Elm Sawfly

Catch and release
Location: Extreme NE Montana
June 7, 2011 12:24 am
Dear Mr. Bugman,
I have lived in this region nearly my whole life and I have never seen this creature before. I am so glad I spotted it before mowing it over. We captured it, which was easy, took pictures of it, and released it into the great wilderness. I hope you can help identify this creature!
Signature: Creature releaser

Elm Sawfly

Hi Creature releaser,
This impressive insect is an Elm Sawfly,
Cimbex americana.  BugGuide describes it as:  “The largest North American sawfly with larvae reaching almost two inches. Larvae are a yellowish-white color and possess a black dorsal stripe. While feeding, the larvae usually coil their posterior around a leaf or twig. At rest the larvae roll into a characteristic tight coil. The larvae spin tough, papery cocoons in the litter or just below the surface of the soil. Pink coloration is not common, most larvae are green to yellow in color.  Adult has glabrous thorax with white/yellow spot above, orange antennae.”  If the larvae, which are frequently mistaken for caterpillars, are very numerous, they can defoliate small trees in gardens, but the species is not considered to be a problem in forest situations.

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