Moth and Butterfly Migration

©Adam Gor

It's not just birds that are on the move, butterflies and moths are on the wing in early autumn. Here are a few species to look out for at the moment.

At this time of year many people can get preoccupied with birds when talking about the autumn migration season. However, there’s more moving around than just birds!

This past week has brought a new moth species to the island, the box tree moth. Both light and dark forms have been found in traps recently. The moth has been increasingly sighted in the UK since 2007, although it is a native to Asia. This species can be a serious pest of box plants, defoliating them and disfiguring the trees. It was highly likely they would be spotted here soon, but highlights the issues with the international trade in plants that likely introduced the moths or their caterpillars to Europe.

Another moth to look out for, decidedly more showy, is the Clifden nonpareil or blue underwing. They went extinct in the UK in the 60s but have recently re-established breeding colonies in southern England and are spreading northwards. The caterpillars feed on aspen so protecting aspen trees and woodland is important in areas it is now breeding. It does not breed in Alderney but lots have been found, especially in the AWT moth traps for the past three weeks running.

The race is on to spot the Southern small white butterfly. A species usually found in south eastern Europe but one which is again spreading rapidly north. It’s hard to tell apart from our regular small white but is expected to cross the channel soon – making the Channel Islands very likely for a first record.

Finally, a recent find of the Death’s head hawk moth by an Alderney resident provided a special sighting. These are another moth species that are associated with the south, especially the Mediterranean. Their caterpillars feed on potato plants and nightshades and adult moths will make a squeaking sound when surprised.

Don’t forget the AWT runs a moth trap open to all every Saturday 9am at Essex Farm.