ChuckT

They used to be quite the plague in Maryland (especially in the early 80's).
I farmed back then, we used the traps with hormone scent around the plants they really tormented (blackberries in particular). Sevin is good for large numbers that are actively eating, it is not particularly toxic to people and pets and biodegrades quickly. For more long term control we used Malathion, but be careful with it as it can be nasty. I saw Orthene mentioned in other posts, it is a useful systemic, lasts a while, but is also highly toxic, be careful and follow instructions to the letter. A long term solution is DOOM, a fungus that attacks the grubs while they're in the lawn. Once applied the stuff lasts forever and eventually will wipe them out locally.