Insects make the most of their short lives, and it’s unusual to be able to visit them over a period of weeks. But the Dogwood Sawfly (Macremphytus tarsatus) larvae featured here made a comfortable home above one of the bridges in the water garden area of the arboretum for about six weeks from mid-September into late October.
I was looking for the Dogwood Spittlebug featured in the last column when I first saw these small, caterpillar-like larva curled up under the dogwood leaves. There were about two dozen of them, resembling tiny, sugar-dusted curls.
Sawflies are in the Hymenoptera order with wasps. Unlike bees and wasps though, sawflies have a larval stage that’s a lot like a butterfly or moth. These particular larvae eat dogwood leaves, but they don’t typically harm the trees, because they feast toward the end of the season.
When I returned to the spot a few weeks later, the larva had munched their way through several leaves, moving down the branch as they cleared each leaf to its nub. One or two of the sawflies was pure yellow, without the white, waxy coat.
By mid-October I could only find a few individuals, and they’d shed their white skin to reach the final larval stage: a striking black and white pattern atop an apricot yellow base. Dogwood Sawfly larvae cozy up in decayed wood over the winter and become pupae in the spring.
The adult, which emerges in the summer, is a striking rust-colored wasp mimic, with white-tipped antennae. There’s a nice photo of an adult Macremphytus lovetti linked below. Be sure to visit the pond area to look for them in 2025.
Stay curious!
See more of Karen’s work here.
Sources:
- Life cycle information from Sawfly GenUS: https://idtools.org/sawfly/index.cfm?packageID=89&entityID=839. Accessed 11/5/24
- Nice photo of an adult western dogwood sawfly on BugGuide: https://bugguide.net/node/view/677497. Accessed 11/5/24.