And I apologize for the serious lack of references. It's really late and I'm trying to just regurgitate what I can remember.
History: Apparently, sometime in the mid 1800's, this basically harmless beetle found in Colorado decided it was going to start demolishing potato plants. The bug spread fast and was found on the East coast by the late 1870's. Damn evolution.
Life Cycle: Potato bugs overwinter in the soil. They begin the season by digging out (conveniently) right around the time the tomato plants emerge from the soil. They consume immense amounts of plant material, preferring potatoes but also known to nosh on other members of the nightshade family (peppers, eggplants, and tomatoes). We've also found them on thistles, but I didn't look to see if they were eating or not. After eating, they mate and lay clusters of bright orange eggs on the underside of the plant's leaves. These eggs hatch, the babies eat more plant, drop into the soil, and bury themselves in preparation to demolish next year's crop. Good times.
Cultural Control: Basically, you're F'd. Just kidding, there are a few things you can do. You can hand pick. Three times a day (because, especially if you live in an area where potatoes are intensively grown by industrial farms, the suckers can fly in from the fields to your homey little garden). As you're muttering to yourself about whether or not potatoes are worth all this headache, drop the stripped monsters into a jar of soapy water, oil, gasoline, kerosene, or whatever killing liquid you desire. Make sure you check every. single. leaf for eggs. Crush them or pluck the leaf and drop it in the oil. Prepare to do this for the rest of the growing season. Try not to harm yourself while thinking about this.
You could also encourage ladybugs to visit your garden, as they eat the eggs. Unfortunately nothing eats the bugs.
Also unfortunately, companion planting or rotation are of little help here. Nothing bugs these bugs. And they can fly far enough that rotation is useless.
Chemical Control: Furthermore, even conventional pesticides are mostly ineffective on potato bugs. They quickly develop resistance to any pesticide that is regularly used on them. There is one conventional spray on the market (can't remember the name) that is still effective, but only because it's still new.
But fear not, organic growers, for we have some options that actually work... well, they work well enough. Neem oil, so useful at generally killing buggy pests, can be used to kill potato bugs. However, Neem only has a residual affect for 3 days maximum (often less). Another option is Spinosad, which is a concoction of some virus or something (I'm tired, I can't remember) that, when ingested by the bugs, makes them so excited they die. I'm not joking. But it works, it has a residual affect for up to 7 days, the bugs so far haven't shown resistance to it, and it doesn't harm beneficial insects once it's dry. Plus I have noticed a few other side effects. First of all, any bugs that do survive feed slower. And most importantly, the ones that live long enough to lay eggs almost always lay their eggs ON TOP of the leaf, making them easier to spot. Of course I've also found them on blades of grass under the plants, so it still helps to be thorough.
So there you go. But I hope that you found this post because you love my wit and not because you have this problem. Because I wouldn't wish these things on anyone.