Oak Eggar (Lasiocampa quercus) lives in moorland and heath across Europe and the British Isles. It feeds on lowland grasses leaves.
Fascinating facts about the Oak Eggar
- The oak eggar's wingspan ranges from about 45 mm in males to up to 75 mm in females, the larger sex also being paler. This makes it Britain's largest day-flying moth, easily noticeable when it darts across sunny heathland. Its broad habitat includes scrub, heath, moor, downland, hedges and sea cliffs, giving it many places to be seen.
- In the cooler northern parts of its range the oak eggar requires a full two years to complete its life cycle. Larvae spend the first winter feeding low on plants before pupating and remaining dormant through the second winter, emerging as adults in the following summer. This slower development gave rise to the name northern eggar, now regarded as the subspecies Lasiocampa quercus callunae, which tends to be the larger form.
- When ready to transform, the oak eggar caterpillar spins a silken cocoon on the ground whose exterior is hard, yellowish and unmistakably shaped like an acorn, a feature that inspired its scientific name. The term "egg ar" itself is an obsolete word referring to this acorn-like cocoon. This sturdy, camouflaged casing protects the pupa from predators and environmental stress until the adult emerges.
- When a baculovirus infects an oak egger caterpillar it alters the larva's normal habit of feeding close to the ground, making it climb out of the low scrub where it is usually hidden. This forced exposure leaves the caterpillar easy prey for birds and other predators, which in turn helps the virus spread more rapidly through the population.
- A female oak eggar that has not yet mated can attract many males. These attracted males are typically day-flying insects, while the females themselves tend to be active from dusk onward.
Sources
Every fact above was checked against these pages, and kept only where one of them states it.
At a glance
RangeEurope and the British Isles
HabitatMoorland and heath
DietLowland grasses leaves
About the Oak Eggar
In the dappled light of ancient woodlands, the Oak Eggar moth glides with effortless elegance, its mottled brown wings beating in a slow, hypnotic rhythm as it navigates the intricate tapestry of tree branches and foliage. With a subtle beauty that belies its robust constitution, this master of camouflage weaves through the undergrowth, its caterpillars leaving behind a trail of delicate, silk-wrapped packages that hint at the hidden world of this enigmatic creature. As it moves unseen, the Oak Eggar embodies the quiet, unassuming resilience of the natural world, a testament to the enduring power of life in the most unexpected places.
Hear the Oak Eggar, and 4,400+ more
Real recorded sounds, 11 nature games and a free Daily 5, 1v1 quiz duels, conservation wins and a safe Kids mode. Free on Feravox.
More insects and spiders to discover
