Sefton Coast Wildlife

Oak Eggar

Lasiocampa quercus

UK Green ListModerate📍 Ainsdale NNR
Season
Males July–August (daytime). Females nocturnal.
Best time of day
Males: 11am–4pm in sunshine — fast-flying along scrub edges. Females: after dark.
Sefton Coast
Present on dune heath and heathery areas at Ainsdale; males fly conspicuously by day
UK population
Common on heathland and moorland throughout Britain

Tap image to enlarge · Wikimedia Commons

Overview

The Oak Eggar is a large, powerful moth — males fly by day in a rapid, buzzing search for females that are nocturnal and sedentary. Male Oak Eggars can fly for miles following a female's pheromone plume. On the Sefton Coast dune heath they're a characteristic sight in July — large, tawny-brown moths careering past at speed. Despite the name, Oak is not their primary foodplant here — on the coastal heathland they feed mainly on Heather and Bramble.

At a Glance

OrderLepidoptera
FamilyLasiocampidae
HabitatDune heath · Heather moorland · Coastal scrub with Heather
DietAdults: do not feed. Larvae: Heather, Bramble, Hawthorn, Blackthorn, various shrubs.
UK populationCommon on heathland and moorland throughout Britain
Sefton CoastPresent on dune heath and heathery areas at Ainsdale; males fly conspicuously by day
ConservationUK Green List

Where to See It

Dune heath and scrub edges at Ainsdale NNR. Named in Green Sefton accounts of Sefton Coast insects.

Identification

Large, powerful moth. Males: rich tawny-orange-brown, fly by day at speed. Females: larger, paler, nocturnal. Broad, rounded wings. White spot on forewing centre. Fast, direct flight in males.

Viewing & Photography Tips

Walk the heathy areas at Ainsdale in July on a sunny day. Male Oak Eggars fly rapidly past and are hard to follow. Stand still and they may return. Females are found in moth traps at night.

Conservation Status

UK Green List

This species has a favourable conservation status in the UK and remains an important part of Sefton Coast biodiversity.

Frequently Asked Questions

Can an Oak Eggar male smell a female from a mile away?

Yes. Male Oak Eggars have large, comb-like (bipectinate) antennae that can detect female pheromones at extraordinarily low concentrations. Females produce pheromones while sedentary, and males can detect and home in on the source from distances of over a kilometre. This 'assembling' behaviour has been used experimentally — placing a caged female outdoors can attract dozens of wild males.

Related Species

Plan your visit to the Sefton Coast

Marshside RSPB, Formby pinewoods, Ainsdale NNR — practical guides to getting there, what to bring, and the best spots for each season.