Various-sized Petri dish arenas were used for color harborage experiments. (A) Smaller Petri dishes were used for the two-choice assays. (B) Larger petri dishes were used for the seven-choice assays.
According to a new study published in the Journal of Medical Entomology, researchers from the University of Florida and Union College (Lincoln, Nebr.) tested a theory of whether bed bugs prefer certain colors for harborage. The results? The bed bugs in this study prefer red and black, and tend to avoid green and yellow.
In an interview with Josh Lancette, Entomology Today (the online publication of the Entomological Society of America), study co-author Dr. Corraine McNeill explained that they “originally thought the bed bugs might prefer red because blood is red and that’s what they feed on. However, after doing the study, the main reason we think they preferred red colors is because bed bugs themselves appear red, so they go to these harborages because they want to be with other bed bugs, as they are known to exist in aggregations.”
In the study, interesting variations exist among male and female choices, whether the bugs were hungry or fed, their age, and whether they were in groups or alone. The authors theorize that the bugs avoid yellow and green colors “because those colors resemble brightly lit areas.”
“I always joke with people, ‘Make sure you get yellow sheets!’” Dr. McNeill told Entomology Today. “But to be very honest, I think that would be stretching the results a little too much. I think using colors to monitor and prevent bed bugs would have to be specifically applied to some sort of trap, and it would have to be used along with another strategy for control. I don’t know how far I would go to say don’t get a red suitcase or red sheets, but the research hasn’t been done yet, so we can’t really rule that out completely.”
In his article, Lancette reports that the study almost didn’t happen. It only came to be at the urging of 2015 PMP Hall of Famer Dr. Phil Koehler. As Dr. McNeill tells Entomology Today:
“My advisor at the time, Dr. Phil Koehler, said to me, ‘You know, I don’t think we have any recent studies regarding bed bug vision or how they respond to colors if they’re looking for a harborage.’ At first I laughed at him and said, ‘Oh Dr. Koehler, bed bugs can’t see color or use color in that way! That’s ridiculous.’ However, he encouraged me to not push the idea out the door until we had tried some preliminary tests. So, we did some preliminary testing and found that the bed bugs were specifically going to certain colors over others, especially as it pertained to harborages. From there, we took the idea and ran with it.”
About the Author
Heather Gooch is the editor-in-chief for PMP magazine. She can be reached at hgooch@northcoastmedia.net or 330-321-9754.
For the past 14 years I have done over 1000 bedbug treatments, and I could tell you that the colors black, white, blue, yellow, pink, purple, green, beige, red, etc…. Color doesn’t have to do with anything. So stop misleading the people……
Edwin, thanks for writing! The point of the study was to show bed bugs have a preference, not that they 100 percent avoid certain colors. It’s just like how we can’t avoid eating our veggies now and then, even if we’d prefer ice cream all the time. The researchers were also very careful to point out that this is a preliminary study and by no means definitive. —The Eds.