Abstract:

There are about 800 species of fig trees in the world, which are mainly distributed in tropics, some species extend to subtropics. Fig trees rely on agaonid fig wasps to pollinate and are also exploited by some non-pollinating fig wasps. Fig wasps depend heavily on temperature who can only maintain normal physiological functions within a certain temperature range that is more sensitive than fig trees. Temperature directly affects the fig wasp’s abundance and interspecific relationships. However, lack of research leaves a knowledge gap in our understanding of how fig wasp temperature tolerance affects the coexistence of wasps in fig. We conducted the experiment of temperature tolerance on six species of fig wasps from monecious Ficus altissima and F. racemosa, and dioecious F. semicordata in Xishuangbanna. Our results show that high temperature tolerance of all pollinating fig wasps was low, while the tolerance of Ceratosolen gravelyi on F. semicordata to low temperature was enhanced. When looking at fig wasp community composition on F. racemosa, the pollinating fig wasp are dominant species, but the population was decreased significantly in low temperature seasons in Xishuangbanna. While non-pollinating fig wasps showed the opposite pattern, which maintained high abundances during the cool-foggy season with low temperature due to greater temperature tolerances. On F. semicordata, non-pollinating fig wasps Sycoscapter trifemmensis had stronger temperature tolerance than Philotrypesis dunia so that the former had competitive advantage and large population. Differences in temperature tolerance of fig wasps plays an important role in species distribution, maintaining interspecific relationships and coexistence. Our results provide scientific evidence for understanding fig wasp coexistence.

Key words: fig wasp, physiology, temperature tolerance, community dynamic