Black caterpillar with yellow dots on its sides, and blue/white legs. About 4-5cm in length.
Sat, Nov 15, 2008 at 9:32 AM
Hey there!
I was doing some wetland classification earlier this fall (early September), and I happened to stumble upon this little guy in the afternoon. I found him south of Blackwater, in the Beeverton wetland located one and a half hours west of Peterborough Ontario. He was on a tall shrub located along side of an abandoned railway. He’s solid black with yellow spiracles on both of his sides. He also had blue/white abdominal prolegs and solid black thoratic legs. He’s hairless and quite shiny. Hope the picture helps!
Erin G
Beeverton Wetland (Blackwater)

Sawfly Larva

Sawfly Larva

Hi Erin,
We believe this is a Sawfly Larva, and not a caterpillar. We have searched through countless images on Bugguide and could not find an exact match, but we did find one example that was similar. Sawflies are known for striking the pose exhibited in your photograph when they are threatened or otherwise bothered. We will contact Eric Eaton for a second opinion, and also to see if he can give a quick method of distinguishing between caterpillars and sawflies.

Hi Bugman:
This looks like it could be a Willow Sawfly (Nematus ventralis), or a closely related species.  More photos at: Link1 and Link2 .


One Response to Willow Sawfly Larva

  1. Tricia says:

    Are they harmful. We have them.

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