General Remarks:
Large, pale forms of the female can look confusingly like similar forms of female Common Swifts. Separation is easily effected by looking at the diagonal white line on the forewing, which runs to the apex in Common Swift and to the leading edge of the wing, just before the apex, in Orange Swift.

Hertfordshire Notes: First listed for the county by J. F. Stephens from Hertford in his Illustrations of British Entomology : 8, published in 1828, it appears to have been widespread when Foster wrote his 1937 Hertfordshire inventory, although many of the 15 localities that he noted relate to lists made tens of years earlier. Interestingly, this moth is also poorly represented in the county's strictly calcareous grasslands, evidently preferring those of a more mesotrophic nature; this may partly explain the blank area in the north-east of the map where the Chalky Boulder Clay provides a basis for an intensely arable area.

Middlesex Notes: Widespread and common away from the most densely urban area of central London. Adults August and September. Unkempt gardens, including neglected lawns, may possibly be amongst the reasons why this species is evidently able to thrive in the urban zone of London, although the map does show an apparent absence from the south-east (the City and other parts of central London) where there may simply be no areas of suitable habitat to occupy.

Recorded in 35 (85%) of 41 10k Squares.
First Recorded in 1887.
Last Recorded in 2023.