Influence of temperature on the reproductive success of a fig wasp and its host plant

Abstract

Ambient temperatures influence many aspects of insect behavior and reproduction, and limit their distribution and abundance. Small, delicate insects such as the fig wasps (Agaonidae) that pollinate fig trees rapidly succumb to heat stress when outside figs. We compared survivorship and reproductive success of the fig wasp Kradibia tentacularis pollinator of the Asian fig tree Ficus montana in three glasshouses maintained at different temperatures during the brief period when foundress females are laying their eggs after their entry into figs (means of 17, 21 and 27°C, respectively). This temperature range had no significant effect on speed of foundress death, or their likelihood of re-emergence. Similarly, fig wasp offspring production were unaffected by temperatures at the time of oviposition in male figs, as was seed production in female figs, although the proportion of failed galls changed marginally. The range of temperatures to which the fig wasps were exposed reflected conditions under a tropical forest canopy and their general lack of responsiveness suggests that the relatively buffered environment within their host figs means that only extreme temperature conditions will influence them once they have entered the plant.