Distribution and Abundance:  Very common.

Primary Habitat:  General occurrence.

Flight Period:  Single brooded in May and June.

Observations:  Very variable in colour with unicolorous forms occurring commonly in both sexes. The moth swarmed at light at dusk on 22 May 1993 on the limestone grassland at Collyweston Quarry; but can also be variable in abundance as shown by the catches at the Fineshade Rothamsted light trap for the eight years to 2000. The annual numbers recorded were as follows:  1993 – 16, 1994 – 3, 1995 – 12, 1996 – 225, 1997 – 250, 1998 – 12, 1999 – 16 and 2000 – 16.

L.O.N.:  Undated. Abundant everywhere.   

First Record:  1842, Clark.