Wang, Changlu; Gibb, Timothy; Bennett, Gary W.; Mcknight, Susan (2009) Bed Bug (Heteroptera: Cimicidae) Attraction to Pitfall Traps Baited With Carbon Dioxide, Heat, and Chemical Lure Journal of Economic Entomology, 102:4, 1580-1585. (free PDF download)
Dr. Wang and colleagues have published a new paper on bed bug traps. It’s great to see them pursuing affordability. Dry ice instead of a pressurized tank; both deliver CO2 quite well—although it should be noted of course that dry ice requires safe handling. (This is a note about a research paper. Please do not try this at home. Carbon dioxide can suffocate you and your loved ones. Go ahead and try the heat trap, though! There is a photograph in the article, an inverted cat dish, fabric, hand warmers…)
They found that carbon dioxide and heat (from hand warmers) are good at catching bed bugs, but carbon dioxide is more effective.
Getting the right proportion and mix of chemical attractants is apparently difficult and so chemical attractants did not make that much of a difference in their trials:
The small pitfall traps made of plastic dishes provide an efficient method to quantify the attractiveness of nonchemical and chemical lures to bed bugs. Among the three attractants (CO2, heat, and chemical lure) tested, we found that CO2 was by far the most effective in attracting bed bugs, supporting the conclusion by Anderson et al. (2009). Additionally, we found that heat alone was effective in attracting bed bugs. Chemical lure increased trap catches in two of the three replicates at 6 h and in all replicates at 21 h. However, the differences were small. This result was consistent with our preliminary tests showing weak attractiveness of chemical lures.
Treating for bed bugs in unoccupied premises is extremely challenging, and so it is interesting to note that they tested a version of the trap in a vacated apartment and caught 505 bed bugs thirteen days after vacancy and 113 bed bugs twenty-one days after vacancy.
When you read this, I don’t want you to miss this:
The single test in a vacant apartment showed that in heavily infested apartments 1) visual inspections could seriously underestimate the bed bug numbers, 2) large numbers of bed bugs were not on the furniture and survived the chemical and nonchemical treatment, and 3) baited-pitfall traps were helpful in monitoring effectiveness of bed bug treatments. From our observations, bed bugs frequently travel from infested apartments to the hallways in a multiunit apartment building (C.W. et al. unpublished data). It is logical to infer that bed bugs are more likely to disperse into neighboring apartments through hallways when their host is no longer present. Therefore, using baited traps in unoccupied infested apartments may reduce the risk of bed bug dispersal between adjacent units in multiunit dwellings.
Best check those apartments across the hall then.
You can download another recent article from this group of researchers which described an evaluation of IPM treatments and the now-commercialized interceptor trap for use underneath bed posts and furniture legs here (free PDF download). No doubt there will be more and better trap designs out there soon.
They thought traps were for ‘primitives’ and here we are desperate for them.