Multiple perennials, insect damage - Ask Extension
Insects are damaging several of my perennials. There is a distinctive pattern of brown, sort-of-squares on the leaves before they get chewed through. ...
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Multiple perennials, insect damage #874308
Asked June 23, 2024, 3:21 PM EDT
Insects are damaging several of my perennials. There is a distinctive pattern of brown, sort-of-squares on the leaves before they get chewed through. This appears on Ampelopsis Vine, Blazing Star, Hyssop, Russian Sage, Culver’s Root, Globe Thistle and Ligularia. I have a photo of a yellow and black bug similar to a Woodbine Borer in the Hyssop. Also an orange and black bug, please see PDF.
On Rudbeckia and Salvia there are holes. They don’t appear to have the same distinctive pattern. I have photos of an orange bug on the Salvia but also on the Russian Sage. Please see 2nd PDF.
I have a Yarrow that is a wilting — no sign of bugs, it bloomed like crazy last year, this year, not hardly growing. Maybe it does have that same pattern, just can't see for the size of the leaves.
I have a number of plants for butterflies and bees, so don’t want to use any insecticide that would harm them. I have been trying to control aphids on butterfly weed with insecticidal soap, but don't know what to use for this other problem(s).
Thank you for your attention and expertise!
Ramsey County Minnesota
Expert Response
Your biggest problem is the four-lined plant bug. The good news is they are about at the end of their feeding cycle. You've got photos of both the adult and the nymph and classic damage. Read here:
https://extension.umn.edu/yard-and-garden-insects/four-lined-plant-bugs
The ladybeetle indicates the presence of aphids and the curled leaves on the rudbeckia is also indicative of aphids. Look for sticky honeydew on the leaves. I think this is the lesser of the problems you have (the four-lined plant bug damage is worse), but you should get ahead of the problem if you've got aphids:
https://extension.umn.edu/yard-and-garden-insects/aphids
https://extension.umn.edu/yard-and-garden-insects/four-lined-plant-bugs
The ladybeetle indicates the presence of aphids and the curled leaves on the rudbeckia is also indicative of aphids. Look for sticky honeydew on the leaves. I think this is the lesser of the problems you have (the four-lined plant bug damage is worse), but you should get ahead of the problem if you've got aphids:
https://extension.umn.edu/yard-and-garden-insects/aphids