Bed Bug Research Round-Up

Research from two U.S. universities show how bed bug control can be improved. One study offers practical advice to use now, and the other holds promise for more effective pesticides in the future.

1. Containerized Fumigation Eliminates Insecticide-Resistant Bed Bugs from Vehicles and Household Items

Virginia Tech University researchers have documented the efficacy of sulfuryl fluoride in eliminating bed bugs from vehicles and trailers filled with furniture and personal belongings.

According to Dr. Dini Miller and Dakotah Todd, a master’s student in the Virginia Tech entomology program, the field evaluation achieved 100 per cent mortality of bed bug eggs, nymphs and adults.

Todd believes fumigation is superior to other bed bug treatment methods for vehicles because the molecule size of sulfuryl fluoride can access spaces that spray insecticides cannot. And unlike heat, it will not damage console screens and sensitive electronic equipment found in today’s vehicles. “Fumigation is the only tool we have for getting 100 per cent penetration into cracks, crevices and under plastic panels,” he explains. 

Using containerized fumigation, it also was possible to eliminate bed bugs from infested furniture, household items and personal belongings loaded into trailers. This lets clients keep items that may be difficult or costly to replace. It also offers a solution for eliminating insecticide-resistant bed bug populations and for treating sensitive items like artwork.

Containerized fumigation is a small-scale operation (compared to structural fumigation), so it is relatively inexpensive to undertake. It can be performed in a customer’s driveway or at the pest control company’s facility. While special training is required, it is not a difficult process to learn, says Miller.

“You don’t have to be in the business of structural fumigation to offer this as an option for treating vehicles or household items. Fumigation is a proven and reliable method for bed bug control,” she says.

Learn more about performing containerized fumigation per the University of Virginia field study.

2. Essential Oils Restore Pyrethroid Effectiveness Against Bed Bugs

Researchers from Purdue University have discovered how plant-based essential oil compounds act on bed bug physiology and how these oils can improve the lethality of pyrethroids.

“Our findings show that essential oils can kill bed bugs, but the combination of essential oils and pyrethroid insecticides has a synergistic effect,” says Ameya Gondhalekar, a research associate professor in entomology.

This is especially important when dealing with bed bugs that have developed resistance to pyrethroids like deltamethrin.

Resistant bed bugs possess multiple mechanisms to resist pyrethroids, including overactive levels of an enzyme called cytochrome P450, which degrades deltamethrin. Gondhalekar and former Ph.D. student Sudip Gair, however, found that essential oil compounds (thymol from thyme, carvacrol from oregano and thyme, eugenol from clove) can bind to and deactivate that enzyme. This lets deltamethrin do its job on the bed bug’s nervous system, killing the pest.

The researchers combined single doses of deltamethrin and essential oil compounds, which they anticipated would kill 25 to 50 per cent of resistant bed bugs. Instead, they found the combination killed more than 90 per cent of the resistant bed bugs.

“The essential oil compounds were able to neutralize those enzymes, allowing the deltamethrin to do its job,” explains Gaire.

Gondhalekar’s lab is researching potential formulations of essential oils and pyrethroids with the hope of maximizing insecticide effectiveness.

Learn more about these findings, which originally were published in the journal Pesticide Biochemistry and Physiology in 2020 and 2021.