I have been away from my garden for some time, i just found my tomatillos cover in these. They are on no other plant in my NJ garden. I prefer not to spray edibles , or anything, with chemicals. I will be hand picking them off unless there is a better way.
These are larvae of a leaf beetle, maybe those of the three-lined potato beetle, Lema daturaphila - see http://www.gardenculture.net/troubleshooting/bug-battleswhats-eating-my-tomatillos-2640
