Insecticide resistance has remained a hot topic in cockroach control, and our industry has been battling it for many years. Residual insecticides and bait products are essential go-to tools for controlling German cockroaches, and it’s possible you have faced a population that has developed resistance to some of the products you use to manage them. Let’s discuss some common FAQs about cockroaches and insecticide resistance:
Have German cockroach populations demonstrated resistance to active ingredients found in cockroach bait formulations?
Yes, there is evidence of field populations that exhibit resistance to various bait active ingredients (AIs), including fipronil, clothianidin, hydramethylnon, and indoxacarb. In a 2021 publication in the Journal of Economic Entomology, researchers at the University of California, Riverside evaluated field collected German cockroach susceptibility to several common AIs. The conclusions of this study showed some level of resistance to most of the baits tested.
How do cockroaches develop resistance to specific types of insecticides?While we don’t exactly know the full extent of resistance across the US, we do know how it happens. Continual or repeated exposure to applications of products containing AIs with the same mode of action in a given area can lead to the development of resistance within a population. Additionally, using pesticide products at lower than labeled rates can also contribute to the problem. So always follow the rates provided on the label for the specific pest, site, and infestation level at hand.
What are the signs of insecticide resistance?If you observe a change or reduction in control or efficacy of a product, this is often a sign of resistance development. Continual applications and population exposure to the same AI or mode of action can lead to an increase in resistant individuals which can dominate a population.
What are the recommendations to delay or manage resistance development in an insect population?Avoiding the consecutive use of a product, exercising proper product rotation (choosing products with different modes of action), and good IPM practices can help us to avoid or delay insecticide resistance. It’s also helpful to be informed of the IRAC classification for each of the AIs in the products used in your service. Knowing the IRAC group will help you with good rotational decision making. See link here for more information.
What is a mode of action (MOA)?The mode of action is the way a specific active ingredient controls the pest. IRAC groups are based on MOA, which considers the biological pathway or target site in the insect’s body that the AI affects. This is why it’s important to not simply rotate brand names, but rotate the MOA.
What CSI products can I incorporate into my cockroach management program, and what active ingredients do they contain?Our comprehensive portfolio of products includes formulations such as aerosol, foam, bait, flushing, and liquid residual options. Some examples of CSI products you can integrate into your cockroach management program are mentioned below. These products can bring value and results to your service and represent AIs from different groups including 3, 4, 7, 15, and 22:
