What insect is this?
It's the nymph stage of the Fourlined Plant Bug. Here's a link to more information: http://http//www.extension.umn.edu/garden/insects/find/fourlined-plant-bugs/
Will ladybugs eat the nymph and/or adult fourlined plant bug?
No. They have a hard shell. The only natural predators supposedly are big eyed bugs, damsel bugs, pirate bugs, and jumping spiders and you can't buy any of those. You can use insecticidal soap directly on the nymphs, but you need to keep after them; there is no residual effectivness. You can also prune off the affected areas and drown the bugs in soapy water.They only produce one generation per season, so they'll be gone before too long. Unless there's a very large number of them defoliating the plants the damage is not going to kill the plants. In the fall remove all of the dormant plant material from, and around, your affected plants and place it in your trash, or bury it. Don't compost it unless you maintain your compost and know it reaches temperatures that will kill any eggs.