Smelling your way to food: can bed bugs use our odour?

Abstract

SUMMARYThe resurgence in developed countries of the common bed bug, Cimex lectularius, has led to a search for new sustainable methods to monitor and control this human ectoparasite. Because of increased resistance to insecticides, traps baited with attractive cues are considered a promising method to be developed into efficient monitoring tools for bed bugs. Despite their potential as attractants, only a few studies have investigated the odorant cues implicated in the attraction of bed bugs to human hosts. In this study, we used aeration extracts from human volunteers to assess the role of olfaction in host searching by bed bugs. By coupled gas chromatography and single sensillum recordings on all the antennal sensilla, we measured the electrophysiological response elicited by the compounds present in our human odour extracts. Only five compounds were clearly detected by the olfactory receptor neurons housed in the smooth-peg sensilla of the bed bugs. We tested the behavioural effect of these extracts in a still-air arena and showed a gradient of repellence linked to the dose, as well as a higher propensity of local search behaviour associated with human odours containing a lower ratio of 6-methyl-5-hepten-2-one to C 7 -C 10 aldehydes. We conclude that human odour alone has a weak influence on the behaviour of C. lectularius and we propose that human kairomones may have a significant impact on bed bug behaviour in combination with heat and carbon dioxide, the only two currently known attractive vertebrate cues used by bed bugs for host seeking.

Feel the heat: Activation, orientation, and feeding responses of bed bugs to targets at different temperatures

“…Host seeking appears to be highly mediated by a circadian rhythm, with unfed bed bugs showing increased activity levels at night (Reis and Miller, 2011;Romero et al, 2010). When searching for a host, bed bugs actively orient to three host-related stimuli: body odors (Harraca et al, 2012), CO 2 (Anderson et al, 2009) and heat (Rivnay, 1932). Since its discovery as an attractant, heat has been evaluated through trap catch assays designed to understand bed bug orientation and improve detection and monitoring of infestations (Anderson et al, 2009;Singh et al, 2012;Wang et al, 2009).…”

New methods for field collection of human skin volatiles and perspectives for their application in the chemical ecology of human/pathogen/vector interactions

“…Numerous studies have investigated the chemical composition of human skin volatiles emitted by axillae (Zeng et al, 1996;Curran et al, 2005;Natsch et al, 2006), forearms and hands (Bernier et al, 2000;Zhang et al, 2005;Gallagher et al, 2008;Syed and Leal, 2009;, feet (Qiu et al, 2004;Ara et al, 2006;Kanda et al, 1990;Caroprese et al, 2009), or even the whole body (Logan et al, 2008;Harraca et al, 2012). Deciphering human body odours may provide tools for diagnosing human diseases or infections (Prugnolle et al, 2009), and has proved to have various applications in forensic studies (Prada and Furton, 2008).…”

Blood constituents as phagostimulants for the bed bug,Cimex lectularius L

“…Marx (Marx, 1955) suggested that besides heat, CO 2 produced by hosts may play a role in attracting bed bugs, and this compound is usually incorporated in traps for monitoring bed bug infestations (Anderson et al, 2009;Wang et al, 2012). Although host odors are thought to play a role in the host-seeking process, chemicals collected from human emanations have not been shown to be attractive in behavioral assays (Harraca et al, 2012).…”