Determining if heat causes bed bugs (Cimex lectularius L.) to emit alarm pheromones and the response of nearby conspecifics

Many insects use pheromones as a means to communicate messages to the same species or to different insect species. The chemical ecology of the bed bug, Cimex lectularius L., has been recently studied in order to better control their infestations. Bed bugs are repelled by high temperatures, which are used to control their infestations. But, if bed bug alarm pheromones, a 70/30 blend of (E)-2-Hexenal and (E)-2-Ocetenal, play a role in heat repellency is unknown. Therefore, the goal of this research was to: 1) determine if bed bugs emit alarm pheromones in response to heat exposure and 2) how conspecifics react alarm pheromones emitted by heat exposed bed bugs. Using a SIFT-MS (soft ion flow tube mass spectrometer), it was found that bed bugs responded to heat exposure by emitting their alarm pheromones. The laboratory population emitted higher quantities than the tested field population. Females emitted similar amounts of alarm pheromones compared to males. In separate experiments, it was shown that conspecifics from both populations reacted to alarm pheromones emitted by heated bed bugs by frantically moving within small areas. Finding that bed bugs emit alarm pheromones after heat exposure has important implications for how they respond to thermal remediation in the field.