Unidentified Caterpillar

[jdoherty]

I took this photo of a caterpillar in Monkstown Wood, Newtownabbey, N.Ireland in Sept 2007.It was about the size of a 10p. ID anyone?

Thanks, John.

[Dogghound]

It's the larva of a sawfly (Symphyta), what plant was it on?

[jdoherty]

Sorry can't remember the plant (even if I could recognise it) apart from the fact that is was low on the ground with no flowers.

John

[poschiavanus]

This is one stunning picture of a sawfly larva.

The single eye, more than 4 pairs of prolegs, and the way in which the body is creased into a number of folds are all useful ways to separate from larval leps.

There appear to be a few characteristics which can be noted from the image:

• 7 folds on each abdominal segments. There is a pattern of a fold with white pinacula, a fold without, another with white pinacula, repeated and followed by two more without, giving 7 altogether. Please note that this may not reflect the true order within a segment, rather it was the way in which I recognised the pattern.
• apparently 6 pairs of abdominal prolegs.
• Pinacula appear to have characteristic distribution, 3 each side on first and third fold, a single one low down (= more ventrally) on fourth fold, and three with the third again placed low down on the fifth fold.
• Colour pattern on head and body.

Its just a shame you didn't note the plant, as this would have narrowed down the possibilities.

With the key available to me all I can say at this point is that it is most likely a member of the subfamilies Tenthredinae or Selandrinae of the largest sawfly family Tenthredidae, with the former more probable.

HTH,

poschiavanus

[jdoherty]

Thanks poschiavanus for all the information. It brings the picture to life when you have so much background information. I know, to see, the type of plant it was on. I just have to get a pic of it for ID purposes. I'll have a look through my archive and if I find a pic of the plant I will post it here.

John