In the event bed bugs are suspected in an account, the first step should be to confirm that an infestation actually exists. Bed bugs are often suspected simply due to the presence of physical symptoms (e.g., itchy welts). In the absence of a sample it is important to conduct an inspection to look for evidence of bed bugs. Evidence may be seen in the form of fecal deposits (otherwise referred to as spotting), caste skins (exuvia), carcasses or live bugs.
Care should also be taken when examining suspected evidence of bed bugs to avoid misidentification. German cockroach fecal deposits resemble the feces produced by bed bugs but can be differentiated by their rough texture compared to the smooth deposits produced by bed bugs. In addition, the feces produced by bed bugs (dried excreted blood) are water soluble and will smear when wetted with a damp cloth while those of cockroaches will not.
Care also should be taken when examining shed caste skins (exuvia). Shed skins from dermestid beetle larvae are often found in many of the same places as bed bugs such as on tack strips. If care is not taken, shed skins from dermestid larvae can be easily mistaken for shed skins from bed bugs.
Immature cockroaches are often in the same environments as bed bugs and can be confused by those not trained in proper identification. Likewise, psocids, a common structural pest, are similar in appearance to first instar bed bugs and can be easily confused if not examined carefully. Individuals who are not familiar with bed bugs may also confuse ticks with either immature or adult bed bugs. Bird or rodent mites can bite occupants of structures and can also be easily confused with first instar bed bugs.
Once it has been confirmed that the sample is in fact a cimicid, it is important to determine which species is infesting the structure, so it is essential that the samples be properly identified. Just because it looks like a bed bug, one cannot assume it is Cimex lectularius.
Bed bugs, bat bugs and bird bugs are all very similar in appearance and require careful examination for correct identification. Careful observation and environmental clues can be helpful in tipping off the pest management professional that they may be dealing with something other than a bed bug. For example, an alternate host should be suspected when bugs are readily seen on the walls, ceiling or wall/ceiling junctions but are absent from sleeping areas, and the occupants are not reporting being bitten.
While these types of clues are reason to suspect bird bugs or bat bugs, samples should be collected for positive identification. If bats, chimney swifts, swallows, pigeons or poultry are serving as the primary host, different control measures will be required than would be for C. lectularius (common bed bugs) or C. hemipterus (tropical bed bugs).