Pollinator and non-polinator fig wasp relationship in syconia of Ficus exasperata

摘要

Ficus species are pollinated only by species specific wasps of the subfamily Agaoninae (Hymenoptera: Agaonidae). Hence, figs have an intimate relationship with its pollinating fig wasps that oviposit within fig ovaries and the resulting larvae feed on the developing seeds. Figs are also associated with non-pollinator wasps of the family Agaonidae that either oviposit within fig ovaries thereby resulting in galls, or parasitize the larvae of pollinator wasps thereby affecting the fig-pollinator relationship. The present study identifies the fig wasps associated with the dioecious fig, Ficus exasperata, a common fig in Sri Lanka and investigates the relationship between the pollinator and non-pollinator wasps. During the fig off season in December 2007, 50 syconia collected from a single hermaphroditic tree of F. exasperata located in the Peradeniya University Park were subjected to this study. From these figs emerged the pollinator wasp Karadibia gestroi and the non-pollinator parasitoid wasp Philotrypesis quadrisetosa. Emergent pollinator fig wasps were the most abundant with a mean of 213.50 wasps per fig in comparison to the non-pollinator parasitoid wasps that ranged from 0-67 per fig. There was no significant relationship (r = -0.168) between the numbers of pollinator and non-pollinator wasps that emerged from a fig. The sex ratio of the pollinator wasp, K. gestroi that emerged from figs was strongly female biased (0.20) inferring that the offsprings are from a single or few mothers. Keywords: dioecious fig; syconia; parasitoid; parasitism DOI: 10.4038/cjsbs.v38i2.1860 Cey. J. Sci. (Bio. Sci.) 38 (2): 67-73, 2009