Controlling plum curculio on peach tree

I had a hectic week dealing with plum curculio to save my peaches. My seed grown peach tree bloomed from late March to early April this year. There were a little over 100 peaches growing rapidly. Then in early May, I found the first PC on the tree and a few damaged fruits and within 3 days half of the fruits have marks on them. I panicked and tried the following measures but no chemical spray yet.:

Taping at the base of trunk ( nothing, too late to do that)
Tapping the tree in the morning ( got one)
Hand picking of fruits at night ( got 10)

I haven't seen another in the last two days so maybe the overwintering bugs have done their things.

Of the 100 fruits or so, I did a quick and dirty analysis on them:
                 Condition.           Size.                        Number
Group 1.   Not damaged.    1 to 1.25 inch long. 25
Group 2.  Minor damage.   1 to 1.25 inch.          50
Group 3.  Severe damage.  0.5 to 1 inch.            10
Group 4.  Not developing.  Less then 0.5 inch.   15

I don't see any fruit drop but I am expecting group 3 and 4 to terminate developing and drop eventually ( june drop).
I put some mesh bags on a dozen healthy peaches for protection. For group 2 peaches, they are still growing quickly so maybe they can outgrow the larvae at the pit hardening stage.

I am estimating I missed the window to detect and control PC by a week or more. The damage was happening so fast and I should've been more prepared. Hopefully I will do better next year.

How you run into PC on your fruit trees? If yes, usually On what fruit developing stage? What organic measures do you take and how effective are they?

May, the plum curculio is the bane of my cherry tree!  I assume it will also vex my newly-planted apple trees when they start to fruit.

I’ve tried the things you listed.  I have a collar around the trunk that I spread with tanglefoot. Seems to get less damage, but doesn’t totally solve the problem (I guess because they can climb on from adjacent plants). Shaking the tree only occasionally knocks one out and it’s really not fun for me. “Jarring” the tree by hitting it with a stick damaged the bark so I stopped that.

I have resigned myself to hand-picking the damaged fruit as early as I see the tell-tale marks and disposing of them in a way that will keep the larva from developing into a new generation. I estimate 20-25% I discard this way. I have tried to reframe my thinking to not see this as “loss.” Rather, any crop I harvest is an unexpected bounty and culling the damaged fruit is just one step in producing that bounty.

I remove group 3 & 4 immediately and remove group 2 from tree to ripen and prosses for jam to try to get all larva.   Trees usually over produce  so thinning and pruning back excess limbs results in larger and better fruit.

My tree is basically free, still it is upsetting to see so many fruits lost due to my negligence.

I disposed of the smallest ones but still leave the injured ones on the tree for the time being. I plan on dissecting one every few days to see the larvae damage inside. And hopefully some fruits just have feeding wounds and no eggs so they will make it to maturity.

I feel your pain with the curculio. We have the curculio bad here too, and my seedling peach that is fruiting seems to also be very susceptible to it.

I'm looking to breed resistance to curculio into my future peach seedlings. A peach seedling that I found growing in my area is naturally resistant to it, and produced a huge amount of almost completely pest free peaches (which is unheard of in this area being unsprayed).

That tree however is susceptible to bacterial spot and suffers even though it is pest free. My seedling peach however appears to be completely resistant to black spot though and other diseases here, will grow in wetter soil, and is a vigorous grower with a natural open shape.

I'm really interested to try crossing these two trees to try to create an extremely pest and disease resistant peach tree that will hopefully produce huge crops of tasty peaches free of both pests and diseases with no work required.

Here's a few pictures of the curculio resistant but bacterial spot susceptible peach. You can see some of the bacterial spot in the second picture (the black dots).

For future years research nematodes.

If it is still happening you can partially protect by repeatedly spraying the tree with the proper clay mixture leaving it looking whitish to grayish.  They are typically Kaolin or Bentonite based with a bit of other stuff to improve binding and water fastness.  Completely spray the tree as the leaves and fruit grow repeating as necessary.  Apparently the insects don't like the feel of trees so treated.   There are versions of this that qualify as organic and others have stuff mixed with it that doesn't qualify.  Here is a gurneys link but many versions from many makers are available.

plant protectant.

