Can we use extra herbicide for insurance?

"Can you mix Bt and Sevin together to kill horn worms "and squash vine borers?”

And this is from R. D. 

Interesting question. He wants to mix Bt and Sevin together to kill horn worms and vine borers.

Look how Mr.  D is looking.- No. No. No, no, no, no.
- There's no need to do that because in many cases, they will kill the same insect. And if Bt will kill the caterpillar that it's supposed to kill, then don't add Sevin to it. If Bt will not kill the caterpillar that you're trying to kill, then just use the Sevin or another insecticide, because you're wasting your time and energy putting Bt out. So it's a waste of money, just identify what insect you have and what pesticide you need and use it, but no, there's absolutely no reason ever to mix Bt and Sevin, because Sevin will kill the Beneficial’s. There's no reason ever that I know of to mix those two products. No need to mix them.
- No need to mix them, R. D.  Ever, he said! Ever, ever. Alright, here's our next viewer email. And we're picking on Mr.  D today. "If six ounces of a said herbicide is recommended, "what's wrong with using eight to 10 ounces" for insurance sake?”
Love to know what Mr.  D thinks about this. And this is from Mr.  Bob. And so six ounces is recommended. What's wrong with eight or 10 ounces?- You may kill the things that you want to live. If you go above the labeled rate on a herbicide, there are several things that can happen. One, it'll cost you too much money. - [Chris] You're wasting money. - Two, you may have an environmental problem, you may have carryover into next year that creates a problem. And three, you may have vital toxicity, and if you use above the labeled rate on a herbicide that you're spraying over the top of, say, a broad leaf, to kill the grass of the broadleaf, if you go above the labeled rate, you might kill that broad leaf too. Same way with a grass lawn, when you're trying to just kill the broad leaves in there, if you go over the labeled rate with a product that is targeting the broad leafs, you may kill your Bermuda grass. So the label is a legal document that you are bound by law to follow, and I'm bound by law to make no other recommendation outside that label. So when you're using the product, you're responsible for putting it out correctly, you're responsible for where it goes, that means if it goes on your yard, you're fine, if it drifts to your neighbor’s yard, you're responsible.

- [Chris] Runoff.

- Really, really study those labels. Those labels, there's a lot of money that went into creating them, and you need to really, really look at them.

- The label is the law. - The label's the law, that's right. It's a legal document.