Lab is correct. Bt is not a contact pesticide.....did you not read the labels? One must spray the plant (not the insect) lightly, and sit back and wait for a few days. The caterpillar feeds on the sprayed foliage ingesting the bacterium spores. It might take a couple of days for it to get sick and stop eating, but it will. The infected caterpillars don't shrivel up and die.....they stop feeding and slowly starve to death. If your product hasn't been mixed or stored properly, it's possible for the bacterium to be inactive.

I put a pot with a cutting I took in Spring from the swamp rose mallow right next to it while I try to figure out what weeds I have (or other plants in that family) If they do go for it, great. I will still have learned what I have in my yard. Hope this is really rose swamp mallow. The mother plant popped up about 10 years ago in my brush pile. Since it is by now in deep shade and still flowering nicely, I thought I will take some cuttings. This is a look at the poor aquarium plant and the hopefully new food source.

Here are some photos of mine after she made her cocoon, then when she came out. The final picture is of a male for comparison. If your friend is keeping it to watch it make the cocoon and come out later, they can get a plastic "critter cage" with a vented lid from any pet store. Cocoon made inside oak leaves: Whoa! It's a girl and she's huge!!! Male

I am pretty sure that is a inchworm.. He has no legs in the middle.