Many IGRs are labeled «reduced risk» by the Igrs Protection Agency, meaning that they target juvenile harmful insect populations while causing less detrimental effects to beneficial insects. Many beekeepers have reported IGR’s negatively affecting brood and young bees . IGRs are also more compatible with pest management systems that use biological controls. In addition, while insects can become resistant to insecticides, they are less likely to become resistant to IGRs.
As an insect grows it molts, growing a new exoskeleton under its old one and then shedding the old one to allow the new one to swell to a new size and harden. IGRs prevent an insect from reaching maturity by interfering with the molting process. IGRs can also inhibit the other hormone, ecdysone, large peaks of which trigger the insect to molt. Chitin synthesis inhibitors work by preventing the formation of chitin, a carbohydrate needed to form the insect’s exoskeleton. With these inhibitors, an insect grows normally until it molts. The inhibitors prevent the new exoskeleton from forming properly, causing the insect to die. Death may be quick, or take up to several days depending on the insect.