Plum Curculio

wet just get the apple pests here, right?

Lots of apple pests… Cherry fruit flies are bad here as well. Plum and peach pests are less of a problem, probably owing to the difficulty of keeping them alive long enough to get neglected, “go feral” and host a steady population of insects (like apples and cherries do around here). I have experienced oriental fruit moth on peaches and apricots here, just not to the extent of the apple pests.

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Last year I planted a few plum trees in my backyard and I was so excited to see small plums on one of my tree this spring but most of them had small brown spots. Now I realized that it is PC and I am not going to enjoy my plums this year. :frowning: I have a fig tree for years, never sprayed anything and get fruits every year. No pests.
Guys, how do you fight against PC? What do you spray? I thought, I keep my garden chemicals free but not sure now. Any advice is most appreciated.


Imidan and Avaunt are two of the most potent for fighting PC but they are not sold at Home Depot, Lowes, etc… Triazicide, Malathion and Seven are sold over the counter but only seem to work moderately against PC. If you only have a few trees, Surround can be used. It is a protective clay, not a chemical pesticide. It’s organic and non toxic. The downside is that it has to be diligently applied, and washes away after a certain amount of rain. Also, it can be messy to mix. For only a few trees, though, it is reasonable. @scottfsmith seems to do really well using it even in a high pressure area. Bagging individual fruits is also an option. There are a few discussions in this forum that you can search for regarding that. Good luck.


Permethrin nukes 'em. Not quite but it is the best you will find over the counter. : Hi-Yield Indoor And Outdoor Broad Use Insecticide Insect Killer : Pest Controlling Insects : Patio, Lawn & Garden
Not all permethrin is labeled for use on fruit trees, Hi Yield is. Use the 10% permithrin version, not 38%.

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Thanks, guys. I still cannot accept the idea of using chemicals on my trees. I will definitely try Surround as it’s not toxic and see what happens next year.
When should I spray it? How often? How many percentage of Surround mix with water?
I grew up in Europe and my parents had a huge garden of fruit trees. Lots of cherry trees, lots of apple trees, plum trees, gooseberry bushes, red currant and black currant bushes and I am not even going to talk about so many various vegetables and a green house with cucumbers and tomatoes. They grew it all and never used any sprayers - organic or non-organic, on their fruit trees, bushes or veggies. We didn’t need it. No pests (except some Colorado beetles on potatoes, which wasn’t a big problem), no fungi, no diseases. I miss the garden so much.


On the top right corner of the page, you will see a looking glass symbol. That is the search engine. Click on it and put in a key word like “ Surround Spray”.

Threads with Surround spray will show up. You can read them to your heart content. Your questions have been asked and answered many times.


I started this post 5 years ago, on May 5 2018, which was the first day I had plum curculio strikes. This year I had pc strikes in mid-March. I wonder why the extreme difference in dates?

This past winter, except for 1 polar vortex in late Dec, was very warm. Many things woke up earlier than usual.

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I wanted to try Actara against this year, but couldn’t afford it.
So I am alternating sprays of permethrin and malathion.
Correct me if I am wrong, but as contact pesticides, these sprays have to be sprayed on the PC to kill it, right? Once a contact pesticide dries on the tree and fruit, the PC will not die if they show up later and start walking around and laying eggs?

Look at this post where there is a long collection of hints on using Surround (somewhere in the middle, look for “general Surround spraying tips”):

It is not so easy to use but with practice you can get the hang of it.


Triazicide at maximum recommend strength + NuFilm sprayed every 10-14 days has worked well for me this year. Reapply a few days sooner if there is a lot of rain followed by a warm and sunny period.

Do your first spray shortly after petal fall and then repeat until 21 days before estimated harvest date. Or whatever the PHI is.

Also wait to thin fruit until there is some “June drop” and then selectively thin the fruits that have bite marks.

That’s my strategy so far and the only thing that worked. My plan is to dial back until I’m using the minimum effective dose and then try to switch over to more organic options.


I am working a similar plan. I don’t use Nufilm perse but a Pinene type that I believe is meant to be similar (Pls help me with mix ratios for Pinene II (Nu Film sticker)). We’ll see how it does. Currently, the apples have a good number of PC scars, the peaches not as many.

That Imidan is really effective. No doubt. Even takes care of inside damage - post bite. I think I only used it once . . . perhaps twice . . . last year - and we had so much beautiful fruit.

