08
Dec
Least-Toxic Chemicals Show Promise for Bed Bug Control, But Non-Toxic Practices Remain the Best Solution
(Beyond Pesticides, December 8, 2017) Less toxic oil-based insecticides are showing promise for the treatment of bed 
bugs, according to a study published this month in the Journal of Economic Entomology. The common bed bug has seen a significant resurgence in the U.S., and with the pests found to be resistant to a broad range of modern, toxic insecticides, pest control operators are searching out new, safer ways to manage infestations. “So far there are no reports of resistance to these oils,” said study author Changlu Wang, PhD to Entomology Today. “It is very difficult for insects to develop resistance to them since they are not neurotoxins.”
A range of 18 essential oils, concentrated liquids containing aromatic compounds derived from plants, were tested for their toxicity to bed bugs that were retrieved from an infested building in Indiana. Paraffin oil, a colorless and odorless mineral oil, as well as three silicone oils, similarly colorless and odorless oils used in various personal care products and medications, were also screened for their toxicity to bed bugs. Scientists observed the bed bugs in a laboratory setting for two weeks before moving to another round of experimentation.
Of the 22 oils tested, paraffin oil and the three silicone oils displayed the greatest bed bug mortality, with blood orange oil and cedarwood oil showing the most toxicity of the essential oils. The authors suspect that the higher rate of bed bug mortality through silicone and paraffin oil exposure is primarily a physical mode of action, where the oils suffocate the insects by entering their tracheal system.
Scientists also compared cedarwood oil, geraniol, and formulated product called EcoRaider, which contained both cedarwood and geraniol in a formulated product. The formulated product EcoRaider resulted in a significantly higher mortality than either of the individual essential oils alone. The study suggests that this may because the pure essential oils are highly volatile and evaporate quickly, while the EcoRaider efficacy is likely a result of additional surfactants in the EcoRaider product.
Silicone oils, paraffin oil, and the formulated product EcoRaider all showed relatively similar toxicity to bed bugs. Given that recent studies have revealed high levels of resistance to widely used neonicotinoid and pyrethroid insecticides, these products may present a viable management option when paired with other techniques. It is important to note that this current experiment was conducted in a laboratory setting, and bed bugs have been shown to display significant variation between toxicity and mortality in the lab and in actual infested buildings and residences. In real world settings, certain bed bug populations may develop stronger resistance mechanisms, and in addition, the bugs have a greater opportunity to avoid insecticide applications. Research in 2012 found that even long-term laboratory populations of bed bugs susceptible to common insecticides were unharmed after given a thin cloth as a cover. Given the bug’s propensity to hide in cracks and crevices of beds, furniture, bags, and other household items, it is evident that spraying any product, even a least toxic one, may not be the best solution for an infestation.
Beyond Pesticides recommends an integrated approach to bed bug management that focuses on cultural practices first and foremost. This includes eliminating clutter where the bugs can hide, encasing and isolating certain furniture, thorough vacuuming, caulking and sealing cracks and crevices around bed frames, floors, walls, baseboard edges, and moldings, and laundering fabrics and clothing. Heat and steam treatments are good options that are generally effective at eliminating or drastically reducing most bed bug infestations. Least-toxic chemicals, such as the ones in the present study, but also borates and diatomaceous earth, should be considered as a last resort, and used carefully.
To get a handle on a bed bug infestation in your home or property, don’t reach for a chemical -see Beyond Pesticides article “Got Bed Bugs? Don’t Panic.” as well as the ManageSafe fact sheet on bed bugs. And for more information see the Bed Bug program page or call the office at 202-543-5450 or email at [email protected] for assistance.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
