Yellow-barred Brindle Geometridae

Acasis viretata (Hubner, 1799)

Description: Wingspan 25-29mm. Adults are olive green when freshly emerged. The dark cross-lines are wavy and dotted with black. The ground colour tends to fade fairly quickly after emergence giving a totally different appearance to the moth and may result in misidentification. Most adults captured at light tend to be light brown, often with little sign of the olive green colour.

Key Identification Features:

Sets:  male upperside

Flight Period: early April to the beginning of September although more frequent in late spring.

Status: Widely distributed (but never commonly encountered) in southern counties particularly Down and Fermanagh. It was previously considered extremely scarce, however targeted fieldwork in some of the well-known sites has recently produced a number of records. It may exist more widely in some other mature woodland sites if looked for at the appropriate time.

Ecology: A spring species normally associated with well-established mature woodland where Holly Ilex aquifolium is common. Adults are attracted to light in very small numbers. It often rests during the day on the trunks of trees. The larvae can be found in June and July on Holly, Ivy Hedera helix and Wild Privet Ligustrum vulgare. It overwinters as a pupa.

World Distribution: Throughout Europe to western India and Japan.

Bradley & Fletcher number: 1883 Agassiz number: 70.200

Additional information:

UK Moths account


 Thompson, R. S. & Nelson, B., 2003 (Oct 2). [In] The Butterflies and Moths of Northern Ireland