Subject: Unknown Pinkish Caterpillar
Geographic location of the bug: Motley, MN on a 22acre island on Lake Shamineau
Time: 11:06 PM EDT
Your letter to the bugman: Dear Bugman,
My sons and I were on a Father/Son retreat and we discovered this pinkish caterpillar w/ one long black strip down its back from its head to its rear-end. It also had several black stripes that ran perpendicular to its one long black stripe. The total caterpillar length was roughly 1 and 3/4 inch in length. We know that their are likely many undiscovered insects and maybe caterpillars. We’re wondering if the caterpillar we discovered on a small tree branch is already identified as we could not find it when searching for caterpillars in MN. The photo attached is in my Sons terrarium and the red mushroom looking thing next to it is only a decoration. We didn’t want to touch the caterpillar for a better picture for fear of a sting, or rash.
How you want your letter signed: Sincerely, Richard Parkos and Sons
Thanks for clarifying the identity of that red decoration with the spots. As we were formatting the image and color correcting it for posting, we obsessed on its identity. This is not a caterpillar. We suspected it to be a Sawfly Larva, but the markings are unusual, but our internet search produced several images that confirm our suspicions that this is the larva of an Elm Sawfly. We have received images in the past of Elm Sawfly larvae that are yellow, green or pink, and they have a black stripe running the length of the body on the dorsal surface, but those traverse stripes are unusual. There is a small image on the Wisconsin Department of Natural Resources website with a caption that indicates “Elm sawfly larvae are typically yellow; it is uncommon to find the pink form” but it does not mention the traverse stripes. Additional images on Insects Galore and Forestry Images also document these unusual markings. The adult Elm Sawfly is a non-stinging relative of wasps and bees. Elm Sawfly larvae will not sting and they will not produce a rash.