Aggregation pheromones of Japanese orange fly, Bactrocera tsuneonis (Diptera: Tephritidae)

Bactrocera tsuneonis (Diptera: Tephritidae) is an important quarantine pest. It is oligophagous, feeding exclusively on citrus fruits. However, no effective and specific attractant for monitoring and controlling this pest has yet been developed. Although insect pheromones are usually species-specific and safe attractants, little is known about the components and functions of B. tsuneonis pheromones. We analyzed the composition of pheromone extracts from B. tsuneonis, and demonstrated their biological functions using laboratory bioassays and field-trapping trials.

Nine compounds were identified in hexane extracts and headspace collections from B. tsuneonis, and six compounds in the headspace collections elicited electrophysiological responses in both male and female flies: nonanal, N-(3-methylbutyl) acetamide, decanal, 1,2-octanediol, hexadecanol and ethyl (E)-9-hexadecenoate. A Y-tube bioassay showed that N-(3-methylbutyl) acetamide, 1,2-octanediol and decanal were significantly more attractive to female and male B. tsuneonis than to controls (P < 0.05). Field-trapping trials confirmed the attractiveness of 1,2-octanediol and N-(3-methylbutyl) acetamide to females and males from wild populations, but their mixture (at a ratio of 1:1) did not exhibit attraction toward this pest.

To the best of our knowledge, this is the first report that N-(3-methylbutyl) acetamide and 1,2-octanediol are aggregation pheromones of B. tsuneonis, and these two compounds can be used to develop an attractant for monitoring and controlling this pest. © 2025 Society of Chemical Industry.