For many plants, it's the season to be eaten. I have been patrolling the shaded Mail Trace road along our bluffs, looking for what is chewing what. This shrub caught my eye with several large branches whose leaves were completely skeletonized. There were a few remaining leaves that were healthy, but turning them over revealed masses of larvae packed tightly together on the underside, hiding from the midday sun and predators. Other branches were unaffected and Barb identified it as gray dogwood, Cornus foemina, a common shrub along the lane.
For me, the chase to identify a species is half the fun. I sent this photograph to INaturalist and its first choice was Macremphytus testaceus, a sawfly. Googling that mouthful (thank heavens for cut and paste) and Bugguide listed its food source as Cornus sp. BINGO!
The first photograph I found of the larva was bright orange with crisp
black spots. It does a Cinderella like costume change from
the second instar which is covered in a white waxy covering. They tend to
hide out in the daytime and munch away at night. Here they are in this video when annoyed and escaping.
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| Last instar - Fyn Kynd CC |
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| Sawfly - Tom Murray CC |
Sawflies are actually in the wasp family as we discussed in this blog a few weeks ago. As usual, I checked Bugtracks and as usual Charley Eiseman had a great story which I quote:
"I once tried to raise these larvae, and had them in a Ziploc-type bag by my desk. One night when sitting at my desk, I noticed some motion across the room out of the corner of my eye. When I went over to investigate, I discovered that one of the larvae had chewed its way out of the plastic bag and had been trying to bore into the windowsill when it fell into a spider web, from which it was now struggling to free itself. I later found a small pile of sawdust under a nearby chair, which the larva had evidently tried boring into before heading for the windowsill. It turns out that Macremphytus species burrow into dead wood to overwinter and pupate."
I am currently raising my specimens in hard plastic containers but checking them regularly.
