They are often tiny, frequently brown and always challenging to identify but an average of one new species of pyralid moth each year is turning up in Britain, according to experts.



Almost 30 new species of this large family of “micro-moths” have been recorded over the last 30 years – either flying in themselves or being transported via the horticultural trade.

While the abundance of moths is in decline, more than 125 new species of moth have been spotted in Britain this century alone, with 27 species establishing themselves as breeding species.

People are being urged to spot and help document these new arrivals as part of this year’s Moth Night, an annual three-night event to record and celebrate moths, organised by Butterfly Conservation, the Centre for Ecology & Hydrology and wildlife publisher Atropos.

“Just because something is called a micro-moth, don’t assume it’s tiny and brown and dull and impossible to identify because some of these aren’t,” said Richard Fox of Butterfly Conservation. “Moths in general are a fantastic, interesting group of wildlife that’s still relatively diverse – there are hundreds of species in your back garden. Anyone who is interested in wildlife will find that exciting and inspiring.”

Musotima nitidalis caterpillar. This species arrived from Australia and New Zealand. Photograph: Mark Parsons/Butterfly Conservation

Newly arrived micro-moths include Musotima nitidalis, originally from Australia and New Zealand, which reached Britain in 2009 via the horticultural trade. The moth is now found in several locations in southern England, where its caterpillars feed on ferns such as bracken.



Many of the recent pyralid colonists have arrived naturally, probably assisted by climate change, including the beautifully coloured Evergestis limbata, which has settled along the south coast of England.

According to Fox, most of the new arrivals are entirely benign although one, the box tree moth, will be unpopular with gardeners for its caterpillars’ habit of devouring the leaves of box hedges.

Easy to see native pyralids include the day-flying mint moth, which can be found among garden herbs and the small magpie – a surprisingly large black and white moth. Common migrants include the rush veneer and rusty-dot pearl.

The brown China-mark. Photograph: Patrick Clement/Butterfly Conservation

The caterpillars of another group of pyralid moth, the china-marks, live in an air-filled bubble of spun leaves, sometimes below the surface of ponds or at the edge of streams.

As well as apps and online guides, there is a new guidebook on pyralid moths to help spotters. Mark Tunmore of publisher Atropos said: “New species are being added to the British list with regularity and we want to make sure that people are well equipped to identify these. We expect Moth Night 2018 to add to our knowledge of this group of moths.”