Worms in plums - Ask Extension
I have two Black Ice Plum trees in my yard. I planted them about 6 years ago. I’ve been babying them and trying my best to prune correctly. Last yea...
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Worms in plums #838105
Asked June 28, 2023, 3:14 PM EDT
I have two Black Ice Plum trees in my yard. I planted them about 6 years ago. I’ve been babying them and trying my best to prune correctly. Last year was the first year they really produced fruit. I harvested a few large bowls of plums and was so excited – until I cut into them… Inside almost every plum (except maybe 10) I found white “worms” that were alive. I am wondering what this might be? And how can I treat it? Or maybe you can point me in the right direction for learning more.
The trees are totally organic. I haven’t put any chemicals on them – even organic fertilizer. But the fruit that had the worms had holes or scarring on the outside of the fruit. So I’m assuming they will need to be sprayed with something.
Gogebic County Michigan
Expert Response
Hello. Those are plum curculio larvae. Here is a link to see what they look like... they love all stone fruit, particularly those that are not sprayed.
https://www.canr.msu.edu/ipm/diseases/plum_curculio
There are sprays you can put on to protect the fruit, but unfortunately organic options do not work (we have tested all of them). Sevin, pyrethroids will kill the adults when they go to lay their eggs in the fruit. The best timing for application is a 'shuck split' or when the small fruit emerges from the remaining flower parts.