Abstract A wide range of interactions between insects and their associated microbial communities have been documented, with profound implications for host characteristics such as development, biology, and behavior. While much emphasis has been placed on bacterial endosymbionts, the mutual interactions between insects and their external symbionts are often overlooked. In this study, we investigated the potential of the external microbiome to mediate survival and behavioral changes in the workers of red imported fire ants (RIFA). Using culture-based methods, the bacterial species present on the cuticle of the ants were isolated and identified. Experimental manipulation of ant exosymbionts was achieved through the treatment of workers with bacterial monocultures, antibiotics, or a combination of both. Artificial modification of ant cuticle bacterial symbionts revealed significant changes in survival rates and behavioral patterns. The removal of ants’ cuticle exosymbionts induced about 89% cumulative mortality within 10 days of treatment, significantly higher than that observed in other treatments and the control group. Similarly, artificial manipulation of ant cuticle bacterial symbionts impaired the ants’ ability to be recognized by their nestmates, as worker ants with an altered cuticle experienced a higher rejection rate compared to those with an intact external microbiome. In addition, foraging activities were affected, including the workers’ ability to kill prey, search for food, and the weight of food carried over a given duration. These results revealed that cuticular bacteria influence both survival and certain social behaviors in RIFA. Understanding the diversity and potential use of these exosymbiotic bacteria would provide insights into promising biological strategies for RIFA management.
Bamisile et al. (Fri,) studied this question.