Look out for: moths in November

December moth

Butterflies are tucked away for winter or have emigrated to warmer climes, but for some moths the year is just getting started.

The Red-green Carpet is one of the prettiest moths flying at this time of year, with green wings flecked with muted red streaks or patches. Individual moths vary within this basic pattern, from striking deep, bottle green specimens through to greyish, mossy coloured ones. On some the reddish hues are prominent, on others scarcely discernible. The sexes vary too, with females said to be a darker, stronger green in general. 

Red-green carpet mothThe caterpillars of Red-green Carpet feed on oak and other deciduous trees, so the moths are usually encountered in woodland, along hedgerows and in gardens. It is a nocturnal species that comes readily to moth-traps, but you don’t need to own a trap to see this autumn beauty; Red-green Carpets are regularly attracted to the low-energy bulb in our porch light and they can also be found by searching ivy blossom at night.

There’s more of interest about Red-green Carpet moths than their colours though. After their autumn flight period, they hibernate through the winter and then emerge to fly again in the spring. However, it is only the females that hibernate; the males do not survive the winter. Mating occurs in the autumn and the females then lay eggs during their second, springtime flight period. Thus, all Red-green Carpets seen in spring each year are females.

It is also a species that has done very well over recent decades, bucking the general trend of decline among UK moths and butterflies. Red-green Carpet has increased greatly in abundance at sites monitored nightly as part of the Rothamsted Insect Survey, with a 739% rise in its national population trend over 40 years (1968-2007). The moth has also become significantly more widespread over the same period, especially in the eastern half of England.

Other moths that have their main, or only, annual flight period at this time of year include the distinctive Black Rustic, with its velvet-black forewings contrasting sharply with white hindwings, the Feathered Thorn, which resembles a fallen autumn leaf, and the December Moth, with its densely-furred body wrapped up against the cold night air. 

Light Brown Apple mothThe most common moth in my garden moth-trap at this time of year, however, is a small, brown and tan micro-moth and one that isn’t even originally native to the UK. Epiphyas postvittana, a.k.a. the Light Brown Apple Moth, was first found to be breeding in Britain in Cornwall in 1936, having been, it is assumed, accidentally imported from its native Australia. For the first few decades the distribution of the moth spread only slowly, but since the 1980s it has raced away, reaching Scotland in 2001, the Isle of Man in 2002 and Northern Ireland by 2003. 

It has a very wide diet, with caterpillars capable of feeding on trees, shrubs and herbaceous plants and on dead vegetation as well as many parts of growing plants. Perhaps thanks to this diverse diet and adaptation to the climate of its ancestral homeland, the Light Brown Apple Moth pays little heed to the changing UK seasons. It continues its breeding cycle throughout the year, with no pause for hibernation, and has been recorded on the wing in every month. This is reflected in my own garden, where Light Brown Apple Moth is the most frequently caught species in my moth-trap (i.e. it is present in the trap on more occasions through the year than any other species) and also the third most abundant species overall. 
Many people shy away from learning to identify micro-moths, but the Light Brown Apple Moth, especially the distinctive two-tone male, is one to look out for at this time of year. 

Richard Fox

Head Of Recording

Follow me on Twitter: @RichardFoxBC

Images: Red-green Carpet Moth by Dave Green and Light Brown Apple Moth by Mark Parsons.