Horsehair worm parasitism of mantids was investigated for two years, 2012 and 2013. The mantids were collected from forty-nine sites from August to November. Mantids collected from twenty-one sites (42.9%) including Amur silver grass plantation at Samjang-myeon in Sancheong, Gyeongnam province were parasitized by horsehair worms.
C. japonensis was recorded from T. angustipennis and T. aridifolia and C. fukuii, a newly recorded species in Korea, was isolated from T. aridifolia.
C. japonensis was found from T. angustipennis and T. aridifolia collected from Gyeongnam province (Jinju, Sancheong, Sacheon, Uiryeong, Hapcheon, and Goseong) and Sangju, Gyeongsbuk province. C. fukuii was isolated from T. aridifolia collected from Gunwi, Gyeongbuk province and Yangpyeong, Gyeonggi province.
The C. japonensis parasitism of T. angustipennis and T. aridifolia was 27.0% and 10.7%, respectively. The number of C. japonensis in a host was from one to nine, but most was one from a host. The body length of C. japonensis showed tendency to decrease with number of parasites, but not significantly different. Horsehair worms did not affect body and abdomen length and digestive system of host. However, egg possession of host was different, that is, unparasitized T. angustipennis and T. aridifolia. had more eggs (63.7%) than parasitized ones
(2.6%).

• Eun Ju You(SM biovisionTM)
• Sang Myeong Lee(SM biovisionTM)
• Young Hak Jung(Division of Applied Life Science (BK21), Gyeongsang National University)
• Jin Young Choi(Division of Applied Life Science (BK21), Gyeongsang National University)
• Ho Yul Choo(Department of Applied Biology, Gyeongsang National University)