Wasp emergence from the figs of Ficus sur : characteristics and predation by ants

In contrast to the well-documented biology of fig wasps when they are within their figs, little is known about the behaviour of fig wasps once they are outside. After mating is completed, exit of adult female fig wasps from their natal figs is usually aided by the flightless males that chew a communal exit hole through the fig wall. We recognised three sub-phases in the exit of the pollinating fig wasp Ceratosolen capensis Grandi 1955 from the figs of Ficus sur , a species where male wasps do not re-enter figs after they have exited. The presence of ants was correlated with fig wasp exit dynamics, and as males generally exited first, they were 10 times more likely to be captured by the predatory ants that are routinely waiting on the fig surface. The males also occupied more ants, for a longer duration, than female fig wasps. As a result, predation on males seemed to reduce predation on the females. This would be advantageous for males since females are often siblings and/or could have previously mated with the males. Once ant numbers on a fig increase beyond 15, however, the proportion of females captured seemed to climb steeply, indicating a possible breakdown of protection by males at high ant densities. We conclude by examining the role of ants in the evolutionary dynamics of figs and fig wasps, and argue that the plant-pollinator mutualism needs to be considered within the broader context of the complex interactions taking place on the plants.