August Thorn - Ennomos quercinaria

Description

Wingspan 42 to 50 mm. One of several similar 'Thorns', the adults of this species can be distinguished by the shape of the cross-lines on the forewing. The inner line is distinctly curved, and the outer line has a 'kink' where it meets the leading edge.

Similar Species

It is very similar to the September Thorn. Perhaps the easiest way to distinguish them is that the September Thorn has all-yellow legs whilst the August Thorn has 'knee socks' where the lower part of the legs is whitish.

The August Thorn also has the line nearest the base of the wing acutely angled at the costa whilst this is almost straight in the September Thorn.

Identification difficulty
Habitat

It inhabits woodland and suburban habitats.

When to see it

Flying in August and September, the species is often attracted to light.

Life History

The foodplants are trees such as Oak (Quercus) and Beech (Fagus).

UK Status

It can be found locally throughout most of Britain. In a recent survey to determine the status of all macro moths in Britain this species was classified as local.

VC55 Status

Fairly frequent but not common in Leicestershire and Rutland. L&R Moth Group status = B (scarce resident or restricted distribution or regular migrant).

Reference
70.233 BF1912

Leicestershire & Rutland Map

MAP KEY:

Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2025+ | 2020-2024 | pre-2020

UK Map

Species profile

Common names
August Thorn
Species group:
insect - moth
Kingdom:
Animalia
Order:
Lepidoptera
Family:
Geometridae
Records on NatureSpot:
12
First record:
17/08/2015 (Russell, Adrian)
Last record:
19/07/2025 (Johnson, Andrew)

Total records by month

% of records within its species group

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