Etymology

The Helicopsychidae Ross, 1944 is derived from the genus name Helicopsyche von Siebold, 1856 which refers to the helical and dextrally coiled cases made by the larvae

Relationship

The Helicopsychidae form a monophyletic group of derived caddisflies within the superorder Sericostomatoidea

Biodiversity

At present, 203 species have been described within the four genera Helicopsyche von Siebold, 1856, Rakiura McFarlane, 1973, Palaeohelicopsyche Ulmer, 1912 and Electrohelicopsyche Ulmer, 1912.

The largest genus, the Helicopsyche, is divided into the six subgenera Helicopsyche von Siebold, 1856, Cochliopsyche Mülller, 1885, Cochliophylax Schmid, 1993, Feropsyche Johanson, 1998, Galeopsyche Johanson, 1998, Saetotricha, and Petrotrichia Ulmer, 1910.

The two genera Palaeohelicopsyche and Electrohelicopsyche includes only fossil species described from Baltic amber dated to upper Eocene.

The highest diversity is recorded in NE India, New Caledonia, Mexico and the Antilles. These areas include about 50% of the total species number.

Ecology

The larvae of the tropical species appear to prefer permanent, cold, running mountain streams. However, the larva of Helicopsyche borealis (Hagen, 1861) are found also in warm spring water and shore of lakes.

Morphology

The adult Helicopsychidae are recognized from those of other families by having:

• two, three or four-jointed maxillary palps in male and five-jointed maxillary palps in female,
• fore and hind wings without nygma,
• fore wing forks 1,2,3 and 5 present (may be secondary reduced in some species),
• hind wing forks 1,2 and 5 present (may be secondary reduced in some species),
• hind wing with a row of hamuli along the basal half of costa, spur formula 1-2-4; 2-2-4 or 2 2-2,
• reticulated abdominal sternites 2-5 in most species,
• abdominal VIth sternal process present in most species.

The larvae are characteristic in:

• building dextrally coiled larval cases,
• having short antennae situated about midway between the eye and anterior head margin,
• anterior margin of pronotum with megasetae in row (not developed in some species),
• weakly sclerotized metanotum,
• comb-shaped anal claws.