Adults are about 6–9 mm long.
Fine-art photographic collection
Helina abdominalis
A scarce woodland fly whose nursery is not a pond or carcass, but the wet heart of an ancient tree.
About this species
Helina abdominalis(Zetterstedt, 1846)
Information reviewed15 July 2026
Helina abdominalis is a scarce European muscid fly associated with veteran trees. Its larvae develop in damp decaying material inside rot holes and hollow trunks.
Taxonomy
Animalia · Arthropoda · Insecta · Diptera · Muscidae · Helina
Accepted taxon. · checked 2026-07-15
Britain, Ireland and parts of continental EuropeBroad range and selected reference localities — not a complete occurrence map.
Britain, Ireland and parts of continental Europe
Ancient woodland, parkland and sites with hollow or decaying veteran trees.
Adults fly in summer around old trees and woodland openings.
Larvae exploit decaying material in tree cavities; adults take liquid foods.
Solitary.
What makes this species remarkable?
One specimen was reared from a pupa found inside a rotten tree stump, and repeated surveys place the larvae in waterlogged rot holes high or low on old trees — a nursery that may take centuries to form.
In Britain it has a provisional Nationally Scarce status, while Irish records are so few and concentrated in old woodland that a single trapped female has been reported as a county first.
The adult may live for only a season, but its life cycle depends on continuity across generations of veteran trees; remove the hollow-tree habitat and the fly disappears long before a replacement cavity develops.
Sources and scientific references
- GBIF — taxon record/search for Helina abdominalis
- Catalogue of Life — taxon search for Helina abdominalis
- Alexander 2002 — larvae in rot holes of old or dead trees and British status
- Wyre Forest Oak Fogging Project — reared pupa and nationally notable status
- Irish Wildlife Manual — first Clare record and old-woodland association