In light of recent research indicating bed bugs can travel much further through apartment buildings than we previously thought (read about study here), selecting an effective treatment is essential to containing and ending infestations.
Difficult infestations tend to occur when bed bugs travel through outlets and utility lines into the hard to treat wall voids, ceilings and floors. This often occurs when bed bug populations are permitted to grow due to improper or no treatment. This appeared to be what was happening at a housing authority I recently reviewed a bed bug protocol for. On the surface they had all the components of a good integrated pest management (IPM) plan. Staff used a steamer and vacuum when necessary. The housing authority provided resident education and assistance with treatment preparation. They did a great job tracking and responding to infestations with treatments, yet they had a persistent and growing infestation. So what was the problem? How could the infestation be getting worse? Then I noticed that a new natural, essential oil-based 'green' product was being used in all treatments. While I appreciate they were trying to use a non-synthetic pesticide to reduce the resident’s exposure to chemicals, I could find no research indicating this product had been tested for efficacy. A quick email to a few University researchers confirmed my suspicion. We could not say whether or not this product worked because it had not been tested.
Bed bugs are particularly hard to control because of their food source. Us. Therefore, poison baits (boric acid) cannot be used. This creates a challenge. Pesticides must be able to kill on contact or enough must be picked up on the bed bug’s feet as they walk through it.
Several essential oil-based or 'green' products were recently tested at Rutgers and most were shown to come up short. Most of the materials tested killed a very low percentage of the bed bugs, only two of nine materials tested controlled over 90%. The bed bugs killed in this research project had forced exposure to the products in laboratory conditions. There was nothing that would block bedbug contact, such as clutter, that would be encountered in the real world. In addition, the researchers found there was no repellancy from any of the materials tested, (nor from sonic devices). It appears nothing will deter a bed bug when CO2 is present, which is what bed bugs use to locate humans.
Because essential oil-based materials rely on direct contact to achieve control, often a mechanic means of control, such as a vacuum or steamer (or even a swatter!) would be just as effective. If you are searching for an effective, non-chemical pesticide, stick with a researched product such as a silica-based desiccant dust (ie. CimeXa). Desiccants can be used in hard to reach spots (like wall voids) and remain effective as long as they are dry and the bugs can walk through the dust.
The bottom line is there is no silver bullet. The best way to realize good control is through an integrated program. Effective pesticide controls, including 'green' materials, are only one tool in the IPM toolbox. Any sprays should be used in conjunction with monitoring, sealing crawlways, mechanical controls, sanitation and cultural controls, such as removing clutter. Sprays (chemical or essential oil-based) may assist with control, but only when part of a larger IPM program. And only when they are proven to be effective through valid testing. Do you have a question about the product your pest control company is using? Ask us StopPests@cornell.edu.