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Toe-winged beetles

Guide to New Zealand's freshwater invertebrates

Toe-winged beetles ( Ptilodactylidae : Ptilodactylidae )

Larva with flat upper surface of the 9th abdominal segment
9th abdominal segment

Diagnostic features

Ptilodactylids are beetles with long, mealworm-like larvae that live in streams, but the adults are terrestrial. The larvae have a similar body form to the elmids, but ptilodactylids are usually larger and more orange-brown than elmids. The last (9th) abdominal segment has a flat upper surface, which is not the case in the elmids.

Typical habitats

Ptilodactylids can be common in some slow flowing bush covered streams.

Feeding

Ptilodactylid larvae are likely to be “collector-gatherers” feeding on a range of fine organic matter trapped amongst, or growing on the streambed.

Indicator value

Ptilodactylids are usually found in streams with moderate to good water quality. They have tolerance values of 8 (hard bottom sites) and 7.1 (soft bottom sites).