Marianne's Response

Rose chafer and Japanese beetles on peony bushes

Peonies are my favorite flowers. For the last several years mine have set lovely buds. Shortly after the buds begin to grow and get full I find a number of them with shot holes which ruin the buds. My largest plant had about 10 blossoms and I have lost 5 buds in the last few days. I have never been able to find any sign of pests but finally the other day I found a few little brown blobs – probably 1/8 – 1/16th inch long. I am not sure if they were a bug dropping or perhaps the bug itself. I squished the few I saw, but still had more damage this morning. This has me so frustrated. Any ideas? I did put some sort of horticultural oil on the plants a week or so ago, but it rained hard shortly after I applied it. I bought some sort of dust last night with Carbyl (SIC??) will that help? I try to avoid pesticides at nearly all cost but I am ready to try most anything to save a few of these peonies. I am wondering if it is something that is overwintering on the plant?

Posted by lisann on April 26, 2014

Marianne's Response

Your peony buds look like they have been attacked by the rose chafer or perhaps a Japanese beetle. The simple solution is to hand pick these beetles when they are feeding early in the morning and be sure to look under the leave and the cracks of the leaf joints where they like to hide. Drop the beetles into a bucket of soapy water. I am not sure if the pesticide dust that you purchased will kill rose chafers and Japanese beetles. Just check the label of any insecticide and it will list the pests that it controls. Cut your peonies back in the fall and clean up around the base of the plant to discourage any overwintering of these pests. Keep growing, Marianne Binetti

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