C. Kerdelhue et Jy. Rasplus, NON-POLLINATING AFROTROPICAL FIG WASPS AFFECT THE FIG-POLLINATOR MUTUALISM IN FICUS WITHIN THE SUBGENUS SYCOMORUS, Oikos, 75(1), 1996, pp. 3-14
Ficus are species-specifically pollinated by chalcidoid wasps (Agaonid
ae), and the fig tree-fig pollinator mutualism has long been studied.
A diversity of other chalcids, both gall-makers or parasitoids, co-occ
ur in each monoecious Ficus species, and use the fig resource by devel
oping in ovaries that they transform into galls. The oviposition seque
nce and impact on the mutualism of these non-pollinating fig wasps wer
e studied on two Ficus species of the subgenus Sycomorus in the Ivory
Coast. Field observations, fig measurements and counts of wasps and se
eds from mature figs were conducted. Four groups of fig wasp species o
viposit in the ovaries at different stages of syconial development, an
d were demonstrated to lay eggs in the internal ovary layers; the most
external flowers seem to be protected against oviposition and thus de
velop into seeds. Non-pollinating wasp species, by parasitizing pollin
ator larvae or by competing for oviposition sites, have a significant
negative impact on the pollinator population and dynamics, and thereby
on Ficus male function (i.e. pollen dispersal). In contrast, but for
one species, they do not affect the seed production, that is, the tree
female function.