General comments
Extremely local resident.

In Hertfordshire, populations are focussed around the Lea and Stort Valleys in the east (Amwell, Rye Meads and Sawbridgeworth Marsh) and the Wilstone Reservoir area in the west. There are also records from the Colne Valley at Maple Cross in 1996. There is strong evidence to suggest that the moth is a recent colonist in Hertfordshire. Bell (1955) comments that 'A. L. Goodson attracted to his Tring and Ashridge M.V. lamps what was evidently part of a migration, 30 moths attending over a couple of nights in August [1953], mostly at Tring. A single specimen came to my own light on the 11th of that month'. These records are not mapped as the exact locations are unclear. Though Bell does not say so, this is the earliest Hertfordshire record; there are no more until 1977 when it was discovered in Sawbridgeworth Marsh (Fielding et al, 1985). It may or may not be a coincidence that this resident population was discovered the year following one of the longest and hottest summers on record at that date; vagrant moths from the east coast could easily have found the Stort Valley and elsewhere to their liking.The surprisingly wide spread of confirmed records across Middlesex is surprising and calls for investigation.

Recorded in 14 (34%) of 41 10k Squares.
First Recorded in 1977.
Last Recorded in 2023.