title: Effects of natural and synthetic alarm pheromone and individual pheromone components on foraging behavior of the giant Asian honey bee, Apis dorsata.
abstract: Social pollinators such as honey bees face attacks from predators not only at the nest, but also during foraging. Pollinating honey bees can therefore release alarm pheromones that deter conspecifics from visiting dangerous inflorescences. However, the effect of alarm pheromone and its chemical components upon bee avoidance of dangerous food sources remains unclear. We tested the responses of giant honey bee foragers, Apis dorsata, presented with alarm pheromone at a floral array. Foragers investigated the inflorescence with natural alarm pheromone, but 3.3-fold more foragers preferred to land on the 'safe' inflorescence without alarm pheromone. Using gas chromatography-mass spectrometry analysis, we identified eight chemical components in the alarm pheromone, of which three components (1-octanol, decanal and gamma-octanoic lactone) have not previously been reported in this species. We bioassayed six major compounds and found that a synthetic mixture of these compounds elicited behaviors statistically indistinguishable from responses to natural alarm pheromone. By testing each compound separately, we show that gamma-octanoic lactone, isopentyl acetate and (E)-2-decen-1-yl acetate are active compounds that elicit significant alarm responses. Gamma-octanoic lactone elicited the strongest response to a single compound and has not been previously reported in honey bee alarm pheromone. Isopentyl acetate is widely found in the alarm pheromones of sympatric Asian honey bee species, and thus alarmed A. dorsata foragers may produce information useful for conspecifics and heterospecifics, thereby broadening the effects of alarm information on plant pollination.
authors.affiliation: Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan Province 650223, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan Province 650223, China.
authors.forename: Zhengwei
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan Province 650223, China Eastern Bee Research Institute, Yunnan Agricultural University, Kunming 650201, China kentan@xtbg.ac.cn.
authors.forename: Ken
authors.initials: K
authors.lastname: Tan
authors.affiliation: Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan Province 650223, China.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Qu
authors.affiliation: Division of Biological Sciences, Section of Ecology, Behavior and Evolution, University of California, San Diego, La Jolla, CA 92093, USA.
authors.forename: James C
authors.initials: JC
authors.lastname: Nieh
mesh_terms: D000819:Animal Communication; D000818:Animals; D001070:Appetitive Behavior / Q000502:physiology*; D001516:Bees / Q000502:physiology*; D002681:China; D008401:Gas Chromatography-Mass Spectrometry; D010675:Pheromones / Q000737:chemistry / Q000502:physiology*; D006109:Poaceae; D054817:Pollination; D012919:Social Behavior
chemical_list: D010675:Pheromones
keywords: Alarm pheromone; Foraging; Honey bee; Information flow; Predator attack