Steve Thorn wrote: A peach seedling that I found growing in my area is naturally resistant to it, and produced a huge amount of almost completely pest free peaches (which is unheard of in this area being unsprayed).

That's a rare find. Your plan sounds very promising.  Hopefully you will get the dream peach tree in just a few years.

C. Letellier wrote:For future years research nematodes.

If it is still happening you can partially protect by repeatedly spraying the tree with the proper clay mixture leaving it looking whitish to grayish.  They are typically Kaolin or Bentonite based with a bit of other stuff to improve binding and water fastness.  Completely spray the tree as the leaves and fruit grow repeating as necessary.  Apparently the insects don't like the feel of trees so treated.   There are versions of this that qualify as organic and others have stuff mixed with it that doesn't qualify.  Here is a gurneys link but many versions from many makers are available.

plant protectant.

Do you mean strain specific nematode controlling PC in soil?
Kaolin clay sounds promising for protecting my other seedlings too, they got hit hard by cucumber beetles and flee beetles now.

Here is the update.

Over 90% of fruits were lost to PC. About half of them only had feeding wounds and were able to keep on growing into the S3 stage. With the increase of sugar content, they finally had brown rots. The few remaining ones were bagged early on and they are changing the color right now. But unfortunately, when I took the bags off, they were attacked by leaf-footed bugs.

I tasted a couple unripe fruits. They were still very firm but had good flavor already. Semi cling with light yellow flesh. The biggest peach is over 2.5" in diameter or 21cm in circumference now (100 days) and is still growing. I am trying to keep it ripening in the tree as long as possible.

Adding to my previous reply: Because my worst problem is the peach leaf curl and it is best controlled by keeping the tree dry I have my trees in a high tunnel made from abandoned portable garages. some of them come with screened side walls so that reduces the curculio flies and they prefer the non fuzzy plums anyway so the peaches have little problem.   I should have removed the cover during snow season so now I have to rebuild the covering.

I noticed with better soil quality this year my vegetables have no powdery mildew and fewer aphids. I never tried to improve soil around the peach tree. I am wondering if healthy soil will make the tree more PC resistant.

Hans Quistorff wrote:Adding to my previous reply: Because my worst problem is the peach leaf curl and it is best controlled by keeping the tree dry I have my trees in a high tunnel made from abandoned portable garages. some of them come with screened side walls so that reduces the curculio flies and they prefer the non fuzzy plums anyway so the peaches have little problem.   I should have removed the cover during snow season so now I have to rebuild the covering.

My tree had leaf curl too but only in mid spring when weather was wet. Only some leaves in the center were affected. I can imagine it's hard to deal with if the disease spreads to more leaves.

Curculio lay eggs at fruit set so early early action is the only way to prevent that damage.

The method I used was to knock the tree/branches at bloom and gather any curculio onto a sheet...continue daily.  I did it for days/weeks until I didn't catch any more for awhile.

The year I used tanglefoot on yellow card stock I caught some and that seemed to work also but I only tried it the one year.

Many times the peaches will reach full size and even ripen while the larva is damaging the area around the pit so sometimes there are tasty bts in spite of this critter

Thanks Judith for the advice. Last year lots of peaches made it to the last few weeks. But when they sweetened up the wounds caused by curculio feeding got fungal infection and the whole fruit turned brown and moldy.
I have no peach bloom at all this year so maybe that will break the curculio life cycle. I will try catching the bugs early next year.

I'm in the middle of Michael Phillips' "The Holistic Orchard". A great resource, and he mentions curculio and potential control tactics so much that I keep getting a rhyming Phil Collins song (of which I only know the eponymous lyric) stuck in my head. One of my conclusions from how much eastern growers have to fight curculio is that I am glad to live where Mr. Phillips quotes Luther Burbank as saying is "the best place on Earth to grow fruit" (coastal Northern California). Phillips seems to use trap trees and bulk supermarket fruit as traps for curculio and other pests, as well as diverse flowers and habitat for controlling predators/parasites of the curculio. Now that song is stuck in my head again;)