What's That Bug? does not endorse extermination

What’s that caterpillar?
August 14, 2009
Hi —
I love your site and browse it for pleasure when I have time. One damp, overcast morning in August I found an outbreak of these caterpillars on the leaves of my red-bark dogwood shrubs. We live outside of Philadelphia, PA and have had an incredibly wet summer. Any ideas?
Thanks!
Betsy
Merion Station, PA

Dogwood Sawfly Larvae
Dogwood Sawfly Larvae

Hi Betsy,
These are not Caterpillars, but that is a very easy mistake to make.  These are the larvae of Dogwood Sawflies in the genus Macremphytus.  We are linking to a matching photo on BugGuidePenn State Woody Ornamental Integrated Pest Management website has a wonderful explanation of the life cycle of the Dogwood Sawfly.  It states:  “Dogwood Sawfly, Macremphytus tarsatus, is a significant pest to dogwood (Cornus) species. Because the Dogwood Sawfly takes on several forms while in the larval stage, it may not be easy to identify. Even the first instars can devour small portions of leaves, with groups of them producing a skeletonized appearance to the leaves. However, the larger final instar can consume entire leaves, leaving only the tougher leaf midribs.”

What's That Bug? does not endorse extermination

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