Insecticide Sprays Ineffective for Cockroach Control

Nobody wants cockroaches in their home, especially since these pests can cause and worsen allergies in children, transmit diseases and bacteria, and contaminate foods.

If you find cockroaches in or around your home, do you reach for a do-it-yourself spray product? Well, you might not want to waste your money!

New research shows that some common consumer-grade insecticide sprays don't work to get rid of cockroach infestations. The study focused on products containing pyrethroids, which is a group of pesticides commonly found in many household insecticide products. Examples of pyrethroids include the active ingredients bifenthrin, cypermethrin, and permethrin.

In the study, both liquid and aerosol pyrethroid products killed less than 20% of German cockroaches on sprayed surfaces. Even when cockroaches were confined to the sprayed surfaces, most products took 8 to 24 hours to kill them, with some taking up to 5 days.

Research has also shown that frequent use of pyrethroid insecticides for cockroach management had caused the insects to develop resistance to these products.

So, what can you do to effectively control cockroaches?

Identifying the species present is important since some cockroaches live and breed indoors, while others live and breed outdoors. Knowing which cockroach species you have will allow you to focus control efforts on the correct location, using methods that are effective for managing that specific type of cockroach.

Pesticides alone will not solve a cockroach problem. Use pesticides indoors only if the cockroach population is reproducing and living in your home, not for the occasional intruder. Use insecticide bait products in combination with other non-chemical control methods, such as exclusion and sanitation.

Hiring a professional pest control service that takes an IPM approach can be helpful in reducing serious indoor cockroach infestations but can be also be expensive. Professionals have the tools, experience, and knowledge to better address serious pest issues. Infestations in multi-unit housing, such as apartment complexes, can be especially difficult to control and often requires a community-wide effort.

For more detailed management information, see the Pest Notes: Cockroaches.

[Adapted from an article published by the Entomological Society of America on August 14, 2024.]