Moths Aren’t Drab


Lead-coloured Drab (Orthosia populeti)


The night of 27th-28th March 2019 proved to be the best night of the year, in terms of quantity, for moth trapping at UEA to date, producing 135 moths of twelve species. The catch was dominated by quakers with 57 Small (Orthosia cruda), 38 Common (O. cerasi) and four Twin-spotted Quaker (Anorthoa munda), with two Brindled Beauty (Lycia hirtaria)and three Oak Beauty (Biston strataria) forming part of the catch. Nine Clouded Drab (O. incerta) were the highest total for this species this year so far, however there was an interloper among them… The highlight of the night’s catch was a female Lead-coloured Drab (O. populeti).

Lead-coloured Drab, UEA, 28 March 2019 (Max Hellicar)

 
Description and Identification

The Lead-coloured Drab has two main confusion species in the UK. The most similar of which is the Clouded Drab, which it can be very difficult to distinguish from. The most easily distinguishable features are that Lead-coloured Drab have a round tip to their forewing, which is more pointed in Clouded, and Lead-coloured have a smaller size in general (granted, this is most useful when a Clouded Drab is present for comparison) however there is some overlap in size, with the forewing length of Lead-coloured being 15-17 mm compared to 16-20 mm in Clouded Drab (Townsend & Waring, 2007).

A key difference in male Lead-coloured is that they have visibly feathered antennae, whereas Clouded Drab have finer antennae in both sexes, however female Lead-coloured also have fine antennae, so where confusion arises in areas where both species are present, there is only a 25% chance of this feature being useful! Forewing tip shape and size are the best ways to distinguish female Lead-coloured, as mentioned above, and forewing markings can also be useful, with Lead-coloured often exhibiting a series of small, dark wedges along the sub-terminal line.

Comparison between Lead-coloured Drab (background) and Clouded Drab (foreground), Norfolk, 22 March 2019 (Max Hellicar)

A very instructive and useful comparison can be found here: http://douglasboyes.co.uk/files/Lead-coloured%20Drab.pdf. The other confusion species is Common Quaker due to their similar size, shape and, as a rather plain species, their lack of prominent features, however these are easily identified by their more sandy brown consistent colouration.

Lead-coloured Drab frequent broadleaf woodland and their foodplants are poplar trees (Populus spp.), particularly Aspen (P. tremula). They have one generation which are on the wing from March to April (Wheeler, 2019).


Taxonomy

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Noctuidae
Genus: Orthosia
Species: O. populeti


Distribution and Status

Nationally it is a locally distributed species however it is distributed across much of the UK, albeit sparsely. In Norfolk the species was first recorded in 1873 and has been recorded in 75% of 10 km squares across the county (Wheeler, 2019). A map of species records from the county can be viewed here: www.norfolkmoths.co.uk/?bf=21850. This individual is the first I have recorded at UEA and only the second I have ever seen, after twitching one which had been caught in the Brecks the previous week, and kindly brought back to Norwich overnight for others to enjoy before being released at the site it was caught the following day – with thanks to all those in the Norwich Moths WhatsApp group for sharing their best moths. It’s always satisfying to see a new species of moth, but it’s always even more satisfying to catch and identify one yourself!

Lead-coloured Drab, Norfolk, 22 March 2019 (Max Hellicar)


References and Sources of Information

Kimber, I. (2019). Lead-coloured Drab. Retrieved April 01, 2019, from UK Moths: www.ukmoths.org.uk/species/orthosia-populeti

Townsend, M., & Waring, P. (2007). Concise Guide to the Moths of Great Brtain and Ireland. London: Bloomsbury Publishing Plc.

Wheeler, J. (2019). Lead-coloured Drab. Retrieved April 01, 2019, from Norfolk Moths: www.norfolkmoths.co.uk/?bf=21850

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