Autumn is typically an exciting time of the year for those interested in moths. Although the great diversity of British moths that are around during the warm summer months is starting to fade, it is the peak time of year for moth immigration.
In good autumns, such as in 2011, huge numbers of moths can arrive in Britain from southern Europe or even North Africa, borne in on warm southerly winds. While some of these are common and familiar migrants such as the Silver Y, Dark Swordgrass and Humming-bird Hawk-moth, other much rarer and more exotic-looking species can arrive, such as the sinister Death’s Head Hawk-moth, the stunning Crimson Speckled, Dewick’s Plusia and Purple Marbled.
The number of exicitng immigrant moths has started to rise in Devon and neighbouring counties in recent weeks with, for example, sightings of the very rare Rosy Underwing in Dorset and Cornwall. This species had only been recorded 10 times ever in Britain prior to this year, but there have already been three sightings in recent weeks (two in south Dorset and one on the Lizard, Cornwall).
I’ve not been lucky enough to see anything so rare (although with moth recording one always lives in hope) but have seen several immigrant Vestal moths in my garden in the last two weeks (one shown below). It’s well worth putting your moth trap out at night between the showers and also keeping your eyes peeled during the day as species such as Convolvulus Hawk-moth and Crimson Speckled are often spotted by day.