General Remarks:
Very much local, but often numerically abundant in woodlands and other places where it occurs. In the years 2022 and 2023 it was found at several new sites, though most of these were not or only poorly studied places, rendering it unclear if the moth was a new arrival there or just overlooked.If the former, this might suggest a slight spread of this species?

Hertfordshire: LOCAL, but usually numerous at sites where it is present.
Old records in Foster's 1937 list number just five - St Albans, Watford, Hitchin, Tring and Berkhamsted, though all relate to the period prior to 1920. In The Moths of Hertfordshire (2008) we noted an affiliation with areas of the county on a Clay-with-Flints geology with 14 map dots, one on the Gault Clay and 13 on Clay-with-Flints. The old records also emanated from areas with a Clay-with-Flints geology and the species appeared to be quite absent from the London Clay-dominated South Herts Plateau and from the Chalky Boulder Clay areas of the north and east, as indeed it was from the Chalk proper. We concluded that a Clay-with-Flints geology was necessary for the moth to persist and within this it may require extensive areas of long-established Bracken in older woodlands. This suggestion was supported by data from Essex, to the east, where Jermyn (1974) shows a complete absence of Clay-with-Flints substrate and according to Goodey (2004) the Map-winged Swift was represented on the county list by just two examples (in the years 1842 and 1860) and was apparently absent at 2004. Similar comparisons could be made with the Drift Geology map of the London Area (Plant, 1994). In Bedfordshire, to our north, at least the five most southerly of their eight records appear to be related to a Clay-with-Flints soil.

In 2023, however, the situation has changed with a good many records related to woodlands with Bracken that are not associated with a Clay-with-Flints geology. Although recording effort since about the year 2000 has increased significantly to cover all corners of the county, the Map-winged Swift has appeared at a number of sites from which it was apparently absent in the past leading to the likely conclusion that it has significantly expanded its range across the county.

Middlesex: EXTINCT
Our single modern report is from Fir & Pond Wood Nature Reserve on the Hertfordshire boundary during 2015, but the moth does not appear to breed there. Otherwise recorded in the vice-county at Greenford in 1950, Bushey in 1974, Stanmore in 1979 and then Old Park Wood, Ruislip in 1984. There are no subsequent records in spite of survey work and this species is currently considered to be extinct in Middlesex.

	Retained Specimen / Photograph will be Required.

Recorded in 20 (49%) of 41 10k Squares. First Recorded in 1888. Last Recorded in 2022. Additional Stats

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