Tuesday, 27 May 2014

Help needed with a caterpillar

I found 2 of these on Bird's Foot Trefoil this evening.  I think they're Six-spot Burnet but can anyone confirm?  Also, could someone tell me the difference between a Five-spot and a Six-spot Burnet caterpillar please, just so I know what to look for.

Six-spot Burnet caterpillar?


  1. Hi Sarah, no cat book with me, but try this link http://www.ukleps.org/Ipadv1.html if you haven't done already that is.
    Best of luck with it...I do find them difficult!

  2. Thanks Ina. I've checked various websites including the one mentioned. I also have Jim Porter's book but I just don't understand the difference. According to the book, the only differences I can see are size (6-spot 18-22mm, 5-spot 16-20mm) and body colour (6-spot greenish-yellow or yellow, 5-spot pale whitish-green often with a yellowish tint). The rest of the descriptions sound the same to me. Confused!

  3. We've recently had the same discussion in Glamorgan and come to the conclusion that they can't be reliably separated as larvae.


  4. Thanks George. I'll just have to see what's flying later in the year....

  5. Peter asked me to comment, although I don't think I can help with your specific question as I can't tell Five-spot and Six-spot larvae apart either!

    Our problem over here in the Thames Valley has been trying to separate the two five-spotted species. Traditionally we've had nothing to worry about "because we only get Narrow-bordered Five-spot", but over the last few years that's proved not to be the case and some discrete colonies of Five-spot have been now confirmed. The differences appear to be:

    Eggs: 5-spot laid in a heap, NB5-spot in a single layer
    Larvae: 5-spot with shortish hairs, NB5-spot with long hairs (see www.ukleps.org)
    Cocoon: 5-spot 'closer to the ground' (not sure how helpful that is!)
    Adult: 5-spot has significantly greater incidence of combined spots (f. minoides) and in our area they've proved to be the majority at any one site.

    I'm not sure what the five-spotted situation is in Ceredigion, but you could usefully look for long-haired larvae to confirm NB5-spot.

  6. Thanks for all the info Dave.