Name that caterpillar

[Ian Pratt]

Just a couple of caterpillars for ID please. One is a knot grass moth I think. Any ideas regarding the other one?

[Mark Colvin]

Hi Ian,

The first one is the Knot Grass (Acronicta rumicis).

The second appears to be a sawfly larva. Although similar to lepidopteran larvae, which have three pairs of thoracic legs, five pairs or less of abdominal prolegs and a pair of anal prolegs at the rear, sawfly larvae have six or seven pairs of abdominal prolegs (as clearly shown in the picture below) in addition to the thoracic legs and anal prolegs. The exception to this are the sawfly species whose larvae live inside the leaves, twigs and timber of trees and plants where evolution has reduced the function of the legs to a point where they are virtually absent in these species.

I hope this helps?

Good hunting.

Kind regards. Mark

Large Alder Sawfly, Ashdown Forest (18 September 2011)

[Pete Eeles]

yep - Knot Grass and sawfly.

Cheers,

- Pete

[Michaeljf]

The Knot Grass caterpillars seemed to be doing well round here as well this weekend - I came across two as I was walking out the back. Speaking of moth caterpillars, last weekend (I think it was last weekend) I visited Parc Penallta (Ystrad Mynach) briefly and saw how many of the small willows had been stripped of their leaves. There were a few batches of Buff-Tip caterpillars still eating (quite late in the season, they'd all be finished & pupated by now near the coast of South Wales). I don't know if all the munching at Parc Penallta had been done by the species, but I'm guessing it must be a great place for moths .

Michael