An effective pest control management program includes multiple lines of defense. While insect growth regulators, or IGRs, may not show an immediate effect on mosquito populations, when paired with an adulticide, they can be a key component in ongoing pest control. As the adulticide knocks down the existing mosquito population, IGRs keep those mosquitoes from reproducing by rendering them sterile.

“The one thing that people should understand with IGRs is, it’s a slow process, it doesn’t speed up the reduction of pests,” said Jason Everitt, of Rottler Pest Solutions in St. Louis, Mo. “If you understand the biology and how it affects the pest and the stages of a pests life cycle you understand the timing more.”

Once a pest management professional understands that timing, IGRs become an important tool in their arsenal.

Brien Binford of Binford Insect Control in Bryan, Texas, first began using IGRs to break the life cycles of flea populations, but in the last eight to 10 years has used them to control other types of insects as well – including mosquitoes.

“We made the decision to include IGRs due to the added effectiveness and the long-term control of certain insect problems that we have encountered over the years,” he said.

Everitt said he’s been using IGRs since he first entered the pest management business 26 years ago. He first began using an IGR and adulticide combination to control fleas. 

“With fleas the number one process you have to stop is reproduction,” he said. “They lay many, many eggs a day.”

Now, Rottler Pest Solutions uses multiple types of IGRs – heightened synthesis inhibitors and juvenile hormones – as standard pest management practice. Everitt added they’ve found the juvenile inhibitor has been particularly effective on mosquitoes and cockroaches.

“That just knocks out the developmental part of the life cycle and that does very well for us,” he said. “We’re reducing reproductive adults who only make those populations go up.”

Plus, once the mosquito contacts the growth inhibitor, there is opportunity for IGR transfer. “It can give you a bigger area of treatment to neighboring properties,” he said.

Incorporating IGRs into your mosquito control program may nominally increase a PMP’s chemical  expenses, but for Everitt, the cost of adding an IGR to a treatment is more than offset by labor and operational savings.

“You can reduce follow-ups by using a IGR. That’s reducing our payroll cost,” he said. “(It also helps by) reducing maintenance to send a vehicle out there for the follow up.”

And with products that include both an adulticide and an IGR in one, technicians don’t need to worry about mixing products for applications or having different materials available on their truck.

Binford began using a combination adulticide and IGR product about halfway through 2020, and he says he has noticed a reduction in callbacks.

“We are really using it full throttle now and I have been impressed so far and especially in our monthly mosquito treatments,” he said. “We are getting compliments from our customers.”