Identification of Sex Pheromone Components of Korean Dioryctria abietella (Lepidoptera: Pyralidae) Population and Synergism of Pheromone and Pine Cone Volatile Blends

Professor  Il-Kwon Park (Department of Agriculture, Forestry and Bioresources)

(Lee, S. C., Lee, J. W., Lee, D. H., Huh, M. J., Nam, I., Park, J. H., Jung, M., & Park, I. K. (2022). Identification of Sex Pheromone Components of Korean Dioryctria abietella (Lepidoptera: Pyralidae) Population and Synergism of Pheromone and Pine Cone Volatile Blends. Journal of Economic Entomology, DOI:  https://doi.org/10.1093/jee/toab227)

Spruce cone worm, Dioryctria abietella is a major insect pest of Korean pine (Pinus koraiensis) in Korea. This pest mainly feeds on the flesh of the Korean pine cone and significantly reduces the production of Korean pine nuts. This has decreased the income of pine nut producers because Korean pine nuts are a popular health food in Korea. Spruce cone worm spends most of its larval stage inside the pine cone, so it is essential to monitor the exact flight phenology of D. abietella adults to provide information for the best timing of insecticide application. Pheromone has been considered as one of the most effective tools for the monitoring of insect pests. In this study, female pheromone gland extracts of D. abietella were analyzed, and field attraction tests of candidate pheromone components were conducted to develop an efficient monitoring method for D. abietella.

Fig 1. Chromatograms of D. abietella female gland extracts (a), ionization spectra of female extract and synthetic 9Z,11E-14:OAc (b), and female extract and synthetic C25 pentaene (c).

Gas chromatography-mass spectrometer analyses of pheromone gland extracts from D. abietella female adults revealed 9Z,11E-14:OAc and C25 pentaene to which antennae of male D. abietella showed the strong electrophysiological response [Fig. 1(a)]. The ratio of 9Z,11E-14:OAc to C25 pentaene from the pheromone gland extracts was 1 : 23. The major electron ionization (EI) ions of 9Z,11E-14:OAc and C25 pentaene were identical to those of synthetic 9Z,11E-14:OAc and synthetic C25 pentaene.

Fig. 2. Mean number of Dioryctria abietella captured in delta traps baited with different ratios of 9Z,11E-14:OAc and C25 pentaene. Ac = 9Z,11E-14:OAc, C25 = C25 pentaene.

In field attraction test, significantly more males were attracted to traps baited with 100 : 1,000 μg, 100 : 2,000 μg, and 100 : 3,000 μg of 9Z,11E-14:OAc and C25 pentaene compared with traps baited with other ratios of 9Z,11E-14:OAc and C25 pentaene. This study showed that pheromone traps baited with 100 : 1,000 ~ 100 : 3,000 ug of 9Z,11E-14:OAc to C25 pentaene will be useful for the exact monitoring and management of D. abietella in Pinus koraiensis forests.