Honey Bee Foraging Decisions Influenced by Pear Volatiles

• Published in: Agriculture
• Main Authors: Wenting Su, Weihua Ma, Qi Zhang, Xiao Hu, Guiling Ding, Yusuo Jiang, Jiaxing Huang
• Format: Article
• Language: English
• Published: MDPI AG 2022-07-01
• Subjects: pear; honey bee; foraging behavior; flower volatiles; GC–MS; GC–EAD
• Online Access: https://www.mdpi.com/2077-0472/12/8/1074

The interactions between plants and pollinators are complex. Flower volatiles as special olfactory cues could influence the foraging choices of pollinators. Here, we conducted bioassays to evaluate the role of flower volatiles on the attraction of honey bees (native <i>Apis cerana</i> and exotic <i>Apis mellifera</i>) to pears (native <i>Pyrus bretschneideri</i> and exotic <i>Pyrus communis</i>). Chemical and electrophysiological approaches were used to determine flower volatiles and evaluate the antennal responses of honey bees to volatiles from pear flowers. Bioassays demonstrated that flower volatiles were crucial for the attraction of honey bees to pear flowers; honey bees preferred to forage on <i>P. communis</i> flowers (<i>p</i> > 0.05), with approximately 64.37 ± 0.02% (<i>A. mellifera</i>) and 62.10 ± 0.02% (<i>A. cerana</i>) foraging on <i>P. communis</i>. Flowers of <i>P. communis</i> and <i>P. bretschneideri</i> yielded 27 and 31 compounds, respectively, with 17 of them being common. Honey bee antennae responded to 16 chemicals, including 5 contained in both pear species: 1-nonanol, linalool, methyl 2-hydroxy-3-methylpentanoate, methyl L-isoleucinate, and α-farnesene. In addition, there were 8 electrophysiologically active compounds in <i>P. bretschneideri</i>: methyl L-valine ester, benzaldehyde, 6-methyl-5-hepten-2-one, isophorone, 2-methyl octane, longicyclene, longifolene, and caryophyllene; and 3 electrophysiologically active compounds in <i>P. communis</i>: β-ocimene, 4-oxoisophorone and lilac alcohol D. In conclusion, our study demonstrated the significant impact of pear flower volatiles on honey bee foraging choices. This knowledge provides a basis for the selection of honey bees for pear pollination and lays a foundation for further study of the chemical communication of pear attractiveness to honey bees.