Boric Acid as a Cockroach Insecticide

Boric acid has a highly toxic effect on cockroaches but poses relatively little danger to people or pets, making it a popular insecticide for private kitchens and restaurants. It emits no odor, and a tiny amount will kill cockroaches.

Application

Manufacturers sell boric acid in powder form. In an article on cockroaches, University of Kentucky entomologist Mike Potter recommends applying a thin coating of boric acid "dust" to surfaces where cockroaches roam, especially in cracks and crevices where they tend to take up residence. The free space behind ovens or refrigerators is another good site to apply boric acid.

Toxicity

As the cockroaches pass through the treated zones, boric acid dust sticks to their antennae and legs. As a cockroach cleans these parts with its mouth, it eats the boric acid. Colorado State University Extension entomologist F.B. Peairs notes in an article on the extension website that boric acid takes full effect after one week.

Considerations

Cockroaches will avoid a heavy buildup of boric acid powder. Apply the thinnest possible layer of dust to treatment areas. Potter advises against applying boric acid to food preparation surfaces.

References

• University of Kentucky College of Agriculture: Cockroach Elimination
• Colorado State University Extension: Cockroaches