hollyhock pest; calhoun co EMG training exercise fall 2020

Asked November 9, 2020, 1:28 PM EST

I was so happy to see several hollyhocks grow from seeds at my house this year and look forward to future years' blossoms. However I hae noticed some weird things happening to some leaves. First there were wandering paths of a lighter geen on some leaves. It was really a pretty design but I figured it might be an insect. I could not see any insect. My son sprayed neem oil on some of them, which didn't seem to help. Now some of the leaves have tiny yellow polkadots. On the underside they are raised, like a pimple. Do you now what they might be? I don't think i know how to send you a picture but if needed I'll ask my step-daughter for help.
Do you now what this is? And what I should do ?
Thank you, MM

Ingham County Michigan

1 Response

Based on the first description, I think leaf miners are causing the "wandering paths" on the leaves. There are various leaf miner types - flies, wasps, etc. - but all are the larval form of these insects. They are also quite small (they have to be because they are "mining" in between the layer of leaf tissue), so that is why it was difficult to see them. They are not a serious pest and the damage is usually just cosmetic. You can read more about them here: https://www.canr.msu.edu/resources/leafminers

I am not sure what is causing the second set of symptoms. If you could send a photo - that would be very helpful.

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