IGRs: Targeting the Immature Stages of Darkling Beetles Could Provide Better Control

MGK recently released Tobex, the first darkling beetle product on the market that contains an insect growth regulator (IGR) with the adulticide. Insect growth regulators are chemicals that inhibit the life cycle of the insect and interrupts the insect’s growth into an adult. Insect growth regulators are usually used in conjunction with adulticides to implement control over multiple generations of the target insect.

While IGR is often used as a general term, not all IGRs are created equal. Juvenile hormone (JH) mimics, chitin synthesis inhibitors (CSI), and anti-juvenile hormone agents are all IGRs, but they don’t cause the same effects in immature insects. Tobex contains MGK’s NyGuard (pyriproxyfen) as the IGR which is a JH mimic. To use darkling beetles as an example, instead of molting into pupae, NyGuard keeps mealworms in their larval state. This is important information to remember after an application of Tobex. Darkling beetle larvae will grow to be larger and thicker than they are normally observed, as they are unable to develop into successful pupae. Additionally, when darkling beetles are kept in the soft-bodied larvae stage they will be easier to kill on the second application. By using an insecticide with an IGR to control your darkling beetle problem, you’re getting more than just a kill – you’re getting better control of future generations.