A few years ago some interesting research came out that bed bugs preferred to harbour (camouflage?) on black and red surfaces and avoided white and yellow ones. That was very interesting. Shortly after that the Climb Up Interceptor started being available with black tape on the outside. And after that a copy of the Interceptor called the “Black Out Bed Bug Detector” became available making claims that it was more attractive to bed bugs.
Another interesting study pitted different types of interceptor devices against each other in head to head comparisons and found that indeed, in an experimental tank with each interceptor an equal distance from the walls of the tank, that the black interceptors caught more bugs. Again interesting and it does create some credence that the black color was useful. So far this information has not convinced me to purchase black interceptors because they would be much more difficult to inspect both in the pitfall and on the exterior where the bugs are occasionally found harbouring.
In my experience most of the bed bugs are caught in the interceptors in the darkest corner – for example if the bed is in a corner the bed leg in the corner has the most bugs. The reverse is also true that the bed leg most exposed (the bed leg diagonal to the corner leg) has the least bugs. I assume the bugs are attempting to access the host in the darkest and most hidden method. (The pattern outlined above is not always true as a room self treated with aerosol pyrethrins has a much more scattered pattern of trapping. Bugs with sublethal doses of pyrethrin behave differently than those with no poisoning.)
I would really like to see some in situ testing done on the color black to determine if the bugs actually fell into black interceptors more often than white ones. The interceptor experiment tank may have inadvertently funnelled the bugs to what the bed bugs perceived as the safest parts (the “corner” bed leg) of the experiment tank. As such the experiment would have determined that bed bugs attempted to access the experimental lures by the “safest” route.
To test this theory I suggest placing white interceptors on the three bed legs nearest the wall (assuming the bed is in the corner) and a black one on the most exposed bed leg which is typically least desirable. If bugs were caught in this device more often than would otherwise have been the case I would then be convinced that the color black actually helps with the trapping. My gut tells me there would be little or no improvement in the catch rate and the primary driver of where the bugs are caught is the hidden environment.
It would be important to experiment only in rooms that have not been treated as we want to exclude the effect of pyrethroid poisoning from the results.