Peach trees and my losing battle with OFM

Good day

First time posting here. First I must say peach trees grow so fast and you can see results of your work so quickly. The first growing season we bought 3 trees 2-3 ft tall Red Havens from our local grocery store. The sticks were about 1/2 inch dia. Read up on open center shaping and the fun began.

First year, I recall spraying just once and even managed to get 2 nice large peaches! The trees really built nice scaffolds

Second season. After a good pruning to keep the open center, the trees were covered in blossoms. Due to rain and business travel I missed spraying until well after shuck, maybe 3/8 inch dia fruit. But by then the clear oozing was well in progress. slowly every fruit drop over a one month window. S sad…Dang those OFM

Third season, this year. The trees were 9 ft tall/wide with 3 inch dia trunks!, sprayed with horticulture oil early spring,The open center still maintained after pruning. The blossoms were quite thin, max 30-40 on one of the trees. The two other just 10 to 20 blossoms. I’ll take what I can. I looked at the blossoms daily so once the petal fall occurred, I could spray. This is where I think I failed. Peaches have a sturdy bud cover, not sure the actual name, but in any case they look like there are petals. but looking closer, I could see tiny fruit, so I sprayed. Sprayed again at shuck, maybe 10 to 14 days later. By the time the peaches were grape size many of them show the darn clear oozing.

I use the Bonide Fruit Tree Spray, with Malathion and Captan. So what is my issue/s; Missed a accurate petal fall by a few days?? Bonide not the best defense against OFM?? Should I have sprayed at bud pink??

Any help for “next year”, would be appreciated…

Patrick T

I was spraying triazicide every 3 weeks last year and felt like I was losing the battle (and killing all of the local pollinators). I was ready to try something new, and I am trying the bug zapper/lure for OFM: Moth Pests & Spray - #6 by CRhode

I have only been doing it for about a week, but I feel it has made a huge difference already. I had a few hits before starting, but none since. I am also using a lure for grape berry moth since I have had a problem in the past with them. Another benefit that is that rain does not impact what you have to do- since it has been raining every day my surround is largely washed off leaving me with no other protection.

Hi Patrick, if every single peach drops that usually means your problem is plum curculio (PC) not OFM. The PC eats the seed which causes the fruit to drop. OFM usually start out in the shoot tips and not in the fruits, at least in my climate, and it is mainly in bigger fruits that there is OFM damage.

I would suggest picking up a dropped fruit and getting the worm out. If it has “legs” (doesn’t just flop about in your hand) its an OFM, but if it seems to be just a roly-poly thing its a PC worm.

You also should pick up all the drops as those contain the next generation’s pests. Maybe its too late now but I would guess it is not.

I’m not sure why your spray program is not working but it could be that you need to do more than just one spray. I use Surround so am not familiar with synthetic control programs… maybe @alan or someone else using a similar product be able to help out.


Try Spectracide Triazicide Once and Done- the formula labeled for fruit trees.

Malathion has a very short window of protection- you’d need to do a lot of sprays to protect from plum curculio, even though you probably only get one generation in your zone.

Check guides and you can read what I do and recommend in S. NY.


As mentioned, malathion is pretty short lived. Also, it’s somewhat to breakdown in alkaline water (called alkaline hydrolysis). If the spray solution sat for very long, it can lose potency.

With a severe PC problem, as you describe, you’ll want to spray the first spray at petal fall, then again at shuck split.

I spray once a week in the early season to control PC. We have heavy PC pressure here (KS/MO), as well as lots of rain. Even spraying weekly I get some PC scars.

Triazicide or Permethrin would be a better choice than malathion.


What a great site, thanks for all the input. I’ll cut a falle peach today and try to ID the critter. I’ll also go to Guides and read up.

1 Like

I cut one of the fallen fruits and removed the worm. It’s 3/8 in long, pinkish white with a brown head. It crawled 3/4 in while looking at under a magnifying glass.

Legs are hard to see but I’ll look at it closer once it has expired after a slash of rubbing alcohol.

I did not mention but there has been very little flagging, one or two branch tips per tree. This was noticed after the clear ooz was first seen.

I saw in the guide some sprays have a short shelf life. We mix a fresh batch each time but, the bottle of Bonide Fruit tree spray is now 3 years old.Kept in a garage. Could that be contributing?

Scott’s right about picking up all of the drops on a daily basis.
It’s critical in controlling PC, which is what you have. Personally,
malathion works well for me. As Mark stated, spray once at petal
fall and again at shuck split, but those are the only sprays I do.
Each spray program is definitely site specific, so what works for
one, may not work for others. You’ll have to do some experimenting
to see what works for you.
Spraying with horticultural oil doesn’t really do anything.

