Identification and Behavioral Assays of Alarm Pheromone in the Vetch Aphid Megoura viciae

• Published in: Journal of chemical ecology Vol. 47; no. 8-9; pp. 740 - 746
• Main Authors: Song, Xuan, Qin, Yao-Guo, Yin, Yue, Li, Zheng-Xi
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2021; Springer Nature B.V
• Subjects: Agriculture; Alarm pheromone; Animals; Aphids - chemistry; Aphids - growth & development; Aphids - physiology; Behavior, Animal - drug effects; Bicyclic Monoterpenes - isolation & purification; Bicyclic Monoterpenes - pharmacology; Biochemistry; Biological Microscopy; Biomedical and Life Sciences; Camphene; Chemical ecology; Developmental stages; Ecology; Entomology; Farnesene; Gas chromatography; Gas Chromatography-Mass Spectrometry; Host plants; Insect Control - methods; Insects; Life Cycle Stages; Life Sciences; Limonene; Mass spectrometry; Mass spectroscopy; Megoura viciae; Monoterpenes; Pests; Pheromones; Pheromones - analysis; Pheromones - chemistry; Pheromones - pharmacology; Pisum sativum - chemistry; Pisum sativum - metabolism; Pisum sativum - parasitology; Repellency; Sabinene; Sesquiterpenes - isolation & purification; Sesquiterpenes - pharmacology; Squalene; Terpenes; Terpenes - analysis; Terpenes - chemistry; Terpenes - pharmacology; Terpineol; α-Pinene; Behavioral assay; Alarm pheromone; Terpenoids; Mixture; Megoura viciae
• ISSN: 0098-0331; 1573-1561
• DOI: 10.1007/s10886-021-01297-4

Aphids are destructive pests, and alarm pheromones play a key role in their chemical ecology. Here, we conducted a detailed analysis of terpenoids in the vetch aphid, Megoura viciae , and its host plant Pisum sativum using gas chromatography/mass spectrometry. Four major components, (-)-β-pinene (49.74%), ( E )-β-farnesene (32.64%), (-)-α-pinene (9.42%) and ( +)-limonene (5.24%), along with trace amounts of ( +)-sabinene, camphene and α-terpineol) (3.14%) were found in the aphid. In contrast, few terpenoids were found in the host plant, consisting mainly of squalene (66.13%) and its analog 2,3-epoxysqualene (31.59%). Quantitative analysis of the four major terpenes in different developmental stages of the aphid showed that amounts of the monoterpenes increased with increasing stage, while the sesquiterpene amount peaked in the 3 rd instar. (-)-β-Pinene was the most abundant terpene at all developmental stages. Behavioral assays using a three-compartment olfactometer revealed that the repellency of single compounds varied in a concentration-dependent manner, but two mixtures [(-)-α-pinene: (-)-β-pinene: ( E )-β-farnesene: ( +)-limonene = 1:44.4:6.5:2.2 or 1:18.4:1.3:0.8], were repellent at all concentrations tested. Our results suggest that (-)-α-pinene and (-)-β-pinene are the major active components of the alarm pheromone of M. viciae , but that mixtures play a key role in the alarm response. Our study contributes to the understanding of the chemical ecology of aphids and may help design new control strategies against this aphid pest. Graphical abstract