Meeting Abstract
The frequency and nature of social interactions during the early stages of a disease outbreak can determine the magnitude of the potentially ensuing epidemic. Two factors which may have a strong influence over these interactions are (1) the composition of behavioral phenotypes among the susceptible population and (2) the behavioral traits of the index case (i.e. ‘patient zero’). Unfortunately, these two factors are rarely examined in unison. Here, we test whether the personality composition of social groups can explain the horizontal transmission dynamics of a cuticular bacterium, Pantoea sp., in the social spider Stegodyphus dumicola. We topically exposed focal spiders of known behavioral types (i.e., bold or shy personality types) with GFP-transformed Pantoea and allowed them to interact with groups of 10 susceptible individuals with no previous experience with the transformed bacterium. We estimated the bacterial transmission that occurred in groups composed of either all shy spiders, 10% bold spiders, or 40% bold spiders. We found that colonies with 40% bold spiders experienced over twice the incidence of transmission compared to colonies with just 10% bold individuals after only 24 h of interaction. Colonies containing all shy spiders experienced an intermediate degree of transmission. Interestingly, we did not detect an effect of the traits of the index case on these trends. Thus, perhaps the phenotypic composition of the susceptible population can have a stronger influence over the magnitude of early, rapid transmission events compared to the behavioral traits of the index case.
