First: don't use Sevin on your tomatoes, from what I've heard. You will be eating the tomatoes, and Sevin is a particularly toxic, harsh chemical. The tomatoes can absorb that stuff and it could get into the tomatoes you eat.

As for the worms, I'm not sure. Armyworms came to mind, but a photo would help ID them more easily. I think some Florida tomato experts might know what you've got...I'm in Tennessee so I am not very familiar with Florida tomato pests.

I'm in west central Florida and had a problem with armyworms just a couple of weeks ago. They look mostly black from a distance but upon looking closely, they have a bit of stripe to them. It happened the same way here -- first just a few leaves started out with holes, then a LOT of leaves, then they started destroying the tomatoes themselves. We were getting a lot of rain at that time, but now we seem to be in another dry spell. I destroyed all the worms I could and sprayed with Garden Safe insect killer, hoping it would be a bit more mild. Between that and (I beleive) the lack of rain, I haven't seen any more worms (knock on wood!). Good luck!

~M

I got a couple yellow-striped armyworms (Spodoptera ornithogalli) last year that ate some holes in the leaves, but didn't do much damage otherwise. Must be more of a problem in Florida, and with species other than S. ornithogalli.

{{gwi:69924}}
One of the two yellow-striped armyworms I found on my tomatoes last year.

Yeah, Sevin is a carcinogen. Don't put it on anything you plan to eat. It's illegal in half of the EU. It's also super broad-spectrum, so it should only be used as a pesticide of last resort. It'll even kill your earthworms.

Rotenone is a little better than Sevin, but it's got it's own problems (it's suspected to be a risk factor for Parkinson's). If you really want a broad spectrum that's not going to poison you, I'd go with neem or pyrethrin. Neem is probably safer for people who aren't pregnant/trying to get pregnant, while pyrethrin is probably safer for people who are.

Even better than a broad spectrum is a narrow spectrum, though. Almost all "worms" you see on your plant leaves will really be caterpillars. And caterpillars can be killed by Bacillus thuringiensis var Kurstaki ("Thuricide"). That's about as targeted, non-persistant, and non-toxic for humans as you can get; it not only doesn't affect mammals -- it doesn't even affect non-Lepidoptera insects. And it has to be ingested, too. The downsides to it are that you need to apply it once every few days, and that it takes a couple days from when the insects ingest it and when they stop feeding.

Re, Garden Safe: that's pyrethrin in canola oil. A much better choice than Sevin.

They might be beet armyworms. I had them last year on one plant. A nightmare. I must have killed nearly 100 befor they grew to full size.

Use tobacco juice. That is old cigars, cigarette butts, old chew etc. soaked in water for a couple of days then filttered through stocking and sparyed daily for a few days at a time.
Best remedy I know of for all kinds of worms.
Good luck and good harvest.
Ari