Does anything stop plum curculio?

General Fruit Growing
#1

Hello everyone,
Over the past few years, I have tried just about every spray available for backyard consumers and even tried to bag my fruits. But no matter what I spray I always seem to get extreme damage from the curculio. I can never harvest a single peach and I maybe got 10 plums combined last year off 5 mature trees. Sprays I have used contain Captan, Malathion, and Carbaryl. Also I used an orchard spray containing sulfur and pyrethrin. Nothing seems to work, and I have applied them according to the bottle, sprayed with a battery powered sprayer and to the point they drip off the fruit. The spray goes on evenly from what I can tell but I will see the little crescent bites the very next day after spraying. When I bagged the fruit the curculio just bit through the bags. I tried the footies and the organza type bags. The organza bags worked for the small amount I did harvest but most of the organza bagged fruit was also bitten. Not sure at this point if it is worth keeping the plum trees or peaches. Also, the plum curculio bit my apples and pears just not at the amount of what they do for the plums and peaches. One pear that was close to a plum tree did get every piece of fruit bit though, so I am not sure if that is a proximity thing or if some varieties of pears are more appealing to the bug than others. Does anyone know of a spray or method that works? I feel so defeated by these little bugs year after year and I do not know what I should attempt for next year.
Any help is greatly appreciated,
Matthew

P.S. I should mention I do clean up the bitten fruit that falls to the ground and I do try the shaking the trees method, but I maybe find one or two bugs.

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Wormy peaches
7a-8b The Carolinas, southern Virginia and northern Georgia/AL/MS
#2

Matthew,
A few questions:
When did you start your spray and how often? Timing is everything.

When you said your use those chemical, were they ready mix in one bottle like a Bonide Fruit Tree spray or you spray each chemical separately?

Have you heard of Clemson peach bags? If you bag clean fruit, nothing get through Clemson bags. I have used all kinds of bags and know that organza bags do not work but Clemson bags do.

This is a long thread about bags and bagging, you can just scroll down to see pics of Clemson bags.

Re- evaluating bagging fruit.

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#3

I don’t think those are the best sprays for curculio. Captan and sulphur don’t help at all as they are for diseases, pyrethrin is very weak and only kills aphids etc. Carbaryl also is not effective. Malathion seems to work for some people but not all from the limited bits I have heard. So of all those things you have only one iffy spray chemical for the curc.

I use Surround myself. I think permethrin is also a popular spray some people use here. Hopefully some other people will pipe up with what they are using - I only use non-toxic sprays and am not as familiar with the poisons.

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#4

Malathion does work but if you don’t acidify the water it’s useless. I think at a pH of 7 it works for 30 minutes. At a pH of 5 it works for 30 hours. I used Bonides Eight this year and it worked well. I also used malathion. Both in acidic water although I don’t know if it extends half life of the active ingredient in “Eight” or not? Pressure was almost nonexistent this year. I saw few strikes.
For organic Surround works if you can maintain protection.
I started a second orchard at my cottage. I wanted a natural no spray orchard. I have a mulberry( Oscar), jujubes, a Shipova, serviceberry ( honeywood), hazelnuts and hickory.
Only nets are needed. I can’t maintain two spray schedules. Persimmons is another that could be added. Anyway alternatives to the more needy fruits.

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#5

Imidan and/or Avaunt. If you want to go organic then use surround

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#6

I haven’t found Surround to be that great, either, but can’t bring myself to using poisons if I can help it. One thing about Surround is you can see it, so know when it got rinsed off by rain.

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#7

I’ve found surround reasonably effective, but you need it out there early and you will take some hits.

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#8

I’ve had good success so far with Sevin. The new formulation of zeta-cypermethrin. It’s long lasting and knocks everything down best I can tell. I alternate with malathion every week during peak times. Make sure you are spraying malathion after sunset and with low ph water as it is both uv sensitive and ph sensitive.

