While they are not dangerous to people, an infestation of boxelder bugs can be irritating. Once you have them, there aren't many organic options to get rid of them, but there are a couple of ways to prevent getting boxeleder bugs to begin with.
Purge with Sevin Dust
Sevin dust is 100 percent biodegradable, and kills approximately 100 types of insects, including boxelder bugs. Sevin dust is not poisonous to pets, plants or livestock, and can be washed off the surfaces of fruits and vegetables with plain water. Sevin dust is a fine powder, and is generally broadcast by hand, covering the entire area.
An Organic Solution
To repel the boxelder bug, consider planting marigolds around the area. Along fences, space marigolds 4 to 6 inches apart to help repel dozens of bugs, and keep marigold in fertile pots on the patio or deck. It is not exactly an aromatic plant, but the results are a big improvement over using chemicals that may cause harm to the environment.
Another popular method of pest control is to spray Neem oil on surfaces to be protected. It may not be feasible to spray your entire lawn, but you can spray around the house, or along fence lines to minimize the invasion of insects.