I have a few on mine and the plant is very strong and healthy and
so I just brush them off when I spot them and otherwise leave
them be. They are on some other plants as well. I sort of see
a few living things as a good sign that there is not a large
skull and crossbones looming large over my yard ;-),
I don't use insecticides or anything other than some organics,
and planted mine with basil this year. I just have a few, so
if yours is covered you might be more concerned than if there are
just a few here and there - beats the dreaded tomato worm!
: should i be concerned?