Family dinner or dine alone: Do immature bed bugs make it to the “table” on their own?

Post-ovipositional parental care has evolved independently in a number of insect orders.  One of the most common parental care behaviors is the facilitation of offspring feeding.  This behavior is often exhibited by insect species that also display aggregation behavior, which is an association between two or more conspecifics that persists for more than a fleeting moment.  Bed bugs, Cimex lectularius L., form aggregations with conspecifics of every life stage.  Within these aggregations, juvenile bed bugs may be associated with their mothers throughout the course of their development.  We hypothesized that this proximity between adults and juveniles would allow females (the sex most commonly responsible for parental care) to facilitate host-finding by her offspring.  To challenge this hypothesis, we evaluated the success of first instar feeding in the presence or absence of adults.  We tested the alternative hypotheses that females signal while feeding, or lay a trail back toward harborages after feeding.  In behavioral assays, nymphs in the presence of females took a blood meal more frequently than nymphs alone or in the presence of other conspecifics.  We collected and analyzed chemical compounds emitted by females during and after feeding events.  Attraction and orientation to these chemicals by nymphs was assessed in various behavioral assays.  The implications of these results for bed bug fitness are discussed, as well as the potential of our findings to lead to new ways to detect low-level populations.