There are just seven species of Cladius sawfly found in Britain, which, you might think, would make them relatively easy to identify. Sadly, this isn’t the case, especially in their larval forms, as all their caterpillars look very similar, and even the expert I consulted said he was unsure about the larval differences.

However, I seem to have struck it lucky with this particular species as The Sawflies (Symphyta) of Britain and Ireland website says: ‘They can be distinguished from the other elm feeding species, Cladius rufipes, by the presence of a black spot on the front of the face which is absent in rufipes.’ As you can clearly see in the photo above, this larva has that black spot, so meet Cladius ulmi, a sawfly species that feeds on elm, in this case Wych elm (Ulmus glabra).