Alarm Pheromones and Chemical Communication in Nymphs of the Tropical Bed Bug Cimex hemipterus (Hemiptera: Cimicidae)

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.

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

“…Bed bugs are repulsed by air movement and therefore do not use coupled anemotactic-chemotactic responses to direct their path (Aboul-Nasr and Erakey, 1968;Weeks et al, 2011) (V.H., personal observation on servosphere). Instead, bed bugs seem to use their antennal olfactory system to detect odorant cues at close range, such as during their intraspecific interactions (Siljander et al, 2008;Harraca et al, 2010a;Liedtke et al, 2011;Weeks et al, 2011).…”

“…For this purpose, odorant cues used by the bed bugs are considered novel constituents in the integrated bed bug management. Consequently, odours emitted by the bed bugs themselves, such as alarm pheromones and aggregation semiochemicals, have been recently investigated (Siljander et al, 2008;Harraca et al, 2010a;Liedtke et al, 2011;Weeks et al, 2011). In spite of the potential of host attractants for both targeted control treatments and surveillance, there is limited knowledge of the identity of these semiochemicals (e.g.…”

Bed Bug Detection: Current Technologies and Future Directions

“…The resurgence of bed bug populations has resulted in a renewed interest in the chemical ecology of these pests, which in turn, has led to the discovery of two new alarm pheromones and new insights into how bed bugs use them. [64][65][66][67] Although alarm pheromones have been incorporated into some trapping or monitoring devices, they have also been used as part of a control strategy, 68 and alarm pheromones may play a role in canine detection of bed bugs (discussed below).…”

Mechanisms that contribute to the establishment and persistence of bed bug infestations

“…Bed bug chemical ecology can be divided into two major fields: chemicals involved in the location of the host and those for interaction between bed bugs (j\nderson et al, 2009;Harraca et al, 2010a;Johnson, 1941;Liedtke et al, 2011;Reinhardt and SivaJothy, 2007;Siljander et al, 2007;Usinger, 1966;Weeks et al, 2011). Both of these processes are critical to bed bug survival in a new environment.…”