About 5–7 mm long.
Fine-art photographic collection
Gymnosoma rotundatum
A round orange fly that tracks shieldbugs by their own chemical messages and turns them into living nurseries.
About this species
Ladybird Fly
Gymnosoma rotundatum(Linnaeus, 1758)
Information reviewed15 July 2026
Gymnosoma rotundatum is a small tachinid fly that parasitises shieldbugs. Females locate hosts and attach eggs to the outside of the bug; the fly larva then enters and develops at the host’s expense.
Taxonomy
Animalia · Arthropoda · Insecta · Diptera · Tachinidae · Gymnosoma
Accepted taxon. · checked 2026-07-15
Europe and temperate western AsiaBroad range and selected reference localities — not a complete occurrence map.
Europe and temperate western Asia
Warm grassland, woodland edge, hedgerows and flower-rich sites containing shieldbugs.
Diurnal; adults visit flowers in summer.
Adults take nectar; larvae are internal parasitoids of shieldbugs.
Solitary.
What makes this species remarkable?
The female can home in on chemical aggregation signals released by shieldbugs — effectively using the host’s own message as a tracking beacon.
An egg is glued to the outside of the living bug; after hatching, the larva penetrates the body and develops internally.
The compact orange abdomen makes the fly resemble a tiny winged ladybird, but its life cycle is that of a specialist parasitoid.