Male. Taken at Shilton, Oxon., on July 13th 2025. (© David Hastings)
(1/200th sec at f/11)

Female. Taken at the Warburg Reserve, Oxon., on June 28th 2009. (© David Hastings)
(1/25th sec at f2.8)

Description

Family: Hepialidae (ABH : 3.005)

Wing span: M: 42 - 58mm; F: 42 - 70mm

The largest British swift, and unmistakable. The male usually has plain chalky-white forewing and hindwing. The female has a yellowish forewing, marked with orange-brown.

It can be found throughout the British Isles, although usually at low altitude in Scotland.

Typical habitats are grassy or weedy places, often where the soil has been disturbed.

The larva over-winters twice and pupates undeground. Adults are on the wing from June to early August.

The larvae feed on the roots of grasses and many other wild and cultivated herbaceous plants.

Both sexes fly at dusk and after dark, and come to light.

Earliest UK sighting: 28th June ; Latest UK sighting: 13th July

Sightings