What's That Bug? does not endorse extermination

White powdery caterpillars devouring my dogwood!
The culprits look like bird droppings when curled up in a circle under the leaves. When eating (aggressively) they are 11/2 inch long caterpillars with black and white heads and a powdery coating that stuck to me when I pruned and removed leaves with pests and eggs! I sprayed the shrub and the next day there were more! One caterpillar was gold coloured-before or after the powdery coating?? Please help!
Kathy Ferguson
Goderich, (Southern) Ontario, Canada

Hi Kathy,
These are Dogwood Sawflies, Macremphytus tarsatus (or one of two other closely related species in the genus that are difficult to distinguish from one another), and they are related to wasps, so they are not Caterpillars. Dogwood Sawflies, according to BugGuide, have larvae that: “start out covered with a powdery waxy white coating, which they shed later in the year to become yellow with black cross-stripes or spots on top. “

What's That Bug? does not endorse extermination
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2 Responses to Dogwood Sawfly Larvae

  1. Howard Holt says:

    These larvae are just appearing on the many Gray dogwoods we have in our woods in one location right behind our shed. The last time there was an infestation, most of the dogwoods in my woods were decimated, but this was about 6-7 years ago. Since then there have been none of these larvae and the Gray dogwoods have thrived again, so I was surprised to see a couple of skeleton dogwoods finding the dried up chalky coverings on them then insepecting others nearby and finding a couple to a few curled up under the leaves inactive but alive and all with that powdery white coating. I dont spray poisons into the environment or use them at all, so I just hand pick them and throw them into the pond. Will have to observe if any frogs eat them!

  2. Linda Gee says:

    So what do I do with them. Will Sevin kill them and will they spread to other plants? They are too thick to pick off. They are eating the red dogwood shrubs.

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