Bt *is* still on the market and it's sold under various brandnames, among them Dipel, Attack for Caterpillars, Safer's Caterpillar Killer, and more.

In order to find that info, you need to read the ingredients list on a label. Look for Bacillus thuringiensis and/or Bt.

But the catch is that you have to apply Bt while the caterpillars are very young so that they get a dose at the first bite.

In other words, you need to repeat spray as needed. Then, too,you must completely coat the leaves/flowers/buds the critters are eating.

Or you can do regular search-and-destroy tours through the garden. Very satisfying to know they are *really* gone!

Seems like we've heard this false rumor regarding Bt before, and also from one of the big box stores. Unfortunately, as much plants and gardening supplies that are sold from these outlets, their gardening staff tends to be woefully ill-informed.

Perhaps because people think that Bt (spelled out or not) is a product name. (Don't know for certain, though.)

I was just about to post a query about these same tiny green worms. Are they caterpillars that will turn into something beneficial or beautiful (like the butterflies that come from the tomato hornworm). I'm willing to sacrifice some of my petunias, if so. But if not, I'll just keep squashing them.

My petunias are all in hanging baskets, so it's easy to keep an eye out for the worms. But I can see how having beds of petunias would make it really hard to control them.

Up front - I am neither against BT or chemical products that fight this pest, take your choice! We have had major problems with this critter here in southcentral KS, USA. I have tried Sevin, BT, even Triazicide and (now prohibited here) Dursban and had these darned things return. I gave up on petunias due to Phytophthora. Last year I had my best control for budworm (as we only have two or three 30" pots of geraniums) when I got down on my hands and knees and slowly, deliberately, went through each plant time after time and plucked/squashed them. It was a PITA, but worth it to me. This season we have had no additional damage - call it luck or elimination in the area - not one budworm.
I believe that budworms are becoming resistant to most insecticides as producers and greenhouses keep trying to prevent them from occurring on their saleable stock. Physical elimination works. If you have a ton of plants, well, keep chemically inducing them...if you have to. Otherwise, change plant varieties.
hortster

johnsaunt, these caterpillars turn into rather plain looking tan colored moths. If beauty is your main criterion for sparing them, then they get the ax. However, the adults are also nectar feeders, which means that they perform duties as pollinators. Some moths and butterflies feed on nothing at all in their brief adult stage. These guys do.

Personally, I'd squish every caterpillar that I could find. They are capable of doing considerable damage. I'd avoid traditional chemical control, however, as there are tiny beneficial wasps that will parasitize the larvae. Use the Bacillus products whenever necessary.

Thanks to all you caring people. Since my original posting my research continues. This site may contain some information you may appreciate. Thanks again for your help!

http://www.osh.com/Cultures/en-US/Articles/GardenNursery/Article-Budworm-2004.htm

I too have been battling these tobacco budworms on my petunias and zonal geraniums. I have tried BT and fertilome which I still am seeing them. I also have seen them on my daphne bush and on my honeysuckle plan. I am at my wits end.

There are some reports that indicate the Tobacco Budworm has developed resistance to Carbaryls so the person you talked with at your Home Depot is giving you bad information at best. The Bacillus thuringiensis - Kurstaki spray or dust is the best means of control, if done early in the life cycle of these pests.
The Carbaryls and organophosphates will also kill off any beneficials you have that could help control the Tobacco Budworm.

BT kurstaki doesn't work as well or not enough. I even add extra tspoon to make it stronger but in a day or 2, worms are back. im just so tired. i have this really beautiful Pillar Geranium and it's so beautiful in the nursery where i bought it from but here at home the flowers just can't take it's flight. worms are attacking them like crazy. i live in orange county, southern california by the way, so summer time is a hightime for worms as they love the warm weather.

It's foolish to make a Bt solution stronger than what the directions call for. And it doesn't work overnight nor on mature caterpillars.

Can electric bug zapper helps kill moth before they start laying eggs on summer time?