Plum Curculio (PC) Questions and tips

Good point on plums (I edited my post).

I admit I cut up so many damaged fruit. My memory may be fuzzy but I think PC larvae make a straight line to the center of the fruit. Then, there are coddling moths and OFM aiming at the same fruit.

1 Like

The feeding scar is just a round divot. The egg laying have the crescent which is designed to keep the growing fruit from crushing the egg. They only make crescents after laying the egg so if you see a crescent there is an egg.


About a week after petal fall on my plums I discovered the crescents. I sprayed them with imidan about two days later. I never saw the PC but they hide good. Would that spraying I did kill the adults on the tree and would it kill the eggs or developing worm. How soon should I follow up with a second spraying? Should have I sprayed the ground where the adults may be emerging?

1 Like

You can take a razor and cut out the crescent part to remove the egg and save the fruits if you don’t have many. The fruits will have a big scar when ripen but they are still good.


I was going to ask if anyone does this. Good to know it works. On trees with only a small number of fruits, I think it would be worthwhile. Better than getting no fruits at all.

Since some PC crawl up trunks and some fly to canopy, and this appears to be somewhat temperature and time related from what I have read…
Is it helpful to wrap a portion of the trunk and apply Tanglefoot? I was wondering if this could help with timing of sprays if you observe PCs caught in the Tanglefoot, then you might have another clue that their emergence/activity is increasing?


Some fruits got hit around 3 to 6 hits then there are no way to cut all those eggs out. Sad!


I have a few small speciality branches with only a couple of fruit. I may try cutting them out.


oh gosh! that’s terrible! Like @Graftman, I have some trees/grafts, mostly some plums and peaches that may only have a few fruits this year- if they set fruit at all. This would totally be worth trying if my sprays are not effective.

1 Like

I believe this is an example of a PC scar on apple that is only skin-deep.


I went back tonight and checked . . . and I could not find any more damaged fruit. I think my Monday spray paused their activity for a time. These are nasty little things! :angry:

1 Like

I distribute Kootenay Fruit Covers all over the United States, see I know they work on a variety of insects, including codling moth, OFM, and cherry fruit flies, because I have used them to that effect in my own orchard. However, I do not have PC in my orchard, thank heavens. I am looking for three or four growers who do have PC in their orchards. I would like to do a variety of tests in orchards where PC is present to confirm whether or not the covers work against PC. If you would like to be part of one of those tests and you have PC in your orchard, please message me or contact me through the website. The company email is UPDATE: I have had several inquiries, which I appreciate very much. I have a few more spots to participate in our field tests. If you are interested in participating, please send me a message at my company email.

Scott, have you seen them yet this year?

And squirrels, deer, voles, birds…it’s a wonder that my ancestors in the Shenandoah Valley didn’t all starve without having the chemical controls we have.

Not yet… it has been so cold recently that I am not looking much. In the next warm spell I expect they will come out.

The great whitening of my trees and bushes has begun. With temps staying warmer for the next few nights I didn’t want to wait any longer so I sprayed my surround on my romance cherries and peaches as the primary target, plus my single apricot still hanging on. Then I also made a quick round on my apples and pears. I put some spinosad in the tank, plus a little liquie castile soap as well as a couple eggs blended up with some water to hopefully repel the deer from browsing. Hopefully none of that conflicts.

I did 3 cups per gallon of water for the first tank, then went to 4 cups per gallon for the next one since it always seems hard to get much to stick with the first spray.

1 Like

Your timing is perfect. I have a lot of trees so have been working up to it but everything covered as of yesterday. Tonight the curc will be out in force… she goes 0 to 60 in the blink of an eye.

I really should do one more coat on a few things for insurance, plus a few things that just dropped petals I’m going to patrol here in a few minutes to see if I need to get my headlamp on for a round of spraying.

1 Like

I read on the Penn State Extension that PC control coincides with apple petal fall. Has anyone ever noticed this?

Article states, “The timing of an insecticide application after the petal fall stage on apples is almost always perfectly synchronized with the optimal period for the control of European apple sawfly (EAS), rosy apple aphid (RAA), Oriental fruit moth (OFM), and plum curculio (PC).”

1 Like

Yes, as soon as the petals fall and you have a warm night the curc will be on your apples.

They are out, here is one I found in my orchard tonight on an asian pear. Crushed about 5 seconds after this picture was taken.

My coverage generally looks good but it could use some spot spraying. I’m tired so the curc will get a few fruits tonight.

Wow, sorry to see that curc on a fruit with what seems like a pretty good surround coverage to me. Do you usually target fuller coverage than that on the fruit?