One effective insecticide for chiggers is permethrin. Permethrin works best sprayed onto fabrics and should never be sprayed directly onto skin. This insecticide works via the neurological systems of insects. It should be sprayed outside but not near lakes or ponds because it is toxic to fish.
Other effective insecticides beyond permethrin include products with bifenthrin, carbaryl or cyhalothrin. Multiple treatments with these products may be necessary during the height of an infestation, but in most cases a single, thorough application suffices.
Chiggers typically become established in yards and areas with wild overgrowth and brushy or grassy areas. Another effective method of chigger control is trimming overgrown bushes and generally managing vegetation growth.