Species Account

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Summary Data

Season (Adult / Immature):

National Status: Common

Local Status: Scarce and thinly distributed or restricted resident.

Local Record: Grade 2   See here for explanation

Flight time: Two generations, May-Jul and Sep-Oct.

Forewing: 14-18mm.

Foodplant: Common Nettle and Hop.

IMPORTANT - Please note that the maps and accounts are provisional, subject to change and further update.  The whole dataset still needs to go through the final verification process and it is likely that a very small number of records will not satisfy the present requirements and there are other records that have not been formally submitted.  The information is for guidance only.

Record breakdown:

Year first recorded193219861932
Year last recorded201120112011
Number of records62456680
Number of individuals69557752
Unique positions977104
Unique locations82890
Adult records59255647
Immature records000

For the region, we have a total of 680 records from 90 sites. Earliest record on file is in 1932.


2449 Dark Spectacle 02
© Debra Saunders
2449 Dark Spectacle 01
© Tom Morris

Species Account

Similar species: 2450 Abrostola tripartita (Spectacle).

For further information refer UK Moths.

Davey, P., 2009: A thinly spread species in England and Wales, local in Scotland, the larva feeding on nettle (Urtica dioica) and hop (Humulus lupulus). In Dorset, the moth until fairly recently was rare and at low density in river valleys where hop festoons hedgerows, notably on the Stour, the Moors River, and the Piddle, but has increased quite dramatically of late. Originally there was little evidence to support a resident status for the species, but currently, the moth seems to be regularly recorded from a few sites, notably those close to river valleys. This increasing trend seems mostly due to immigration, with in excess of fifty moths trapped in 2001 and 2003 appearing amidst notable immigrations from mainland Europe. The national norm is for a single-brood in June and July, but the Dorset records indicate a double brood pattern, with the peak of the mid-summer brood one-third higher on average, than that of the early autumn peak. Coupled with this are the suspected immigrant peaks in late May, late July and early October, reflecting a trivoltine cycle abroad.

Given the capacity of this species to migrate, it is worth mentioning that two similar species occur abroad, so it may be worth checking dark 'Spectacles' examples, particularly at times of immigration. These two are similar to triplasia, although both are marginally greyer. Also, the inner-most semi-circular black line separating the ochreous region from the remaining dark ground colour of the forewing on triplasia, forms an acute angle (less than thirty degrees) as it approaches the basal edge of the forewing. The other two species have this line forming an angle of forty-five degrees or more with the basal edge of the forewing, so that it appears more of a shallow curve than a full semi-circle along its whole length. The two Continental species are: Abristola asclepiades which has a southern, central and eastern distribution in Europe including Iberia, Germany and southern Scandinavia, and Abristola agnorista which occurs in southern Europe and is essentially a Mediterranean species.

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