Photo © Mike Wall

August Thorn

Ennomos quercinaria

Checklist Number
70.233 [B&F: 1912]

Verification
Record will require further evidence, at least a good photograph, unless CMR is aware recorder has confidence in identification

Classification

Family:Geometridae
Subfamily:Ennominae
Genus:Ennomos
Species:quercinaria
Authority:(Hufnagel, 1767)

Local in woodland, parks, hedgerows, scrubby downland and gardens throughout England and Wales, a species of conservation concern under the UK Biodiversity Action Plan. Widely distributed, but perhaps decreasing, in Hampshire and the Isle of Wight. Wingspan 42-50 mm. Probably easier to confuse with Dusky Thorn E. fuscantaria than September Thorn E. erosaria, which see, since a good proportion of August Thorn show dark shading between outer cross-line and outer edge of wing, the stated diagnostic feature for Dusky Thorn; the three species all show subtle differences in the way the outer cross-line meets the costa. Larva feeds on Pedunculate and Sessile Oak, over-wintering as an egg.

The abundance in each month is indicated as follows:

No records
Very occasional
Irregular
Uncommon
Off-peak, but not unusual
Off-peak, but not unusual
Main flight time
J F M A M J J A S O N D
Adult
Larval

Records by week (adult)

Records by week (larval)