We have been very successful in encouraging the PC population in se Michigan. 
Now that we are spending more time cleaning up their damage than enjoying our fruit trees, does anyone have advice on plumb curculio management? They seem to damage most of our plumb, apple, some peach, and just a few pears.
Thank you in advance
So last year was my first year with apples, and I was not prepared at all to deal with them. I will be starting a more diligent spray program, but I plan to avoid synthetic insecticides for the time being. I know several members on here report success with Surround, a clay product, which is mostly an annoyance for the plum curculio as they donāt like to walk on apple trees coated with that clay. I have heard it can be labor intensive to keep a good coating on the trees.
I bagged apples last year, which worked quite well for me. Once I saw damage from plum curculio on my fruit, I bagged everything that was undamaged. Since it was just my first year, that was only a handful of apples. It would be quite tedious to do on a large scale. However, no further bug damage to any of my apples! I used a product called āmaggot barriersā which look like a pantyhose type material. This year I am going to try a mix of the maggot barriers and the organza bag type bags. The organza style bags are nice because they have drawstrings built in. It will be important to bag the apples as early as I can, though, as the plum curculio around me started damaging the apples almost right after petal fall.
Hope that helps!
Too true! By the time you finish bagging the fruit, the curculios have already had their way with it.
I see I have posted on this topic at least eight times over the last seven years. I never learn.
Free ranging poultry consume several insect pests of apples although they are more effective against those that spend time on the ground such as plum curculios do, so, if this is an option for you, make the most of it!
Hereās a chemical spray that I use:
Pyrethrin or pyrethrum (PyGanic, Pyrenone) is produced in the flowers of Chrysanthemum cinerariaefolium and is the forerunner of the synthetic pyrethroid insecticides. It is available as an emulsifiable concentrate, (PyGanic), or synergized by piperonyl butoxide (Pyrenone). Pyrethrin is labeled against a large number of pests. It may be moderately to highly effective against leafhoppers, aphids, pear psylla, apple maggot, codling moth, true bugs, caterpillars, mealybugs, plum curculio, and thrips. It is quickly broken down in the environment and may be used up to and including the day of harvest. Pyrethrin is relatively non-toxic to humans and other mammals, although the dust produces allergy attacks in people who are allergic to ragweed pollen. The acute oral LD50 is 1200 to 1500 mg/kg. It is toxic to fish, and has a low bee-poisoning hazard.
PyGanic Gardening is a flexible, broad-spectrum insecticide that is organically compliant. It contains the organic active ingredient, Pyrethrins, which is derived from chrysanthemum flowers. Use PyGanic Gardening on growing crops and ornamentals in a outdoor garden setting. PyGanic Gardening provides rapid knockdown and kill on over 100 different listed pests. This product is OMRI listed for organic use. One pint makes up to 16 gallons.
Contrary to Cooleyās assertion, Pyganic is not listed for use against curculio, but I imagine it works. Itās quick. It has to be because it does not persist in sunlight. I pick the first warm evening after petal fall and nuke all that are abroad in one night. Pollinator exposure is minimal as is the risk of rain following.
There are differences of opinion, of course, about needing to use a persistent insecticide on curculio:
BTW, it is officially too late to prune apples in Sheboygan, WI, as I finished doing that yesterday.
I spray surround starting at shuck split and then every 10 days at least until they start disappearing in heat of summer. Where I am itās rare to not rain at least once every 2 weeks (usually more) in the spring so need to spray after every heavy rain. Pretty effective. Pome fruits are more forgiving than stone fruits due their thicker skin. Can always thin the stone fruits with pc damage.
I used organza bags the first year but itās very tedious unless you have very small number of fruit. Also if you have poor leaf coverage the bags act as mini greenhouses and you can get sun scald on fruits like apple.
Inorganic measures are going to be easier and more forgiving than surround, especially if you go away part of the season
I found the OMRI -approved spray Spinosad fairly effective, followed by bagging with trimmed ziplocks after the June drop. Now plastic has a bad rap, so I may have to change tactics. The bags work well when you are going to be away from home for long stretches, so canāt spray. The Surround didnāt work as well for me and bothered my lungs when I then tried to bag. I bagged well over a thousand apples last June, and friends also bagged several trees.
I spray for PC and in my experience it is 99% a matter of timing. They will go from not active yet to wiping out a few of my trees in 24 hours and if Iām not paying attention I can lose a LOT of my orchard to PC. Once it gets close to them appearing I try to inspect for damage once a day and the first time I see a strike I start my first spray. I have also learned to keep spraying (following the directed intervals on what your using) until PC season is over. A couple years Iāve stopped before PC season has ended and Iāve regretted it
Good luck!
Surround is fantastic. It does need a bit more maintenance since the PC are not outright killed but to avoid pesticides its worthwhile for me.
What product have you found to be the most effective against PC?
Information Iāve collected regarding PC in NY.
Spray at apple petal fall and continue at 7-10 day intervals. Hereās link that may help
Imidan - 5 stars
Actara - 4 stars
Avaunt)- 4 stars
Sevin (zeta cypermethrin)- 4 stars
Triazicide (gamma cyhalothrin)- 2-4 stars
PC usually do not feed or oviposit when nighttime temperatures are below 50Ā°F. If the weather is extremely warm after petal fall, the oviposition cycle may be completed in 2 weeks. In cooler seasons, PC may continue to oviposit for 4-6 weeks.
I alternate between Sevin and Eight
Avaunt is good if you spray at petal fall or shuck split. Itās not as effective later.
The other extension office one town over has warned me pc is the worst around here. Right now my plan is to manage with surround and they said it should work but id not message them back for next year lol
Not Six sevin? 
Use this link for my method of controlling PC.
I found this useful when I was looking into spray schedules.
Great document.
My kids want to upvote your comment. Iām still looking for the downvoteā¦
Spinosad is what I use, and Iāve been pretty successful over the last couple years depending on it plus Surround.
I have tried using surround on my peaches the past 3ish year and it never worked for me. They seemed to find the fruitlets no problem and didnāt care that the fruit was coated and would bite right through it. Plus it was a lot of work to spray. Other people seem to do well with it though and edible landscaping whoās near me does it successfully every year and there fruit come out beautiful. Maybe Iāll try once more this year? I have also picked up all fallen fruit before the larvae entered the ground. Sadly it didnāt work either. They are persistent little buggers.
I introduced ducks into my orchard this year to help with Japanese beetles but hoping they will also eat plum curculio.
Thanks for all the input
What a wealth of information. Having only sprayed neem oil off and on over the years, itās now time to step it up. We lost an old redhaven peach this year to bad location that led to high stress, disease, and bugs. After pruning stone fruit yesterday the younger peaches, nectarine, apricots show similar damage from disease albeit in a better location. The disease and pc damage seem to be the most obvious targets to pursue. Surround showed up yesterday, still shopping for spinosad, backpack sprayer parts to arrive Wednesday and new pump for Northstar spray tank on Tuesday.
Looking forward to a productive growing season