The National Institute of Forest Science (NiFoS), under the Korea Forest Service, has identified a natural enemy of Orthaga olivacea for the first time in Korea. This species is a major pest that damages red machilus (Machilus thunbergia).

Red machilus (Machilus thunbergia), an evergreen broadleaf species, is widely distributed along the southern coast and on islands of Korea and is valued for both its landscape and industrial uses. However, damage caused by larvae of O. olivacea—including reduced growth and aesthetic deterioration—has been widely reported.

Researchers from NiFoS and the Jeollanam-do Forest Environment Research Institute conducted a study on overwintering cocoons of O. olivacea collected in Haenam, Jeollanam-do. The study found that the parasitic wasp Phanerotoma flava is a natural enemy of this pest. This is the first report of P. flava using O. olivacea as a host.

The parasitism rate ranged from 12.5% to 28.3%, and more than 75% of the individuals were identified as female, indicating high reproductive potential. In addition, the wasp emerged 3 to 10 days later than its host, coinciding with the host’s oviposition period, suggesting its potential for suppressing O. olivacea populations.

The study improved the accuracy of species identification and overall reliability by combining morphological analysis with DNA barcoding (COI gene analysis). The findings were published online in March 2026 in the international journal Journal of Asia-Pacific Entomology.

Junheon Kim, a researcher at the Forest Pest and Disease Division of NiFoS, stated, “This study represents the first identification of a natural enemy of O. olivacea in Korea and provides a basis for the development of eco-friendly management strategies using biological control. We will continue follow-up studies to support field application.”