A light brown colour form of the Large Yellow Underwing moth feeds on a buddleia bush in late September.
The Large Yellow Underwing (Noctua pronuba) is a moth, the type species for the family Noctuidae. It is an abundant species throughout Europe, one of the most common and most familiar moths of the region. In some years the species is highly migratory with large numbers appearing suddenly in marginal parts of the range.
This is a quite large and heavy moth with a wingspan of 50–60 mm. The forewings are quite variable from light brown to almost black. The darker individuals often have a pale streak along the costa. The hindwings are bright orange-yellow with a black sub-terminal band. As with other Noctua species (and numerous other insects), this contrast of drab-at-rest and bright-in-flight is used to confuse potential predators.
This species flies at night from July to September and is attracted to light, sometimes in huge numbers. It will also visit flowers such as Buddleia, ragwort and Red Valerian.
Description taken from Wikipedia: http://en.wikipedia.org/wiki/Noctua_pronuba