Insect larvae on apple leaves

Some pyrethroids are calmer than others. The consumer-grade Cyfluthrin sold retail under the brand name Bayer Advanced is an example, and specifically why I recommended it. “Baythroid” is a whole different beast “beta-cyfluthrin”. You can’t legally buy it or apply it in California without a CDPR applicator license and site permit, which I have.

I find that a dormant oil application has a discouraging effect on aphids. Which won’t help once you’ve actually got them.

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maybe I’ll to do that next year…

a strong spray of water is usually all it takes (repeated over the course of few days)

Richard, can you explain any substantive difference between cyfluthrin and beta cyfluthrin? Typing from my phone here, so can’t look it up.

I’ve not noticed any major differences in “families” of chemicals in terms of insecticides.

For example Mustang and Mustang Max (cypermethrin and zeta cypermethrin) are basically the same from a practical stand point. For that matter regular old permethrin isn’t much different from Mustang in terms of its broad spectrum control.

Likewise lama cyhalthrin (Warrior ) and gamma cyhalthrin (Proaxis) both provide good commercial control for their emulsifiable concentrates.

I’m sure both chemicals would get the job done, but neither cyfluthrin or sevin are especially effective on GAA based on the chart from Penn State (fair and poor). However, sevin is less toxic to mite and aphid predators.

I’m using the Penn State Tree Fruit Production Guide more and more. Lots of good info on Apples, Peaches, Pears and Cherry in one location.


Off the top of my head I’d say you could probably find that information at

In terms of understanding pesticide modes of action, you might find this document helpful:
IRAC Mode of Action Classification Scheme.pdf (671.0 KB)

Richard, I’m very familiar with modes of action and also with the pesticide action network.

My specific question was how b cyfluthrin differed substantively from cyfluthrin in terms of pest control.

You seemed to indicate the two were very different.

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Then look it up.

Here’s the labels. Notice differences in listed pests:
Bayer Vegetable-Garden-Insect-Spray Label.pdf (1.8 MB)
BAYTHROID XL Label.pdf (1.2 MB)

I’m seriously not trying to be contentious, but I don’t need to look up the mode of action. Pyrethroids are all in the same class, (class 3 I believe, from memory ). From experience PAN generally offers little in terms of our specific questions.

Just trying to understand the basis of your statement. You have my curiosity, and will do some online research tonight.

Did not see apples or pome fruit on the Bayer Vegetable and Garden product. Is is labeled for use on Appes?

Inclusively under “FLOWERS, TREES, SHRUBS, GROUND COVERS” which starts at the bottom of page 5.

The lady bug is back, but I only saw one…attempted the manual removal method and wound up with yellow fingers, but I got a good portion of them off…it’s amazing how they are just in this one tree…



I really wanted an answer to some of these questions, so I did some online research last night and called Bayer this morning.

First, Bayer said the Vegetable and Garden spray is not labeled for fruit trees. Only ornamental trees.

Secondly, beta cyfluthrin and cyfluthrin are essentially the same thing. They are so close the names are sometimes used interchangeably

Here is a link from Davis which lists beta cyfluthrin as a synonym for cyfluthrin.

Additionally, here is a label for Bayer’s Tempo (agricultural concentrate) which lists beta cyfluthrin as the active ingredient. The consumer grade labels for Tempo list cyfluthrin as the active ingredient.,P8_RINUM:36155,72155-39

From what I gathered on the internet, the only difference between cyfluthrin and b cyfluthrin is that the active isomers are more concentrated in the b cyfluthrin. In other words, the b cyfluthrin has more “active ingredient.”

“the review reports on cyfluthrin and beta-cyfluthrin (the active isomer of cyfluthrin)”

I ran across another source which indicated the same.

“Beta-cyfluthrin is an enriched isomeric form of the two biologically active diastereoisomeric pairs of isomers of cyfluthrin.”

I wanted to make sure, so I called a friend who used to work for Bayer Crop Science. He retired from Bayer and has a long list of credentials in developing their pesticides (He wasn’t simply a salesman for Bayer, but worked specifically in research. He was the lead on a team of Bayer chemists.)

He was immediately familiar w/ the compound and said b cyfluthrin and cyfluthrin were essentially the same thing. I asked specifically if they would control the same pests. He said they would. I asked why the b cyfluthrin (concentrated active isomer) came later, and he said he couldn’t remember the details for sure, but he thought it had something to do with patents, but the compounds were essentially the same. Same efficacy, same mammalian safety profile. He said it was a very safe compound, btw.

Labels of a consumer grade compounds are sometimes more restrictive (and less detailed) than their commercial counterpart w/ the same active ingredient, so sometimes comparing a consumer grade label to a commercial label may seem confusing. Consumer labels are simpler by design because most consumers don’t want to flip through pages and pages of labeling. They just want to know how much chemical to put in their pump up sprayer, or would even prefer not to mix it, which probably accounts for the increasing popularity of Ready to Use (RTU) products.

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I guess you didn’t read the label.

Exactly. That’s why it’s a restricted use product. It’s a whole different beast.

Wasn’t intending to start a huge debate on the efficacy of one product over another or the labelling of pesticides…All I wanted to know was what was on my apple leaves. I believe that question has been answered along with suitable options for treating the problem. Thanks.

“I guess you didn’t read the label”

I did. Nothing there to suggest it’s labeled for fruit trees., which is why I called Bayer.

In terms of the other discussion, I apologize for not understanding your thought process. I had no idea you viewed synonymous compounds as completely different beasts based on concentrate percentage.

Based on pests covered and required licenses to purchase and use. Let’s suppose we spray a cherry tree for aphids. For Cyfluthrin the dosage is 1 Tablespoon per gallon, REI and PHI both zero. For Baythroid the dosage is about 1 drop per gallon with REI 12 hours and PHI 7 days. Baythroid is not labeled for control of aphids on apple trees.The Cyfluthrin will cost you about $16/quart and the Baythoid about $400 per gallon – if you have the license.

Yes, the concentrate of restricted use pesticides are more concentrated. Thus are more expensive per gallon of concentrate, require less concentrate per gallon of finished spray solution, and have more severe signal words. That’s why they are restricted use.

Suppose we put a tablespoon of Cyfluthrin in a gallon of water and then in another gallon of water add the appropriate amount of beta-Cyfluthrin (about 1.2ml) to achieve the same ppm. The Cyfluthrin mixture has zero REI and PHI but the beta-Cyfluthrin has 12h and 7d. Further the Cyfluthrin mixture will not control any of the quarantine pests on my fruit trees while the beta-Cyfluthrin mixture will control 2 of them plus some other infrequent but nasty critters. The two chemicals might be homonyms to you but they are physically different in significant ways.