The dreaded pets are back

We have had a problem the last 5 years or so with ladybugs. These are actually Japanese beatles imported by the government. There is no way to kill them(by poison), they stink and they sting (or bite). They generally swarm in the spring. I did not have a problem with them this past spring and thought they had finally disappeared from around here. I was preparing to leave for worship yesterday afternoon, walked out of the house and was attacked by a swarm of my dreaded pets (as Mike calls them). Got home from worship and had little dead bodies all over the dining room and kitchen. I guess my reprieve is over. I have to clean the window sills in Mom's room, the living room and the kitchen every day. At times, it is a twice a day wiping or vacuuming of the sills. I know that every creature God created has a purpose, just can't figure out what the purpose is from some of his creations, especially these little buggers. We have tried insecticides and called the county agency for suggestions. I don't understand why no spray will affect them but they can swarm into the house, fly around awhile and then leave their little dead bodies all over the place. If you step on them they leave yellow spots that won't come up, so we don't try to kill them that way. They also attack you, literally, and bite leaving welts that itch.
I wish the government would leave the plants and bugs in their native countries (like these things, kudzu, etc.). It has never worked when they bring things over to take care of a problem here and probably never will. Never knew why they imported the kudzu.