Insect growth regulators, known as IGRs, are chemicals that disrupt the lifecycle of pest eggs and larvae, preventing them from maturing into adulthood. If a pest cannot reach adulthood, it cannot reproduce and prolong an infestation. In short, IGRs are a form of “birth control” for pests which helps keep the populations of unwanted pests under control by preventing current and future infestations.
IGRs are made based on the way insects develop or behave. They target or mimic hormones that control the phases of molting, or the changes from larval to adult forms. There are different types of IGRs; they will target different aspects of the insect’s growth processes, all with the goal to prevent reproductive adults.
Chitin synthesis inhibitors: Chitin is a component of the exoskeleton. If chitin synthesis inhibitors are employed, when an insect molts it cannot form a new exoskeleton, causing the insect to die. It can also interfere with egg development.
Juvenile hormone analogs or mimics: During molting, the influx of the juvenile hormones will prevent the insect from forming into the next life cycle phase, keeping it at a larval stage and preventing the insect from maturing into an adult.
Anti-juvenile hormones: This will block juvenile hormone production, causing young larval stages to molt too soon into a non-functioning adult.
What kind of pests can be controlled with an IGR?
Some of the most common pests targeted by IGR’s include fleas, ticks, ants, roaches, bedbugs, and other stored product pests.
Since IGR’s address only the problem of reproduction but do not actually kill the adult insect, it is always a good idea to use a knockdown-and-kill insecticide along with the IGR for ultimate population control. (Also keep in mind that IGR’s are NOT for direct application to pets, although it may be used on their bedding. To treat flea problems on animals, it’s a good idea to use a flea collar or other product designed specifically for direct pet application.)
Using Insect Growth Regulators
Since IGRs are more selective, it can take a while for you to experience noticeable results with insect population control. Mixing an IGR with an insecticide can give you immediate results with long-lasting control. IGRs are often recommended and used in flea control, where they can be used around the home or in pet treatments and preventatives, since the products are considered safe to use around humans and animals.
While IGRs are essential in flea control, IGRs like Archer and Gentrol can control fruit or drain flies, bed bugs, cockroaches, crickets, ticks, and some flying insect pests.
When is the best time to use an IGR?
The ideal time to treat your home with an IGR to prevent bothersome infestations is right now, before reproduction becomes a problem.
How long do IGR's last after I apply them?
Insect Growth Regulators (IGR's) typically are effective for about 30 days when used for indoor treatments. On the other hand, if you are doing outdoor treatments you need to make sure to purchase an IGR product that is photostable if you are going to be spraying the product in areas of direct sunlight. Photostable IGR's last longer in direct sunlight.
IGR’s can come in a concentrated, spray, bait, and aerosol form for versatile application. IGR concentrates like Precor and Gentrol are meant to be mixed with water and can then be used as crack and crevice, spot, or fogging applications. (When treating for fleas, concentrates applied to carpets, upholstered furniture, and pet sleeping areas, may prevent adult flea emergence for up to 7 months.)
An IGR Aerosol reaches fleas and other pests or larvae hidden in carpets, rugs, drapes, upholstery, pet bedding and floor cracks. Whatever form you are using, always read the product label carefully for ideal application.