General Comments:
Widespread but local in Hertfordshire and the northern edge (only) of Middlesex.
The absence of this birch-feeding species from most of Middlesex is surprising. Factors affecting distribution are evidently more involved than simple foodplant availability and call for investigation.

Hertfordshire Notes:
The absence of this species from the north of the county appears to be genuine and perhaps reflects the calcareous soils that render the area generally unsuitable for birch trees. Interestingly, however, this theory is less well-supported by the distribution of Pebble Hook-tip, also a birch feeder and whose alternative foodplant of alder is rare in the north-west. The 1997 Bedfordshire moth book shows records in that county along our north-west border; perhaps we have more work to do here! In the southern two-thirds of the county, on the other hand, the moth is likely to turn up in light traps wherever birch trees can be found, both in woodlands and in more suburban settings such as parks and gardens. Adults and larvae can be shaken from birch trees in the appropriate season.

Middlesex Notes:
EXTREMELY LOCAL. Apart from a singleton in Fulham during 1980, it is apparently restricted to the North London Woodlands band on the border with Hertfordshire. My statement in Larger Moths of the London Area (1993) that it is likely to be present wherever there are birch trees was clearly premature (it was largely based on the occurrence of the Fulham record, which now shows as being far from typical).

Recorded in 22 (54%) of 41 10k Squares.
First Recorded in 1887.
Last Recorded in 2022.