Does group living affect growth and survivorship of bed bugs?

Bed bugs (Cimex lectularius) live in aggregations or groups comprised of adults and nymphs of all ages. For some animals, including many insect species, living in groups provides important physiological and/or behavioral benefits such as decreased risk of predation, decreased energetic costs of movement and foraging, increased foraging efficiency, increased encounters with mates, or faster development. The adaptive benefits of living in group, if any, remain unknown for bed bugs. Our aim was to determine whether living in groups accelerates development of bed bugs nymphs. We observed three treatments of first instars from hatching to adulthood and recorded their development time in days. Treatments included solitary nymphs, grouped nymphs, and nymphs grouped with adults. Our results indicate that bed bug development is unaffected by grouping. There were no significant differences in development time among solitary, grouped, or nymphs grouped with adults. Thus, unlike some other gregarious insect species, nymphal development time in bed bugs is unaffected by social conditions. Nevertheless, the propensity of bed bug nymphs to orient to aggregation pheromones and to live in groups suggest that they might accrue other benefits from group living