Knowledgebase

What is eating the leaves on my astilbe plants? #744737

Asked April 16, 2021, 9:43 PM EDT

I have astilbe plants in varies gardens around our property. All do well except the ones planted in a garden under a large Japanese Tree Lilac. They come back every year, but they never get very tall - just a few inches tall - and something eats the leaves. I checked with the garden store in our area and they told me to treat for slugs did work. Then they recommended Bonide eight insect control. Nothing! I did notice very small flies with opaque wings, but no one knew what they were. HELP, please!

Washington County Minnesota

Expert Response

We can't be sure what's damaging the astilbe plants without seeing the pests or sharp photos.

However, the pattern of the leaf damage suggests the pests might be black vine weevils.  The weevils make distinctive notch-like cuts on leaf edges and the weevils are known to feed on astilbes. Vine weevil larvae feed on the roots.  This could account for the plants' failure to thrive.

Adult vine weevils feed at night so it might be necessary to check the plants after dark to see if any are present.

This document discusses astilbe pests including vine weevils:
https://portal.ct.gov/CAES/Plant-Pest-Handbook/pphA/Astilbe-Astilbe


Learn more here:

https://pddc.wisc.edu/2015/07/06/black-vine-weevil/

An Ask Extension Expert Replied April 16, 2021, 11:26 PM EDT

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