Effect of trap color, pheromone and kairomone release rates, and <i>α</i> -pinene and limonene enantiomers on the capture of <i>Monochamus saltuarius</i> Gebler (Coleoptera: Cerambycidae)

Monochamus saltuarius (Gebler) (Coleoptera: Cerambycidae) is a significant forest pest that spreads pine wood nematodes [Bursaphelenchus xylophilus (Steiner & Bührer) Nickle) (Aphelehncida: Parasitaphelenchidae)] across northern Eurasia, including South Korea. The Korea Forest Service recommends the use of pheromone traps to monitor the spread of this insect vector. However, to improve the accuracy of occurrence monitoring and enhance control through mass trapping, it is necessary to increase the capture efficiency of pheromone traps. In this study, we evaluated various pheromone trap conditions to improve the attraction efficiency of M. saltuarius by modifying trap color, enantiomers, and the release rates of pheromone and kairomones. Among the 6 tested colors (black, red, green, blue, yellow, and white), M. saltuarius exhibited the most potent attraction to black traps. In enantiomer preference tests, M. saltuarius showed no significant difference in response to the enantiomers of α-pinene and limonene. To evaluate the effects of pheromone and kairomone release rates on the capture of M. saltuarius, traps were baited with varying release rates of each compound-monochamol (5.7 to 28.5 mg/day), ethanol (15.9 to 79.5 mg/day), α-pinene (18.1 to 90.5 mg/day), and ipsenol (5.9 to 29.5 mg/day)-and the number of captures was compared. The optimal release rates for monochamol, ethanol, α-pinene, and ipsenol were 22.8, 15.9, 18.1, and 23.6 mg/day, respectively. Traps baited with the optimal release rates of each compound captured M. saltuarius 49.7% more effectively than those baited with the minimum release rates.