Abstract
The recent resurge of bed bug infestations (Cimex spp.; Cimicidae) and their resistance to commonly used pesticides calls for alternative methods of control. Pheromones play an important role in environmentally sustainable methods for the management of many pest insects and may therefore be applicable for the control of bed bugs. The tropical bed bug, Cimex hemipterus, is a temporary ectoparasite on humans and causes severe discomfort. Compared to the common bed bug, Cimex lectularius, little is known about the chemical signalling and pheromone-based behaviour of the tropical species. Here, we show that the antennal morphology and volatile emission of C. hemipterus closely resembles those of C. lectularius and we test their behavioural responses to conspecific odour emissions. Two major volatiles are emitted by male, female and nymph C. hemipterus under stress, (E)-2-hexenal and (E)-2-octenal. Notably, nymph emissions show contrasting ratios of these compounds to adults and are further characterized by the addition of 4-oxo-(E)-2-hexenal and 4-oxo-(E)-2-octenal. The discovery of this nymph pheromone in C. hemipterus is potentially the cause of a repellent effect observed in the bio-tests, where nymph odours induce a significantly stronger repellent reaction in conspecifics than adult odours. Our results suggest that pheromone-based pest control methods developed for C. lectularius could be applicable to C. hemipterus, with the unique nymph blend showing promising practical properties.
Highlights
As their generic name suggests, the tropical bed bug, Cimex hemipterus, is a hematophageous insect, parasitizing on human hosts living in equatorial regions [1]
Exploiting alarm pheromones for this purpose is of interest and a recent study on C. lectularius showed promising results: a widespread tool for insect control has been the use of desiccant dusts, which damage the water proofing cuticular lipids of pests and causes death by desiccation
Almost nothing is known about the chemical ecology of C. hemipterus and this study investigates three major constituents of chemical communication: the morphology of the main receptive organ, the volatiles emitted under stress and the behavioural responses induced by these volatiles in conspecifics
Summary
As their generic name suggests, the tropical bed bug, Cimex hemipterus, is a hematophageous insect, parasitizing on human hosts living in equatorial regions [1]. These records suggest a geographic range expansion and the two species have been reported to thrive as mixed infestations [17] This is cause for concern because pheromone-based control methods designed for C. lectularius may not prove effective for combating C. hemipterus infestations, as species-specific blend composition and ratios are often very important in chemical communication systems [12,18]. By more detailed SEM imaging of the external antennal anatomy, we hereby aim to generate a sensilla map for C. hemipterus comparable to that of an existing map for C. lectularius produced by Steinbrecht and Muller [20] This will allow investigations into the claims of Singh et al [19] that the tropical species (C. hemipterus) has double the number of chemosensitive sensilla compared to C. lectularius as well as exhibiting sexual dimorphism, a characteristic not evident in the common bed bug [20]. By identifying the constituents of volatile emissions using coupled gas chromatography mass spectrometry (GC-MS) and assessing behavioural responses to these volatile emissions using bioassays, our findings aim to contribute to the development of population control agents which have far focused exclusively on C. lectularius [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
