Sloe Pug spreading in Devon?

Sloe Pug Pasiphila chloerata has an interesting history in Britain. Due to its close similarity to the very common Green Pug P. rectangulata, Sloe Pug wasn’t discovered in Britain until 1971, although it had undoubtedly been resident for a long time.

It is now known to be a widespread moth, found as far north as Cumbria, but it does not seem to occur in the far west of England or Wales.  There are very few Devon records and until recently it was thought to be confined to the far eastern edge of the county along the Dorset border.

However, last year confirmed records of Sloe Pug were received from Exmouth and  Orley Common, Ipplepen (near Newton Abbot), greatly extending the known range of the moth westwards.

Most recently, Barry Henwood, the County Moth Recorder, caught a Sloe Pug (shown below) in his garden at Abbotskerswell (only a few miles from Orley Common) on 1st June 2014, raising the possibility that the moth is spreading and may now be more widespread in the county.

Sloe Pug in Devon (June 2014) (Barry Henwood)

Sloe Pug in Devon (June 2014) (Barry Henwood)

It is possible to distinguish Sloe Pug and Green Pug on external characters. The adults of both species are greenish, fading with age. When fresh, Green Pug is brighter green. The first difference to notice is that the postmedian line of the Green Pug has a jagged appearance (with two strong angulations), whereas the same line on Sloe Pug is more of a gentle curve. Sloe Pug has a brick-red ‘belt’ on the base of the abdomen, which Green Pug does not have.

Once you think you have a candidate for Sloe Pug, put it in a jar and look through the glass at the underside of the hindwing. There the post-median line forms an acute angle in Green Pug but an obtuse angle in Sloe Pug.

Further Devon records accompanied by good photos of upper-side and under-side (through glass) would be very welcome.