I do have pretty low PC pressure this year but hardly lost any fruit.

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#9

Imidan used with a sticker and acidic water (ph 5) works when sprayed at the right time. Spray 2 or 3 times at 7 to 10 day intervals. If Imidan is not available try Triazicide with a sticker and acidic water instead and spray at 5 to 7 day intervals.
There is a very long discussion here: Plum Curculio

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#10

Surround is an insect deterrent, not an insecticide, so as you say, it is not 100% effective, and of course, unlike some of the stronger insecticides has no “kickback” against eggs that have already been deposited. One consequence of that is that, as others have said, consistent coverage is a must. And getting that coverage before most of the curculio arrive is important. Although, I have no scientific proof of the hypothesis, I’m pretty sure from experience that it’s far easier to keep a migrating adult curculio moving, than to drive one out a tree they have already settled in. It’s also helpful if they have something to move to. To that end, I have generally left parts of some of my larger apple trees uncovered - that’s easy, because it’s hard to get good coverage above 10’ with my spray rig anyway. I know the importance of this, because the only times I’ve ever had problems with curculios in cherries, is when I diligently and perfectly protected all the apples and plums.

I live in an area that generally has very strong curculio pressure, due to a large, well distributed, wild plum and crabapple presence, and lots of woodland for overwintering the curculio. I feel @MatthewInVA’s pain. I’m not sure I could control curculio here with Surround if I had only a few trees. I always get better deterrence in the center of my orchard than on the South edge, where the curculio first arrive, and as I said, need to sacrifice some bearing capacity for it to work effectively.

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#11

Thanks, mamuang for your questions and suggestions. I started to spray them right after shuck split and sprayed again about two weeks later as I started to notice more damage from the curculio.
The spray I used was Bonide fruit tree spray which had all of the chemicals listed combined with the exception of the sulfur and pyrethrin. The sulfur, pyrethrin were part of a combination spray by Bonide as well, the Bonide orchard spray.

I have not heard of the Clemson peach bags, are they difficult to put on and do they last?

Thanks again for your reply,

Matthew

#12

Scottfsmit, thank you for the info on the chemicals. I tried to not use any of the toxic sprays as well but I had no luck. At this point I have had no luck with the toxic chemicals either. I put in so much money and effort in on these trees yet I feel like I have failed at this point. I am not getting a much of a return on the investment of the trees. I do enjoy the process of watching them grow and appreciate the gardening efforts so I do have some return but I would like to get some fruit as well. What is difficult is paying the money for the bags and sprays and taking the time to do all of that and then seeing hundreds of little crescent bites day after day and seeing yet another year lost. I feel a bit heartbroken by it which might sound nuts but I do.
Does the Surround work well from your experience or do you use other methods with the Surround?

Thanks again,

Matthew

#13

Drew,

I have not used the Bonide eight and I did not check my pH before I used my other spray. What would I use to acidify the water? The spray smelled awful and coated everything and even caused some fruit burn so I figured the application was good and thick but still it failed to stop these bugs.

I do have persimmons and jujube as well that I do not need to spray and I’m almost to the point of saying I will just grow these from now.

Do you suggest I should use the eight and surround next year or something else? Should I check my water pH before I spray?

Thanks,

Matthew

#14

PA_Fruit_Grower

Thanks for the reply and suggestions. I used Sevin one year but all the fruit dropped off. I thought the fruit drop was because of the Sevin so I never tried it again. Maybe I will consider it again as I have always had luck with Sevin on my squash plants.

Thanks again

Matthew

#15

walnutclose,

Thank you for your experience with Surround, I do not think I could effectively control the curculio here with it. I am not sure where they all come from but they hit my backyard with a strong power and it really is such a horrible feeling seeing hundreds of fruit become useless. This is yet another year lost and they actually hit my apples and pears fairly hard this year as well. These bugs almost make me want to give up on growing fruit trees.

