Milky spore disease is a bacterium that controls chewing insects, including beetles, and can be purchased under several brand names. Once established in your soil, it lasts up to 20 years as an effective beetle control. Buy it at your local garden center, follow the directions to the letter, and apply in late spring or fall. Watering well for three to four weeks can keep them under control. Or soak the sod with a solution of 1 ounce of dish soap and 2 gallons of water, and cover the grass with a flannel sheet to catch the bugs as they flee.
Experts agree that insecticides and human control have nearly the same efficacy against chinch bugs.
A spongy lawn indicates a thatch problem. Thatch is particularly a problem in lawns previously treated with chemicals where the grass's natural ability to decay has been destroyed. Dry thatch repels water, while wet thatch invites fungal diseases. The best control is raising the lawn soil's pH level. The best time to dethatch is in late spring.