Gypsy Moth Lymantria dispar
Wingspan 32-55 mm.
In the early part of the 19th century, this was a common species in the East Anglian and southern fens, but by about 1900 had become extinct as a breeding species.
For a period it was just occasionally recorded as a migrant species with perhaps one or two males per year on average. (The whitish, cumbersome females are much larger than the males, and cannot fly well).
Since 1995 the species has been resident in small numbers in parts of London, where it was subject to an attempted eradication campaign led by Defra but is now resident in small colonies across the south east. The species spreads by the tiny larvae being dispersed by wind.
The larval foodplants are a range of deciduous trees and in continental Europe the species is a common pest.