Metcalfa pruinosa is an invasive planthopper that has rapidly spread across South Korea since its first detection in 2005. Long-term suppression is difficult using chemical control alone. This study developed a cocoon-based outdoor release technique for the parasitoid Neodryinus typhlocybae, a major natural enemy of M. pruinosa, and analyzed the seasonal occurrence patterns of both species while evaluating the establishment and parasitism of N. typhlocybae across multiple regions. A rain-shielded release device was designed to facilitate adult emergence and escape, resulting in emergence from more than 75% of the cocoons and the successful escape of 88.9% of the emerged adults. The optimal timing for parasitoid release was identified as mid-to-late June when 4th-instar M. pruinosa nymphs are predominant, while parasitism assessments were best conducted in mid-to-late July during the 5th-instar stage. Between 2024 and 2025, N. typhlocybae cocoons were detected in eight municipalities across five provinces. Notably, cocoon densities reached 8.2 cocoons per 20 leaves in Jangseong in 2024 and 3.2 cocoons in Asan in 2025, clearly demonstrating successful parasitism and overwintering under Korean field conditions. Cocoons also persisted at sites where releases were conducted between 2020 and 2022, without additional releases. No significant relationships were observed between cocoon density and release amount, region, or year, suggesting that host density, microclimate, and other field-level environmental factors have greater influences on parasitism outcomes. This study provides key foundational data supporting the practical implementation of N. typhlocybae for the biological control of M. pruinosa in South Korea.

Abstract
1. 서 론
2. 재료 및 방법
    2.1. 시험 곤충
    2.2. 방사통을 이용한 선녀벌레집게벌야외 방사법 개발
    2.3. 시기별 미국선녀벌레와 선녀벌레집게벌발생 밀도 조사
    2.4. 선녀벌레집게벌 기생 및 정착 여부 조사
    2.5. 통계 분석
3. 결과 및 고찰
    3.1. 방사통을 이용한 선녀벌레집게벌 야외 방사법 개발
    3.2. 시기별 미국선녀벌레와 선녀벌레집게벌발생 밀도 조사
    3.3. 선녀벌레집게벌 기생 및 정착 여부 조사
    3.4. 연구의 한계 및 제언
적 요
CRediT authorship contribution statement
Declaration of Competing Interest
사 사
REFERENCES
APPENDIX

• 선현오(국립농업과학원 농산물안전성부 해충잡초방제과) | HyunOh Sun (Pests and Weeds Control Division, Department of Agro-food Safety and Crop Protection, National Institute of Agricultural Sciences, RDA, Wanju 55365, Republic of Korea)
• 김정환(국립농업과학원 농산물안전성부 해충잡초방제과) | Jeong Hwan Kim (Pests and Weeds Control Division, Department of Agro-food Safety and Crop Protection, National Institute of Agricultural Sciences, RDA, Wanju 55365, Republic of Korea)
• 서보윤(국립농업과학원 농산물안전성부 해충잡초방제과) | BoYoon Seo (Pests and Weeds Control Division, Department of Agro-food Safety and Crop Protection, National Institute of Agricultural Sciences, RDA, Wanju 55365, Republic of Korea)
• 노현정(국립농업과학원 농산물안전성부 해충잡초방제과) | Hyeon Jung Noh (Pests and Weeds Control Division, Department of Agro-food Safety and Crop Protection, National Institute of Agricultural Sciences, RDA, Wanju 55365, Republic of Korea)
• 정다경(국립농업과학원 농산물안전성부 해충잡초방제과) | Dagyeong Jeong (Pests and Weeds Control Division, Department of Agro-food Safety and Crop Protection, National Institute of Agricultural Sciences, RDA, Wanju 55365, Republic of Korea) Corresponding author
• 박홍현(농림축산검역본부 식물검역기술개발센터) | Hong Hyun Park (Plant Quarantine Technology Center, Animal and Plant Quarantine Agency, Sejong 30110, Republic of Korea)