Plum Curculio


@scottfsmith, How big do you consider fruits have to be to be out of curculio’s damage?


There is no hard and fast rule there as it depends on what other fruits are available, etc. But for apples I would say by dime-size there is very little activity, and even by chick pea size there is less interest than pea-size. For plums, round plums they can like at a bit bigger size but by nickel they are really losing interest. Plums that are not round they are willing to go after much later, often biting by the neck on quarter-sized fruits. Coe’s Golden Drop is one they really like to give neck bites on.

Since Surround is a pain to spray I like to stop as early as I can, so I pay attention to this. It is raining now and I have a few apples that are still not big enough and I plan on coating them along with the non-round plums and some peaches still too small.


Thank you, that is invaluable information, specially for stone fruits.


I sprayed today for the 1st time. Seems late for here. Had a few sweet cherries that have already been hit and saw some apricots (didn’t know i had any) way up on a branch that might have hits on them…everything else is just at petal fall --plums/pluots…probably about right on spraying those.

I spray just pure permethrin (mixed with water…thinks its 2oz to a gallon).


I’m thinning and bagging today. Still unsure whether all PC bitten apples are doomed to fall off the tree therefore should be thinned. Or whether the PC larvae gets squished and the apple stays on the tree, making an edible but maybe deformed apple.

You’d think I’d have this figured out by now but I don’t. Thanks for help.


I have sprayed two rounds of triazicide on my peach and plum trees since their petal fall ( based on each individual tree’s stages). So far, no plum Curculio damage at all!

Maybe I will finally harvest plum this year!:yum::yum::yum:


Because it is not an exact science. With fruit that have insect holes on them but still hang on trees, it does not mean they are totally ruined. I have been surprised many times that they have only skin deep damage. These include damage on peaches.


Do both these look like PC? Top one definitely round, not crescent shaped bite.



The small one looked like a crescent mark that was dried up. If you want, you could have kept that one on the tree, with pears, the internal damage is often not total. You can always cut damaged chunk away and eat the rest,

I don’t like the dent on the bigger one. A dent like that often means the flesh is corked.


Thanks. These are Black Limbertwig apples.

What do you think bit the top one?


I don’t know. Hopefully, those who know will chime in.

I have Black LT and Casey LT flowered this year. I have Victoria somewhere but I may have lost a tag. I heard that Black LT ripens late. Mine probably won’t ripen in time. If it does not ripen intime, I will remove it,


BLT ripens mid October here in zone 7. Hope it works for you.


I’ve heard it tastes good. I should call it Gold Rush of Limbertwig. Good tasting but is quite late (sometimes, too late) for my zone 6a. Just like Gold Rush.


Sevin (zeta-cypermethrin formula) plus a sticker (Bonide turbo)has worked very well this year. Almost no strikes on trees I sprayed. One tree I didn’t spray because it had a bunch of lady bugs, and then some lady bug larvae. Every fruit on that tree had at least one hit, and some multiple bites.
From the limited research I’ve done, one downside to this is that it does appear to be very hard on bees, if sprayed during bloom. Of course I didn’t spray then but it makes me wonder what other beneficials are harmed.


I reused my Clemson bags too.


Sevin is also a thinner for apple trees …or so i think.


Carbaryl is a thinner for apples, not the newer formulation of Sevin.

Sometimes I wish I could still use Carbaryl for thinning


If my plums ever set a good crop I will be spraying also.


When thinning, do you keep the apples with a PC mark or cull them?

Do you take culls and drops out of the orchard? I have deep mulch and drops disappear in it. Maybe will convert to bare soil underneath but then have to use Roundup that am trying to minimize.


They can ravage plums if given the chance. Apples can a lot of times handle curc bites (the apples grow and crush the eggs)…i’ve never sprayed pears for curcs…too dense.

If you get to the hit early enough…you can use a sharp razor blade/scapel and just cut it right out. The fruit will heal up just fine and no more egg in there. I’ve done this in the past to salvage a few fruits just because i wanted to try them.