On the search for the Tiree Twist - Steph Cope

The story of the Tiree Twist, a dainty moth with creamy white body and contrastingly brown band across the wings, is one wrapped in mystery…

The Tiree Twist moth (or Periclepsis cinctana) formerly occurred in Kent up to the 1950s, flying as an adult in the Southern English sunshine. The population declined, however, and it is now believed to be extinct in England.

And yet, nearly 600 miles northwards, this tiny beautiful moth popped up on the Island of Tiree in 1984. Until 2007, that is, as it then disappeared for another 12 years. This would not have been the only case of extinction for moths, as over 56 species have been lost in the British Isle’s since 1914 (thankfully, six of these have been re-found or recolonised). Due to the moth’s great rarity, it was, quite rightly, placed in the highest threat category in the Scottish Conservation Strategy.

Come 2019 and to the delight of a specially formed search team of ecologists and passionate volunteers, the species was spotted again on Tiree! Around Balephetrish where the moth was originally discovered in 1984. However the moth was very localised, only occupying tiny fragments of habitat.

As fate would have it, Phil Sterling, a moth enthusiast and Butterfly Conservation’s Building Sites for Butterflies Programme Manager, happened to visit Tiree on a family holiday in May 2019. Along with Tom Prescott, BC’s Senior Conservation Officer for Scotland, and John Bowler, RSPB’s Conservation Officer on the Island, they visited the precise location where 6 individual adults had been spotted earlier in 2019. to search for the moth’s caterpillars which have never been previously found in the wild in the UK. Hopes spiked as they spotted some unfamiliar looking caterpillars in tight spinnings on Bird’s-foot Trefoil. However, the team had to wait a somewhat agonizing few weeks for the caterpillars to grow, pupate and emerge as adults in order to confirm their species.

Disappointingly, the adults that emerged were Cnephasia conspersana. Not to be pessimistic, the team were still pleased with their findings, as this was also the first record of this species for the Island. Thus, the hunt for the Tiree Twist continues.

If we are to conserve one of the UK’s rarest moths, we need to find out more about the moth’s life-cycle, habitat requirements and caterpillar food plant preferences.  We can only do this by encouraging people to get out there and look for either the adults or particularly the caterpillars.

That’s where you come in!

If, like Phil, you happen to be visiting Tiree, we urge you to take action and help us in the hunt for the Tiree Twist to help us get to the bottom of their mysterious distribution and life-cycle. 

The caterpillars of this species have never been found in the wild, but our experts believe they probably live in a silken tube or tent and feed on Bird’s-foot Trefoil, Kidney Vetch, and other low-growing plants. It is also thought that the species may also be associated with the island’s Hornblende-rich rocks which these potential foodplants favour on Tiree. The caterpillars will probably be found from around September to the following June meanwhile adult moths would be flying from mid-June to Mid-July. So get out there Tiree Treasure Hunters!

If you’d like to get involved in this please contact Tom Prescott at Butterfly Conservation Scotland to run through some do’s and don’ts of moth hunting at @email Tel: 01540 661469 Mob: 07979 785665.

Alternatively, anyone across Britain can help by raising awareness of this rare species by purchasing a Tiree Twist window sticker. These are available from Friends of Tiree, please get in touch with Hayley at @email to get these for £3.

Moths Matter!

Moths Matter
Butterfly Conservation works tirelessly to ensure the diversity and abundance of all moths thrives. Unfortunately, there have been worrying declines in the past 40 years with more species going extinct due to land management, light pollution, and climate change. Please download the guide available to celebrate #MothsMatters 2022.

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