1 Like

Like rayrose. Im having success this year so far at least, with just two early sprays. Im using permethrin. I sprayed in early march just as rayrose described and have not seen any PC bites since. Thats after losing nearly every single fruit to them for three years in a row with similar signs to what you have described. Not sure if i will have a second generation PC but time will tell. I bagged half the peaches to guard against that.

Where are you in zone 5b? Location can be an indication how much pest pressure you have.

If those worms walk away, they are OFM.

If they roll around because they have no legs, they are likely Plum curculio worms. Also, PC scars have a crescent moon shape, easy to recognize.

Also, I have seen both worms in one fruit. They are vicious.

A lot of us don’t have a lot of faith in Bonide Fruit Tree spray. Bonide has other strong products but I have not use them. Be careful about where you store those chemicals. In a garage in your zone, the chemicals are likely to freeze in the winter and get very warm in the summer. Probably affects their efficacy with such extreme condition.

If you have heavy pest pressure, weekly spray during a peak pest period is a must. I used to have 10-14 day interval, saw a lot of damage during those extra days. PC has about 2 generations in one growing season. OFM is up to 5. I have seen OFM shoot tip damage into late Sept where I am. Could be in Oct but I am tired to check by then.

A fresh batch of Triazicide Once and Done (by Spectracide) like @alan suugest is one of your options. Peaches set tons of fruit, I hope you vpcan some that are not yet damaged. However, if you do not plan to soray this year. Don’t buy the spray yet. Wait till next spring when you need it,


I pulled out a microscope and also googled OFM worm legs. The worm I puled out has tiny red/orange hair like spikes along each segment along the belly. not legs like a classic tomato worm. So still not clear what the worm is.

Some of the peaches also had the crescent shape scaring know of the PC.

This crop is lost, many have fallen in the last few days. And there’s not many left. But that is why I’m here, to figure out what to do for next year. Should I continue to spray to kill the current population of PC and or OFM even if all the fruit is gone?

I’m in Bloomington IN. We did have a long cool wet spring but no cold snaps.

If I were you, I would not spray this year. (personally choice as I avoid spray chemical when I can). You will likely see shoot flagging for a while, cut those out. Sometimes you will find worms inside those shoots. (I cut them in half witn my pruner).

Like @scottfsmith said orchard sanitation is a must. Don’t let dropped fruit lying around and don’t throw those worm-infected fruit in compost pile.

You may want to check U of Indiana extension services re. What else can ruin your peaches and the trees. Where I am, we have tarnished plant bugs, stink bugs and coddling moths, too.

Also, read up on brown rot.
, a serious stone fruit disease. You will get it sooner than you know.

I use bug zapper where I use OFM lure instead of mosquito lure(Oriental Fruit Moth - IT034 – ISCA Technologies). It goes on an hour before sunset and off an hour after sunrise. Comparing to the damage I had without this set up, it helps a lot. The key is to set it early(before apples start to flower ) and set it at least 20 ft away from the trees you protecting. If there are neighboring trees that are infected the zapper should be placed between them and your patch. At least it is how I have it set up.

One thing not often mentioned about controlling OFM when you start to see flagging is that it takes very little pesticide to get things under control because they only attack the growing tips. I can protect probably close to 50 young peach trees in my nursery with only about a gallon of spray aimed only at the tips- the tips whose growth I need.

If I don’t control them with about 3 sprays during the growing season I lose a great deal of positive growth where I want it.

1 Like


last year, I too had some flagging on a few branches I had want to grow out to maintain the open center. Speaking of open center, I should start another thread on peach tree pruning…

@alan how about the fruits? You have to spray them otherwise they will get attacked, right? And fruits will be all over the tree…

How do you know when to start spraying and when to stop?

I’m definitely getting hit by OFM right now (confirmed that it walks). I have Triazicide, should I start spraying that once per week now? Do you spray just the peaches?

Where I am in S. NY OFM hasn’t often attacked fruit as long as trees are entirely sprayed with insecticide at petal fall and 10-14 days later. However, a couple years ago they destroyed my Indian Free peach crop. Hadn’t happened before or since. I didn’t protect that tree’s shoots, however. If I had, maybe they would never have made it to the fruit. I think they start in the shoots.

It’s all a matter of where you are, but the climate is changing.

1 Like

Extension services usually recommend hanging traps to check the pests’ first flight. Then, you know they are coming.

Pest like Plum curculio you should monitor your local temperature, too.
. They will come out in droves when night temp is around 70 F. Cold, damp weather slow their emergence.

You need to keep track of when they first arrive and when they peak. Each area is different. Even the same area with different weather, it gives different results.

The extension services of Cornell and Penn State often have good info.

thats why in haven’t seen PC here. we almost never get a night temp of 70f here. hopefully it stays that way!