Matthew

#16

You may want to move up your first spray to petal fall. The plum curculio in your area may be moving into trees earlier than you think. You also could use this free model from Cornell to better estimate when plum curculio become active. The user can select a local weather station as the data source from within the model to better follow plum curculio activity.

http://newa.cornell.edu/index.php?page=weather-station-details&WeatherStation=kshb&WSDetail=http://newa.nrcc.cornell.edu/newaModel/apple_cm/WI/kshb

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#17

Matthew,
I can sympathize with you regarding your thought about wanting to give up growing fruit trees. A lot of us in high pest and disease pressure areas have that thought once in a while.

This thought is more pronounced when we grow “high maintenance” fruit trees like stone fruit, peaches, nectarines, cherries, plums, etc.

There are more than plum curculio but since you need help with this # 1 pest, we will only focus on it.

I think you may have seen Scott’s Low Impact spray program.
Low-Impact Spray Schedule (2019 Edition).

It is not just Surround. Scott has used several approaches to make his low impact spray works for him. I mixed Spinosad and/or BT with Surround to fight against OFM, another serious peach enemy. Surround alone can help esp if you start early and reapply when needed. @mroot said, it could be that your area is very high PC pressure you need to move up your first spray to petal fall.

Like someone said, the chemical I see people here use that appears work with very well is Imidan (from very clean fruit they show). Imidan is not supposed to be sprayed in residential areas so that disqualify a lot of us living in urban areas. Also, as of this year, with new definition, shipping Imidan is a lot harder. Places like Keystone Solution does not ship it anymore
https://www.keystonepestsolutions.com/imidan-insecticide-70-w-5-pounds-399

The others chemical that gain more popularity among backyard growers is the new Sevin with zeta-cypermetrin as the main ingredient. The old stand by is Triazicide (Gamma-cyhalothrin). You are right that the old Sevin (with cabaryl as the main ingredient) has fruit thinning effect.

Other chemicals with brand names like Avaunt, Actara, Delegate. I was told are effective against PC. Those are a commercial grade and may come with some restrictions when using any of them.

Besides what to use, when to use it is as important. Some people can use these chemicals effective and need only 2-4 spray to get the pests and diseases under control.

@alan wrote about his synthetic spray schedule.

.

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#18

I echo the suggestion to use the new formula Sevin, which has been very successful for me. Before using Sevin I also tried malathion (but I didn’t know about the water acidification at the time, thanks @Drew51) I think the Sevin formula changed in 2018, and it was a major change, moving from carbaryl to zeta-cypermethrin.

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#19

Thank you again mamuang, I really appreciate the links and all the advise. I think I will try the Sevin and Surround next year. I might switch to sevin for later spraying in the year because the spray I am using now has caused burning of fruit and leaves. Not sure if Sevin protects against OFM but I will look into it.
Thanks to everyone that has chimed in and offered suggestions and links to more information. It is unfortunate that I have lost my stone fruit crop yet again this year but hopefully I will be better prepared for next year. I appreciate all of the help.

Thanks again,

Matthew

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#20

Mathew,
Fortunately I have not had to fight curculio here, but we have some fairly difficult insects to control such as Apple maggot fly and codling moth. Together they completely destroy apples. Surround alone does not really work well, but if you apply it with a surfactant, and lace into the slurry a couple chemical agents such as malathion and Bonide fruit tree spray with carbonyl it pretty effective against most any pests. I suspect cuculio would not survive an encounter. Probably Sevin may just as effective with malathion. The key to using surround is to apply 3 coats on the first spray after petal fall before your fruit is size of a quarter. Give some time for each coating to dry before applying the next. Then after every rainfall or no more than two weeks spray again, always increasing the coating on the fruit. If you do this you will not need to bag any fruit!
At time of harvest you simply give the ripe fruit several soapy water baths and a rinse and it’s ready to consume.
Dennis
Kent, wa

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