Bed bug aggregation on dirty laundry: a mechanism for passive dispersal

William T Hentley,Michael T Siva-Jothy,Ben Webster,Sophie E F Evison

doi:10.1038/s41598-017-11850-5

Abstract

Bed bugs have shown a recent and rapid global expansion that has been suggested to be caused by cheap air travel. How a small, flightless and anachoretic insect that hides within its host’s sleeping area manages to travel long distances is not yet clear. Bed bugs are attracted to the odour of sleeping humans and we suggest that soiled clothing may present a similarly attractive cue, allowing bed bugs to ‘hitch-hike’ around the world after aggregating in the laundry bags of travellers. We show that (1) soiled clothing is significantly more attractive than clean clothing to active bed bugs moving within a bedroom sized arena and (2) elevation of CO2 to a level that simulates human occupancy in the same arena appears to initiate search behaviour rather than direct it. Our results show, for the first time, how leaving worn clothing exposed in sleeping areas when travelling can be exploited by bed bugs to facilitate passive dispersal.

Highlights

The common bed bug Cimex lectularius L. has recently undergone a global resurgence[1] which has been partly attributed to the increase in low cost international travel[2]
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
We did not observe bed bugs aggregating on the side of the room with the CO2 source, but instead found an increased likelihood of bed bugs leaving their refuge

Summary

Introduction

The common bed bug Cimex lectularius L. has recently undergone a global resurgence[1] which has been partly attributed to the increase in low cost international travel[2]. The ability of, and preference for, bed bugs to use established hiding places is well documented[1, 7] and is an important phenomenon in the problems associated with their control It appears to be at odds with an ability to sequester and hide themselves in ‘novel’ hiding places such as suitcases and clothes in order to facilitate passive dispersal. In contrast to their dispersal mechanisms, the host-seeking behaviour of the bed bug (and other haematophagous insects8) has received considerable empirical attention[9] and is known to involve a combination of cues including host thermal, olfactory and visual signals[10,11,12] with CO2 playing an important modulatory role[12]. We used a bedroom-scale experimental arena to determine whether (a) bed bugs would leave their refugia, (b) bed bugs would aggregate on soiled clothing, and (c) whether elevated CO2 (to simulate a human host in the room) modulated bed bug behaviours

Methods

Results

Conclusion