Rare moth flutters back from brink

Rare moth flutters back from brink

Rare moth re-discovered on Isle of Wight - the last remaining stronghold in the UK

During National Moth Week (22nd – 30th July), conservationists from Hampshire & Isle of Wight Wildlife Trust (HIWWT) are pleased to announce that the Reddish buff Moth (Acosmetia caliginosa), a rare moth species which is only found on one site in the UK, has been recorded for the first time in four years.

Two Reddish buff moths were found during the Trust’s annual moth survey programme at a sanctuary site on the Isle of Wight. The last adult moth was found in 2019, and the new finds help raise hopes for the future of this endangered moth.

Reddish Buff Moth on plant stem

© Tracy Dove

Jamie Marsh, Director of Nature Recovery, Wilder Wight & Wilder Seas, for Hampshire & Isle of Wight Wildlife Trust said: “This is a significant and reassuring find as we were concerned about the status of this endangered species. Covid massively impacted our survey efforts in 2020 and 2021, when only one single larvae was found, so to discover that the Reddish buff moth is still persisting is very exciting.

“It is a difficult moth to survey for and requires a lot of time and effort. It doesn’t readily come to light traps and can easily hide away, so it is very fulfilling to discover two individuals. We were getting nervous that the species had been lost so to find it this year, and have it verified by the UK’s leading expert, is a big relief.”

Three people stood around moth trap. Surrounded by green vegetation.

© Kate Garnham 

The moths last remaining stronghold, which is within a closed sanctuary site for wildlife, contains an ideal mix of its most favoured habitat along with saw-wort (Serratula tinchoria), the sole larval food plant.

As Jamie explains: “The Reddish buff moth has a particular habitat requirement in order to survive and flourish. Our intensive management of the reserve has increased pockets of suitable habitat and the required microclimate for this species to thrive. This is composed of a mosaic of open heathy shrub and short grassland, with important blocks of scrub to provide shelter and create the desired microclimate.”

The Reddish buff moth is in the family Noctuidae, which are also referred as Owlet Moths, and its flight period is from April through to July. Its copper-coloured forewings and pale red hindwings helps it to blend in with its surroundings and attract potential mates. The Reddish Buff is a medium-sized moth with a typical wingspan of up to 15mm and weighs just 23mg.

Jamie concludes: “The Reddish buff moth epitomises the challenges many of our rare species face. Restricted to a single site with specific habitat requirements and a single food plant, it seems to have everything against it, yet it is still persevering, thanks to the hard work of the team, a dedicated group of volunteers and site partners Isle of Wight AONB, Butterfly Conservation, Amazon World and Wildheart Animal Sanctuary.”

The Trust’s remaining focus for the site is to continue to restore and improve the habitat for the moth and other species.

Reddish Buff Moth on egg carton

© Ian Outlaw