Chironomid midge (Polypedilum)

Taxonomic group

Chironomidae: Polypedilum

Diagnostic features

Polypedilum is a commonly occurring member of the Chironomini subfamily of chironomid midges. Like other chironomids the general body form is worm-like, but with a distinct head, and with paired prolegs under the head and at the end of the abdomen. Polypedilum may be red when live or pale when preserved. The eyes are split into two barely-separated parts, one above the other (often in a figure “8” arrangement).

[Polypedilum] larvae. Image: Stephen Moore Image — Polypedilum larvae. Image: Stephen Moore

[Polypedilum] larva in plant matter. Image: Stephen Moore Image — Polypedilum larva in plant matter. Image: Stephen Moore

Typical habitats

Polypedilum larvae are found in hard and soft bottom, bush covered and farmland streams. They often burrow into soft plant matter.

Feeding

They are collector-gatherers feeding on fine organic matter including streambed algae.

Indicator value

Hard bottom: 3
Soft bottom: 8.0

The tolerance values (ranging from 0 to 10) give an indication of which are the sensitive taxa (values of 8 or more) and which are the tolerant taxa (values of 3 or less). For more information see: Indicator species

Polypedilum larvae are found in streams of widely varying water quality. They are therefore not likely to be good indicators of water quality. They have wide ranging tolerance values of 3 (hard bottom sites) and 8.0 (soft bottom sites).