General comments:
Widespread and Local in Hertfordshire, but Absent from all but the northern edge of Middlesex. British examples of this species relate to subspecies galbanus (Tutt); the nominotypical subspecies is absent from Britain.

Hertfordshire Notes:
Grey forms approaching the appearance of the typical subspecies found in Europe occur at relatively low density, perhaps 15 to 20 per cent of the Hertfordshire population during 1995 to 2006, but these are melanic galbanus and not true flavicornis. It is of interest that Ian Lorimer, recorded it as 'Fairly common. All melanic' at Totteridge during 1979. The adult is attracted easily to light if the trap is placed directly under birch trees. At Hares Garden Wood near Tring on 13th February 2004 a trap placed against the trunk of an isolated mature birch caught this species as predicted to an incredulous audience whilst none of the other nearby traps caught any, in spite of there being a smattering of birch trees throughout the woodland. Three unusually late dates recorded in the county are 4th May 2003 at Whippendell Wood (Dave Murray), 16th May 1896 at Bricket Wood (S. H. Spencer) and on 3rd June 2004 at Thunderfield Grove (Mark Cooper). The flight chart excludes historical data.

Middlesex Notes: This moth has a distribution near identical to that of 65.001 Falcaria lacertinaria, also a birch associate, with known sites closely hugging the Hertfordshire border along the whole length (the North London Woodlands), but quite absent from any other part of the county.

Recorded in 20 (49%) of 41 10k Squares.
First Recorded in 1896.
Last Recorded in 2024.