Observation of Flower Visitors to Determine their Potential Role as Pollinators of Ixora coccinae and Ruellia simplex

Abstract

This study aimed to determine the potential pollinating agents of Ixora coccinae and Ruellia simplex at Universiti Malaysia Terengganu (UMT) campus based on the foraging activities of the flower visitors. The diurnal observations (0700 hr to 1800 hr) were conducted for a total of 144 hours and 96 hours for I. coccinae, for R. simplex respectively. The flower visitor activities (landing or hovering at the flowers) and the time spent at the flowers however were recorded for only the first 10 minutes of every hour between 0700 hr and 1000 hr for four days. A total of 383 flower visitations was recorded by 17 insect species and a bird species, the olive-backed sunbird (Cinnyris jugularis). For I. coccinae, the most common visitors were Apis cerana, Heterotrigona itama and Xylocopa confusa, in which all species were found to show only landing behaviour to forage at the flowers, and the time spent foraging at the flowers was not significantly different between the species (Kruskal-Wallis test, H = 1.323, df = 2, p = 0.055). For R. simplex, the most common visitors were A. cerana with 100% landing, and C. jugularis which recorded 80% landing and 20% hovering during their visits to the flowers. Between the two, A. cerana recorded significantly longer time spent at the flowers as compared to C. jugularis (Mann-Whitney test, U = 17.355, p < 0.001). Based on the visitation rate and feeding behaviour of the flower visitors, A. cerana, H. itama and X. confusa were the potential pollinating agents for I. coccinae while for R. simplex, A. cerana showed higher potential to be a pollinating agent as compared to C. jugularis. Therefore, this study highlighted the importance of recording the behaviour of each flower visitor to determine the relative contribution to the pollination success of the plant species visited.