Skip to content

What Are Pyrethroid Resistant Bed Bugs?

Just when you thought having bed bugs couldn’t get any worse, the pyrethroid resistant bed bug came along.

Pyrethroid Resistant Bugs

What is a pyrethroid resistant bed bug?

Gradually, throughout the United States, small pockets of bed bugs have built up a resistance to pyrethroid insecticides that are commonly used to eliminate bed bugs due to their low cost and fast acting nature. Pyrethrum, not to be confused with pyrethroid, is an insecticide derived from dried flower heads, specifically Chrysanthemum cinerariifolium and Chrysanthemum coccineum. However, due to its rising cost and difficulty to source mid way through the 20th century, chemists began researching ways to produce pyrethrums synthetically. Shortly thereafter, pyrethroids were born. Pyrethroids include a large variety of artificial pyrethrums and have proven very effective in killing bed bugs. However, certain colonies of bed bugs have built up immunity to these synthetic chemicals. These bed bugs tend to have a tough outer shell that prevents the insecticide from entering their bodies. Crazy, right? Times article on Why Bed Bugs are Becoming So Much Harder to Kill, discussing the studies on chemical types and usage. The reduced effectiveness of these chemicals is considered a main cause of the bed bug’s resurgence over the last decade, especially in big cities. And there’s more. Due to their hitchhiking skills, pockets of these bed bugs are not isolated to one particular region of the United States. They can be anywhere, literally. Unfortunately, there is no known way to identify a pyrethroid resistant bed bug by its appearance. You can assume you are dealing with a pyrethroid-resistant strain if the continued use of a pyrethroid-based product does not take care of the problem. The EPA breaks down some of the types of pesticides used to control bed bugs.

How do I identify pyrethroid-based products?

Pyrethroid chemicals come in different variations but often end in “thrin” or “ate.” In most cases, these chemicals will get rid of the bed bugs quickly and efficiently. However, if you don’t want to take any chances, use Harris Black label. Our black label is approved for use in residences and kills even the toughest pyrethroid resistant bed bugs. For more information about effective application of Harris bed bug products, see this post.