The use of IGRs have been quite helpful in controlling insects. IGR, or the insect growth regulator, has proven immediate effect on the lingering presence of some of the most pesky insect pests in homes. The question is, is the insect growth regulator effective at preventing growth on flea eggs, larvae or pupae or other insects? Many people also ask if it will kill the insect or how does it really effect each stage of development in the insect.

There are really two types of insect development: complete life cycle or simple metamorphosis. The IGR works a little bit differently in both types of development. If the insect undergoes a complete life cycle, like fleas, an IGR can effect a couple of stages. The important thing is that the IGR must come in contact with either the eggs and the larval stage. A treatment of IGR is strong enough to postpone the eggs from hatching or ultimately, not allowing the pupa to emerge from its case into an adult. Some products that are mixed with IGR, such as Precor, contains methoprene, which can evidently deflate flea eggs indicating that the embryo inside has essentially died.  It is the best to defeat fleas while they are still eggs rather than waiting for them to become adults and causing more infestation in the place.  For animal owners, they can also try using pet care products that contains IGR in them, like Petcor, which also has the active ingredient of methoprene. This way any flea eggs on the pet’s fur will come in contact with the medicine immediately and discontinue its growth as an adult flea. Moreover, if an IGR is applied to an area that the eggs fall, then it will affect them on contact as well.

The reason why an IGR is so effective is because it is actually a “juvenile” hormone, or actually, we should say that it is a synthetic that mimics the hormone. Let’s take fleas, for example. Naturally, there is already a hormone that is found in the larval stage of development. As the larvae develop and grow, less of this hormone can be found in the flea. Less of this hormone means that the adult flea characteristics can develop normally and eventually, the larvae will pupate and emerge into the adult flea stage that is fertile. However, if you can imagine, when an IGR is applied, what we are actually doing is exposing the flea larvae to massive amounts of the synthetic “juvenile” hormone. The abnormal levels of the hormone in the system restricts the larvae from naturally developing the characteristics of a sexually fertile adult flea. So, although the larva will pupate, the will never emerge from the pupa stage.

For adult fleas, there has not been enough evidence to say that the IGR will kill them except for some cases where adult female fleas become sterile or sometimes affecting the eggs inside and discontinuing their cycle to reproduce more fleas.

For other insects that simply undergo simple metamorphosis, IGR is not quite the killing agent but it causes sterility and deformities on the insect. The cockroach, for example, does not undergo a complete life cycle but just undergoes a simple metamorphosis. This means, they don’t enter a pupa stage but simply grow bigger and molt to the next instar. They do not die by coming in contact with IGR, and instead, they will acquire deformities in their body like having wrinkled wings or a corrupted body. The effect of the IGR goes through every stage and causes some damage at every level. Moreover, it causes sterility on the roach when it turns into an adult and thus breaking off the population cycle of the roach.

Basically that is how the IGR has become a very crucial tool for the household and pest control. It’s easy to control pests if you have an IGR stored and ready to use once the pests infest you. It is a necessity to help eliminate those eggs and larvae that are still loitering in the corners of your home.