Description: Wingspan 48-72mm. Adult males are reddish brown with two medial cross lines on the forewings. The female has similar markings but the overall colour is greyish brown. May to early August.

Irish Distribution: Widespread and frequently encountered throughout all counties including Rathlin Island.

Ecology: A species associated with heaths, bogs and coastal dunes. The day-flying males are more elusive than the Northern Eggar and are seldom encountered by day. This may be because they usually fly in late afternoon. Their fast rapid flight makes them difficult to identify with certainty in the field without capture since they often share similar habitat with the Northern Eggar. The larvae feed on bilberry and bramble and are often found exposed on open ground especially in coastal habitats prior to hibernation in the autumn. The larvae emerge in early spring and bask in sunshine for a short period before pupation. They are often parasitised and predated on by moorland birds.

Distribution Map from NBN: Macrothylacia rubi at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Macrothylacia rubi at iNaturalist World Species Observations database.