In the absence of a human host, bed bugs are attracted to soiled clothes according to a study in Scientific Reports this week. The authors suggest that leaving worn clothes exposed in sleeping areas when travelling may facilitate the dispersal of bed bugs.
The common bed bug (Cimex lectularius) has recently undergone a global resurgence, which has been partly attributed to the increase in low cost international travel. One possible mechanism facilitating long-range dispersal is that the insects find their way into clothing and/ or luggage.
William Hentley and colleagues conducted experiments in two identical, temperature-controlled rooms in which four tote bags of clothes were placed (two containing soiled clothes, two with clean clothes) in the presence of bed bugs. In each run of the experiment, one room received an increased concentration of C02 to simulate a human breathing. The authors found that in the absence of a human host, bed bugs were twice as likely to aggregate on bags containing soiled clothes compared to bags containing clean clothes. The authors also found that for increased concentrations of CO2, bed bugs were more likely to leave their refuge and initiate host-seeking behaviour.
The authors argue that residual human odour on soiled clothes acts as an elicitor of host-seeking behaviour. Consequently, soiled clothing left in an open suitcase, or left on the floor of an infested room may attract bed bugs.