By spraying regularly with a broad spectrum poison you have killed off the beneficial insects that could help control the pests. What you have is the larva of one of any number of moths and the single best way to have it identified is at your local UCAL USDA Cooperative Extension Service office. Put one of the wee buggers in a sealable plastic bag and take it in.

It may not even be a caterpillar. Rose slugs are a not so rare event on coleus and if it is a sawfly larvae, Bt is not effective.

Thank you both. I am so new at this, what is Bt?

Honestly and truly, proper identification is important if you intend to apply Bt (Bacillus thuringiensis-kurstaki). Bt will not control these critters if they are sawfly larvae and frankly, by the time you sprayed this method of biological control on your one plant and waited for it to work, you could have hand picked these caterpillars off about a million times, lol!

Hand removal remains the fastest and most effective method of caterpillar control for just one plant....or a small garden.

I thank u all for your help. The first plant infested was already to late to save by the time I saw these pests. They are nocturnal and only on the 3rd day did I look at night, I drowned that plant, bugs and all in a bucket of water and bleach! There were sooooooo many of them. found 2 more on another plant, took in for i.d and they were green web worms, was advised to use Bt. Evidently in my area ( East County of San Diego) there is an infestation of these pests right now.