An army of exotic migrant moths has invaded Britain under the cover of darkness, encouraged north by the gentle southerly breezes and balmy evenings of an Indian summer.

 

The unprecedented autumn influx of rare insects includes the rosy underwing, the crimson speckled and the sinister death's head hawkmoth, with another rare migrant moth, the Clifden nonpareil, establishing itself as the country's newest resident breeding species.

 

The largest and most majestic of the underwing moths, the Clifden nonpareil displays a vivid flash of blue on its underwing to ward off predators. Extinct as a breeding species in Britain since the 1960s, lepidopterists believe that individuals from continental Europe have once again established breeding colonies because it has been found in Dorset, Hampshire and Sussex.

 

While many immigrant insects get a bad press, including moths such as the horse-chestnut leaf miner which cause aesthetic damage to chestnut trees, moth experts say the current influx is entirely benign, and the newcomers pose no threat to any native species.

 

This year is likely to be the best ever for the delicate vestal moth, which has been caught in moth traps as far north as Scotland in numbers not seen since the 1940s. There have only ever been 10 records of the rosy underwing before 2013, when at least three have been recorded, including two at one location, which could again suggest a new colony establishing itself.