Spraying to kill Oriental Fruit Moth before emergence in the silk cocoon

Maybe be I’m over thinking this but I want to get a jump on the Oriental Fruit moth. The last two years I’ve had 100% destruction. With advice from the many helpers on this site, I have a plan after flower peddle drop.

Can I be more proactive and kill the overwintering larvae while in their cocoons on the tree bark and in the soil duff? One of the chemicals recommended on this site is Triazicide. Reading the label it can be used 4 times before bloom and 5 times after. Also, it is used to treat lawns to kill underground.

Would using Triazicide a month before bloom treating the tree and soil below the tree kill off much of the OFM larvae? Or even as close to bloom as showing pink?


By seeing no replies, I assume it’s a silly question. Insecticides don’t kill eggs?

Its not a silly question at all. I’m sure spraying the bark and ground would kill some larvae. But my guess is the protection of the cocoon plus the very low activity of the insects would make it a lot harder to get a lethal dose to them. If it worked well, growers would all be doing it.

Do you think oil is a better choice at that stage than Triazicide?

I don’t really know, but guessing I would say a poison would work better as the oil doesn’t last long and 100% coverage of a cocoon is not likely - it is probably under a bark flap not directly in line of the spray. Maybe oil plus a poison is a better idea than either individually. Again I doubt it would do a lot, or some grower would have figured this out years ago and spread the word.

1 Like

I don’t think there would be much (probably none) advantage to trying to kill OFM w/ insecticides before the growing season.

One female can lay a couple hundred eggs, so it doesn’t take very many moths to completely ruin your stone fruit anyway.

I’d wait till the season gets going and spray when the fruit needs protecting.

OK, thanks. I’ll save my efforts for good timing at petal fall. Darn those OFM

I believe its best to wait too. OFM are normally sprayed after the eggs hatch. Traps are used to count the insect numbers and the first spray occurs so many degree days after biofix. Computer models are often used to collect weather information and make predictions about the ideal time to spray to kill the first generation and other generations of OFM. Knocking out most of the first generation really helps. Mating disruption lures are available too but I have never tried them.

1 Like


I hear it’s difficult to get a biofix with only 3 trees. But assuming you can get a biofix, don’t you spray at petal drop no matter what? And a follow up 7-10 days later?

Is there a rule of thumb with regards to first generation emerging with x days after bloom? I’m in Southern IN, so maybe Purdue has degree day counter. It would be nice if they had a biofix by county!

I have such heavy OFM pressure, I’ll likely be spraying every week from petal fall. If the first generation hits exactly between sprays, 3.5 to 5 days, before/after a spray, will I miss my chance??

1 Like

A spray at Petal fall is required but in my area it’s focus is mainly for PC and plant bugs but it gets the OFM too. Followed by another spray around shuck split and another a week or two after that followed by a series of cover sprays normally every 14 days

I would not worry about missing the OFM flight by a few days if you are going to be spraying frequently.

Wonder if the chemical you are using is doing the job? If you only have problems with OFM a product directed only at OFM may be useful like CYD-X.

1 Like


Thank you. The spray I was using the last two years was Bonide Fruit tree spray. By recommendation/s here, I will be using the Triazicide. I also read I should use Spinasad.

I looked at CYD-X and it’s for Coding Moth, but the same company has an insecticidal virus for both Coding Moth and OFM, Madex HP. From the directions, 0.5 - 3.0 oz per acre, it looks like a commercial product. I see Scott Smith posted about this Feb 8

I will also focus on timing. I think I waited to long. I waited for nearly all the petals to fall. By then, many of the shucks even split.

1 Like