Floral development and potential pollinators of Syzygium myhendrae (Bedd. ex Brandis) Gamble, a wild endemic tree of the Southern Western Ghats, India

Abstract

Syzygium myhendrae, is a semi-evergreen, endemic and endangered tree species of the Southern Western Ghats, India which exhibits bi-annual mode of flowering and fruiting behaviour. This research is specifically aimed to observe the sequence of morphological processes occurring during floral development and to identify the potential pollinators from the different floral visitors. These aims are achieved by examining the individual trees of candidate species during their flowering season. Sticky traps, bee bowls, sweep nets and pan traps were used to capture floral visitors at the anthesis stage. Visitation frequency and visitor activity index were calculated to distinguish effective pollinators from visitor insects. The results showed nine stages in flower development starting from flower bud emergence to fruit ripening, which took 6-9 weeks. Nine species of insects were recorded as visitors. Honey bees (Apis cerana, ApisMdorsata and Tetragonula iridipennis), butterflies (Hypolimnas misippus,pachilopta pandiana), wasp species, beetle species, fly species were exclusively visiting the flowers of the candidate species. Among the honey bees, Apis dorsata showed high visitation frequency (0.40±0.01) followed by Apis cerana (0.31±0.02) and Tetragonula iridipennis (052±0.02). As per the visitation frequency, it can be concluded that Apis dorsata was the most frequent and effective pollinator.