关键词: 腊梅, 访花行为, 飞行行为, 访花频率

Abstract

Variable insect behaviors may result in different flower visiting frequencies, which may result in diverse impacts on plant pollination. Although flies, hoverflies, and Italian bees (Apis mellifera ligustica) were the most common visitors of Chimonanthus praecox, these insect groups had disparate visiting behaviors. Flies traveled quickly, and crawled or jumped between flowers. Italian bees also flew quickly or occasionally crawled between flowers. In contrast, hoverflies generally spent a majority of time foraging on a given flower. Based on the average foraging time and inter-floral flight time, one Italian bee could visit 4.57 flowers per minute, whereas individual bees and hoverflies could visit 2.65 and 0.53 flowers on average, respectively. After incorporating the total number of individuals for each insect group, we extrapolated the visiting rates of Italian bees, flies and hoverflies as 498.19, 1,089.74 and 99.78 flowers per minute, respectively. Flies and Italian bees had higher pollination effectiveness (number of pollinated flowers by the same number of visitors in a given time interval under the same condition), with estimates of 93% and 100% (n = 30), respectively, while only 13% (n = 30) for hoverflies. If we consider the pollen load ability and pollination effectiveness for Italian bees and flies, visiting rate may be the main limiting factor for their potential in pollinating flowers. Thus following these conclusions, flies are the major pollinators of C. praecox, followed by Italian bees (pollination role was limited by their low number) and hoverflies (limited by their foraging and hovering behaviors and lower pollination effectiveness).

Key words: Chimonanthus praecox, visiting behavior, flying behavior, visiting frequency