But - it is soooo stinky. And the powder so fine. It just screams “Dangerous”. Some others mention Avaunt. ? I don’t have to worry about any protection of fruit (too much) this year . . . cause there isn’t much! But, I wish there was another effective alternative to Imidan.


I’ve been hoping someone would respond to this with perhaps some research links. At least one contact insecticide (not for use on edibles though) I’m aware of is supposed to kill them if they simply walk through it, Fipronil. It’s marketed as a defense against termites, I use it against yellowjackets. Spray an active in-ground nest with a very tiny amount of it and they’re done. Soak some hydrogel with drippings from some raw chicken, again with a tiny amount of Fipronil mixed in, let the foragers find it and take a piece of the hydrogel back to the nest. But anyway, you were asking about efficacy of the various contact insecticides commonly used against PC. I too would like to know if they kill only if sprayed directly on, or if the PC walks through or perhaps bites a fruit coated with it. Or lays eggs in I suppose… Will that kill them or does the contact have to be more direct?


You asking a lot. Even when researched there are so many variable you can’t simply answer the question.



What @KSprairie bolded above was the question I was repeating. More of a general clarification of what the word “contact” typically means. I believe that for most it literally means just that, an insect walking through and coming into “contact” with will be controlled. Words in the article you shared like “half-life” and “residual” and “persist” would seem to concur with that. Unless they’re mainly referring to insecticides which require ingestion, Btk and Spinosad being ones I believe that to be true for? Nonetheless, it just seemed like a question worthy of a clear-cut and simple answer, to help folks who will search and find this discussion later.

That’s also assuming that PC is affected by “contact” the same as other susceptible insects. A pest I’ve never observed in any of my trees but I’ve sure seen the after effects of!


Good questions.

Depending on who you talk to, insecticides can be divided into three categories (non-systemic, systemic and translaminar) Systemic insecticides travel throughout the plant, generally from root uptake. Translaminar means locally systemic. That is, it travels short distances. If some of the leaf is covered with a translaminar insecticide, the insecticide will travel throughout the whole leaf. Non-systemic is just on the surface of the leaf or fruit. It does not penetrate at all.

Non-systemic insecticides can either be contact or require ingestion (as in Avaunt, which mostly requires ingestion). Contact insecticides can kill an insect by either being directly sprayed on the insect, or sprayed on the foliage/fruit and have the insect walk on the foliage/fruit. Contact insecticides are designed to be absorbed through the cuticle of the insect.

There has been a lot of research done on half lives of insecticides, and how much wash off, when it re-apply, etc. All this is based on the idea to keep enough residue on the foliage or fruit to kill the target insect pest. Whether it be an ingestible insecticide, or a contact insecticide. As an aside, most contact insecticides will also kill if ingested by the insect, so there is overlap there. The key is that contact insecticides mainly kill by coming in contact with insect.

Systemic and translaminar insecticides generally kill by ingestion. They are in the plant or leaf tissues, and kill when the insect starts feeding on the leaves or plant tissues. Imidacloprid is an example of a systemic insecticide, which is easily taken up by the roots.

However, again there is a lot of overlap. For example many systemic and translaminar insecticides also can kill on contact, if there is enough residue on the surface of the leaves/fruit. But mainly they are designed to kill by ingestion.

Actara is an example of a translaminar insecticide, which can also have systemic activity. It’s translaminar if sprayed on the foliage. But if it’s in the soil, it can also be taken up by the roots and move throughout the plant systemically.

Fipronil is a systemic. It can kill by contact or ingestion, but I don’t believe it is labeled for fruits.

In terms of PC, it’s a pretty tough beetle and not super easy to kill. Actara has worked pretty well for me. We still get some scars, but because of it’s translaminar activity, it has curative ability. That is, it will penetrate the fruitlets and kill the PC larva.

Imidan works very well. It is a non-systemic, but still has some curative activity. That’s because it is so extremely lethal to PC, and is sprayed on much heavier (pounds per acre). Evidently, even if a very small amount leaks into the PC scar, it will kill the larva.

Avaunt is another insecticide commonly used for PC. It requires mostly ingestion.

My own experience is mostly with Actara. It has been listed as one of the most effective insecticides for PC.

We still have some scars using just Actara, so the last few years we’ve generally added a pyrethroid along with it. This results in no scars and also controls stinkbug as well.


Did you mean Imidan?


@Olpea In your post above you put Indar a fungicide. As Danzeb mentioned above maybe you meant Imidan or another insecticide?

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