Yes. They have a voracious appetite. They can devastate a garden in bulk. Best thing to do is pick as many off as you can, and spray your plants with BT(Bacillus thuringiensis) which is the active ingredient in Dipel. I use the Safer(R) Brand personally. It keeps them at bay. Actually causes a plague. Totally safe for humans and pets. Only attacks budworms/pillars/etc.
thats bad, i picked up as many as i could, and still small so surely they werent mature enough to make babies. spraying insecticide i think would be risky as they are 2 weeks into flowering
Well, Im not sure can you got better advice than what you already got here. Read about that Bacillus and order XenTari. You didn't read about advice at all or search for BT. If you dont like OMRI list and approving ,well .... you can alwasy pick an halloween mask and scare caterpillars to death. Thats organic way for sure.
Caterpillars will also cause mold and bud rot because they eat in circles as they travel up the bud eating the little stems off the main and then the little pieces of bud die and rot if they get wet.... Last year I got hit hard and had to spend a few hours a day in the garden picking them out and feeding them to the chickens. I was growing corn nearby and i think that attracted them. Using BT this year and no signs of them.