1-octadecene, A Female Produced Aggregation Pheromone of the Coffee White Stem Borer (Xylotrechus quadripes)

• Published in: Horticulturae 2023-01, Vol.9 (2), p.173
• Main Authors: Mangalgikar, Prashant, Madhura Bhanu, Karumuru Raja, Belavadi, Vasuki, P K, Vinod Kumar, Muniyappa, Chandrashekharaiah, Ammagarahalli, Byrappa
• Format: Article
• Language: English
• Subjects: Agglomeration; Aggregation pheromone; Air entrainment; Antennae; Beetles; Borers; Borers (Insects); Chromatography; Coffee; Coleoptera; Control; Electroantennograms; Entrainment; entrainment method; Environmental aspects; Females; Gas chromatography; Hydrocarbons; Insect pests; Insects; Laboratories; live-beetle trap; Males; Mass spectrometry; Mass spectroscopy; pheromone blend; Pheromone traps; Pheromones; Physiological aspects; Scientific imaging; Sensors; Sexual behavior; volatile; Volatiles; Xylotrechus quadripes
• ISSN: 2311-7524; 2311-7524
• DOI: 10.3390/horticulturae9020173

Coffee white stem borer, Xylotrechus quadripes is a serious insect pest of coffee across the world. Pheromone traps baited with male produced 2-hydroxy- 3-decanone (2H3D) attracted females, and also males. Interestingly, a pair of males and females in a cage attracted more beetles compared to 2H3D traps. We hypothesized volatiles emitted from females are perceived by males. Volatiles from females were collected through the air entrainment method and identified 1-octadecene by using gas chromatography coupled with mass spectrometry. Release of 1-octadecene was female specific, however, both male and female antennae elicited responses in chromatography-electroantennography. Electroantennogram responses were dose-dependent in both sexes and were higher in the antennae of females. Combination of male pheromone component 2H3D, and female produced 1-octadecene at 1:2 ratio increased both male (0.69 ± 0.13; mean ± SEM in -mV) and female (0.98 ± 0.20) antennal responses. Responses to constant doses of 2H3D and increasing doses of 1-octadecene (1:4, 1:6, 1:8, 1:10) were not different from male pheromone alone. Beetle captures to male pheromone alone at 3 different doses (75, 150 and 300 mg) were not significantly different from a pair of live beetle traps. A blend of 2H3D and 1-octadecene at 1:2 ratio trapped more beetles (3.50 ± 0.65; mean ± SEM) over 2H3D alone (2.00 ± 0.82), overall, our experiments suggest 1-octadecene is an aggregation pheromone. Our results support the hypothesis that males use 1-octadecene in mate finding, and potential to use it for monitoring and mass trapping.