallis Median Test) and generally increased with the concentration of heavy metals in the sediment.