When it comes to effectively managing a cockroach infestation, rotating the active ingredient pesticide class can be the difference between a satisfied customer and an ongoing issue. According to Martha Carlson, Owner of Maritech Pest Control, taking advantage of each class’s different modes of action can have serious benefits.
“Where one mode may not have worked well, there is another one or two available,” she said.
Rotating chemical classes can also ward off resistance and even help reduce the amount of chemicals necessary to quell a cockroach issue.
David Marshall, CEO of Arizona Pest Squad, LLC., finds rotating classes seasonally is especially important in a region like Arizona, where the need for pest management is consistent year round.
Pest management professionals today are prepared to use anywhere between three and five different classes when controlling a cockroach population.
“A PMP should utilize multiple modes of action in a single cockroach service,” said Shawn Payne, owner of Lakewood Exterminating.
Payne starts his jobs by using neonicotinoids, juvenile hormone mimics and borates.“In addition, modes of action should be rotated every service,” he said.
Payne assesses the effectiveness during each follow up service and generally proceeds with hydramethylon, avermectins, oxadiazine or fipronil if he isn’t seeing the results he expects. In his treatments, Payne has found that neonicitnoids and IGRs work well in tandem, while borate and oxadiazine seem to work best on American roaches – plus in his experience, they haven’t become resistant to borates.
Carlson has a similar strategy.“I may use a synthetic pyrethroid first rather than a neonicitinoid and pyrethrum flushers,” she said. “This is basically when a high level of roaches exist in a facility that will not open that day, or in a vacant apartment or home. I do this when there is no problem with running the roaches out all over the place for a day.”
She will also use inorganics, IGRs, neonicitinoids, and possibly, if roaches are accepting baits, oxadiazines, avermectin, phenylpyrazoles.
She stops to adjust classes when she knows a particular class may have been used in the past and not resulted in adequate control, or when she determines from inspection, insect monitor quotes or from a customer interview that her current combination is not where it needs to be.
Carlson is also careful about which products she uses in tandem.
“I try to keep non-repellents with other non-repellents and baits. I try to keep synthetic pyrethroid formulations together, too,” she said. “For example, I would not choose a synthetic pyrethroid dust to use with a neonicitinoid.”
She tends to use the repellent classes when treating for American and Smoky Brown roaches, adding she hasn’t tried other classes because the synthetic pyrethroid liquids and dusts seem to work great on the larger species.
According to Marshall, multiple classes can even all be found in the same product, further simplifying his treatment plan, which is developed in an initial inspection. “We access the situation during the initial inspection and utilize the chemicals we think will work best for the situation,” Marshall said. “We test our theory in the initial treatment and adjust as necessary.”
Those adjustments depend on the property, situation and issues, but they generally come quarterly or biannually. In his experience experimenting with active classes, he said he has gotten great results by mixing and matching a variety of name brand products.