ABSTRACT Increasing group size has been proposed as a key factor in mitigating the negative effects of stress in eusocial insects. In general, previous studies suggest that larger groups confer benefits by increasing the frequency of behaviors performed by individuals. In termites, however, such studies have rarely considered the social context, such as the presence of different castes. Here, we investigated how group size and the social context (presence of soldiers) affect per‐capita behavioral frequency in Nasutitermes corniger (Termitidae: Nasutitermitinae). We examined the behaviors of nasute termite groups of varying sizes, composed either exclusively of workers or of workers plus soldiers. In general, per‐capita behavioral frequency decreased with increasing group sizes; however, this effect was higher in groups composed only of workers than in groups that included soldiers. When behaviors were analyzed separately, only per‐capita antennation frequency was significantly affected by both group size and the presence of soldiers. Per‐capita grooming frequency was significantly affected solely by group size, whereas per‐capita frequencies of trophallaxis and vibratory movements were not affected by either group size or the presence of soldiers. These results provide new perspectives into how social facilitation shapes termite behaviors and highlight the importance of social context in buffering stress within nasute termite colonies.
Watanabe et al. (Mon,) studied this question.