Discovered earlier this month the creature has now been positively identified by experts as a Trichiosoma vitellina or the red-margined Willow Sawfly, a species that has only been recorded a handful of times in the UK.
Speaking about the discovery Wildlife Trust Head of Communications Erin McDaid said: “These photos have caused quite a stir, there was even a bit of controversy when we described the animal in the photograph as a sawfly caterpillar. Despite us including the scientific name for the species in the post and caterpillar being an increasingly common term used to describe them, it was pointed out to us that they are indeed larvae, not caterpillars and it’s great that people have taken so much interest.
The Idle Valley Nature Reserve is one of the largest protected wildlife areas in the region and covering more than 600 hectares there is plenty of scope for new discoveries, but this species came as a bit of a surprise. As the larvae feeds on willow there is plenty of food for the species at the reserve which is a former area of sand and gravel extraction alongside the River Idle, west of Retford.
Erin added: “We quite often come across new finds for the county or species that have not been recorded for a while but this appears to be quite a rarity, or certainly a species which is under recorded right across the UK.
The Wildlife Trust, a registered charity, cares for over 1300 hectares of nature reserve across Nottinghamshire as well as standing up for wildlife within the planning system, campaigning for stronger wildlife legislation and providing opportunities for people to learn about and discover wildlife close to where they live.