- Arriphos 40EC and Forgon 40EC contain the active ingredient Dimethoate, an organophosphate insecticide, with an extremely strong fumigation action mechanism, contact, toxic taste, broad-spectrum insecticide, and can eliminate many types of pests such as: Rollerworms. leaves, stem borers, armyworms, yellow flies, stink bugs, onion mosquitoes, mice, whiteflies, armyworms, silkworms, jumping beetles, twig borers, barnacle beetles, mosquito bugs, dung beetles... on many different types of crops.