Dark and light crimson underwing
Beautiful but rather rare – the dark crimson underwing ‘catocala sponsa’ and light crimson underwing ‘catocala promissa’ frequent more open parts of old oak woodlands, preferring large, mature oaks.
The dark crimson is mainly restricted to the New Forest, whilst the light crimson also occurs in Wiltshire with occasional records in Dorset.
They are attracted to sap runs on damaged trees, usually oaks, mostly at dusk, but sometimes by day (see goat moth). Just before dusk they may also fly high around oak tree canopies, or accumulate on trunks and branches.
Eggs overwinter. After feeding on oak buds and catkins in April, the well camouflaged larvae progress to oak leaves until early June.
Look out for these moths from late June to August. Dark crimson seldom appear before late July and if you find one; don’t forget to photograph it. They can be found at rest on tree trunks, but are extremely well camouflaged.
Conservation status: both Red list.
Photos: Russell Wynn