Japanese beetles in apple trees

I have just started noticing japanese beetles this last week. I am wondering if my normal spray of Triazicide will kill them, or do I need to switch to something else?

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I have been giving them a shot of Neem oil spray.

None of the suggestions in the [Agitated Mind thread][1] will eliminate the threat immediately, but it does discuss some of the methods being used.

One thing that I don’t think was discussed was what pesticides are appropriate for addressing current invasions.

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I dust some Sevin on my Kaki and American persimmon trees. They died when touching the white powder.


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I have used the neem oil a few more times with good results. If your looking for an alternative that seems to work give the neem oil a try, especially if you plan to consume the fruit the same or next day. My grapes have been hard hit in years past but two sprays and I have not seen any others. It also gives the grapes a little shine. Bill

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The “go to” insecticide is Carbaryl (Sevin), it is the most effective on Japanese Beetles, even moreso than Imidan in that it has near instant knock down power when mixed strongly. Carbaryl does act as a thinner though and on trees already properly thinned could cause some fruit drop. I’ve used it a lot and only during JB season and I have never noticed any fruit drop on apples. It can be phytotoxic when applied under bright sun in high temperatures. I have never had any issue in this regard either. It is overall probably the safest to use of the group and really nothing rivals it’s effectiveness on JB. It is also widely available and not restricted.

Imidan has moderate control of JB in that it is highly toxic to JB, but can take a few days to work. This, I believe, is true of most of the organophosphate group. 10-14 days activity

Pyrethroids like Olpea and Alan use offer excellent control and instant knock down, and supposedly provide a tiny repellent effect. 7-14 days

Neonocotinoids offer control for 2-5 days from contact with surface residues and then a few days more from leaf ingestion from absorption. It seems that this group would be a poor choice, but does offer the benefit of quickly being rain fast.


I think I will give the Sevin a try. Neem oil seems impractical to me since I have 15 apple trees, 4 cherries and a bunch of others. I use a 15 gallon electric sprayer.

Appleseed pretty much nailed it. I do wonder what the results are with neem as far as staying power- I’m not even satisfied with Sevin and mix it with Asana to get 2 weeks protection, but nothing knocks them off the tree like Sevin.

I haven’t noticed any thinning from Sevin as it is hard to thin apples as well connected as they are by summer time but I have had mite outbreaks after its use. I wish there was something that killed the J. beetles without hurting the beneficials besides Imidan. Fortunately, most of the apples I manage on sites with J beets don’t get bothered so I can leave them unsprayed and keep the allies around. The JB’s sure do love Honeycrisp as “everyone” does.

I’ve counted 3 Japanese beetles this year… last year was very low too…Rose Chafers were missing this year also…so weird…not sure what is going on… They both use to be thick in my yard… i don’t even look anymore. I like it…but wonder if they’ll be back or if something is keeping them in check.

They have arrived in Purling NY about 35 miles south of Albany NY.

Saw them (always as couples coupling) on several plum, apricot and cherries.

Threw them a farewell party.



Maybe i just haven’t accumulated enough heat yet…it was very cool and now its been pretty warm (mid 80Fs) the last few days…cool again this week and hot next weekend (90fs)… so i’m sure a few more will come out.

Since I have a large number of roses, the JB’s concentrate on them. My JB season is just about
finished, and spraying is basically a waste of time for me, because they like to get down inside the petals,
where the spray can’t get to them. But every day as I walk through the rose garden, I can spot them inside
the flowers and I just squish them inside the bloom, which they’ve already ruined. I get about 25 per day.
I especially like to get them, when they’re joined up mating. I know those suckers will not lay any eggs
for next year’s swarm. They leave all of my fruit trees alone, except for Flavor Grenade. For some reason,
they love the leaves on that tree. But the tree has so many leaves, the damage is only minor.

They weren’t hardly here either warm, but at the first break in the rain…here they come. For a while there I thought maybe we were going to get lucky this year…so much for that.

This has been a bad JB year for me. I had almost none for many years until last year was sort of bad and this year was bad - some trees had all the upper shoots defoliated. So I finally spread out milky spore today. I have never used it until now.

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Yep…noticed the same thing here. Actually they seem to favor the grapes the most, closely followed by the plums / pluots. They get after the apples too, but not nearly as much. I see them on the pears and I see a bit of their damage, but they largely leave them alone, same with the sour cherries.
Up in the tree tops where most of the tender growth is, and where I can’t spray as well is where they do the bulk of their damage.
I too like to find them “coupling”, they are so preoccupied it is so easy to just grab them, toss them to the ground and apply foot pressure. It’s a good feeling.

I live near Rayrose and haven’t seen any for the last two days, but while they were active there were more than I’ve seen here in the past. They hit the same types of foliage here as yours did, Appleseed. Except mine also loved the upper parts of the sour cherries and surprised me by congregating on strawberries and blackberries and devouring those leaves. They also totally ignored the roses which have always been a favorite nosh in past years.

I prefer crushing them between thumb and index finger. I find it more satisfying than tossing them to the ground because then they have no chance of flying off.

For me the JB’s prefer Sweet cherries over everything else. Followed by apples and pluots. I haven’t seen JB’s on my pears or nectaplum at all.

Triazicide doesn’t do anything. I’ve been smacking them into soapy water and it’s not too bad since my trees are still young.

I have not seen a lot of Japanese beetles in my garden this year. One or two here and there. Last year I had a lot of them. I also had a lot of their grabs in the soil, I dag in the different parts of the garden and always found them a plenty. This was the reason why I applied milky spore this spring. It looks like it may worked, which is surprising. Or it is possible that we did not accumulate enough heat for the mass infestation.

I used Milky Spore two years in a row, and it seemed to work for the next couple of years. But obviously
the bacteria has a finite lifetime, and only reproduces, when it finds grubs on which to feed. Once that
food source disappears, the bacteria breaks down and dies. I don’t know, if this is a proven fact, but it only makes sense.
The problem is that JB’s fly in from other areas and reinfest your garden, and the cycle starts all over again. But if you can control their egg laying ability, you can limit the numbers. I’ve seen swarms of them at Roses Unlimited’s display garden, which is a large commercial rose nursery in Laurens, SC, and they were like the locusts in Africa, and they don’t do anything to them. It’s just a seasonal thing like thrips.
Luckily, for us fruit growers, they only attack the young leaves and leave the fruit alone. Once JB season is over, the tree can refoliate and the damage is gone.

I foolishly just started another thread on JBs when I did not apply due diligence in searching for the topic. I have had four or five years of bad infestations…tens of thousands. Three years ago I spread Milky Spore, but only in my “yard” and obviously not on the surrounding acreage which is sometimes planted with soybeans. This year they started in May and really hit their stride the weekend of June 27th. They particularly love my Red Ace plum and have hit basically every leaf on it. I have sprayed Sevin on all my fruit trees and on my pecan, heartnut and hazelnuts. The hazelnuts are small and vulnerable as are many of my fruit trees. As I say in that other thread, I can treat all my trees with about five gallons, but the pecan and heartnut trees are tall enough to be a challenge, so I ask for suggestions for a sprayer that will shoot at least a 30 foot stream…40 would be better.