Toe-winged beetles (Ptilodactylidae)

Taxonomic group

Family: Ptilodactylidae

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.

Toe-winged beetle (Ptilodactylidae) larva with flat upper surface of the 9th abdominal segment. Image: Stephen Moore Image — Toe-winged beetle (Ptilodactylidae) larva with flat upper surface of the 9th abdominal segment. Image: Stephen Moore

Toe-winged beetle (Ptilodactylidae) larva 9th abdominal segment. Image: Stephen Moore Image — Toe-winged beetle (Ptilodactylidae) larva 9th abdominal segment. Image: Stephen Moore

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

Hard bottom: 8
Soft bottom: 7.1

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

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).