소나무재선충병은 1988년 부산 금정산에서 처음 발생하여 2017년 4월 기준 109시ㆍ군ㆍ구에서 99만본 이상 발생하였다. 소나무재선충 방제방법 중 가장 효과적인 방법은 나무주사로 약제 단가가 저렴해져 처리 면적은 점차 확대되고 있으나, 그 시기가 12월~2월로 극히 제한적이어서 처리시기 확대를 위해 10월 말부터 5월 중순까지 아바멕틴 유제와 에마멕틴벤조에이트 유제를 월 1회 나무주사하여 그 효과를 검정하였다. 그 결과, 10월 말~1월까지는 두 약제 모두 100% 방제효과를 보였고, 아바멕틴 유제는 2월(93.3%), 3월(86.7%), 4월(83.3%), 5월(80%) 방제효과를 나타내었다. 반면에 에마멕틴 벤조에이트 유제는 2월(100%), 3월(96.7%), 4월(96.7%), 5월(50%)로 4월까지 효과가 뛰어 났으나 5월에 급격히 방제가가 떨어졌다. 2월~5월까지 나무주사 후 약제 잔류량을 분석한 결과 아바멕틴 유제가 에마멕틴벤조에이트 유제 보다 약제 잔류량이 많았고 두 약제 모두 처리 시기가 늦을수록 약제 잔류량도 적게 나타났다. 각 시기별로 나무주사한 가지의 일부를 채취하여 소나무재선충을 접종한 결과 처리시기가 늦을수록 소나무재선충 증식량이 증가하는 경향을 보였다. 또한 처리방법을 현행방법과 주입병을 이용하여 각각 2월에 나무주사한 결과, 두 방법 모두 소나무재선충 예방효과, 약제 잔류량, 소나무재선충 증식량에는 차이가 없었다.

Various insect pest damage agricultural crops and forest. Several control strategies have been tried against these pests. Using chemical pesticides is one of the major control strategies. However, in recent years, eco-friendly control measures have received a big attention. Entomogenous nematodes are best known as potential biocontrol agent which are promising alternatives of chemical pesticides. During the survey of insect-parasitic nematodes as well as their parasitism in Korea, three new species, Parasitylenchus cyrtogenii n. sp., Parasitylenchus oscavus n. sp., Bathymermis sancheongensis n. sp. and seven other new records for the Korean nematode and nematomorpha fauna were identified, which are: Howardula phyllotretae, Parasitaphelenchus uncinatus, Hexamermis albicans, Hexamermis sp., Heterorhabditidoides chongmingensis, Pristionchus pacificus, and Spinochordodea tellini, respectively. Parasitism of nematodes ranged from 0.7 to 87.5%. The highest parasitism was recorded in P. cyrtogenii n. sp isolated from Cyrtogenius brevior as 87.5%, however the lowest parasitism found in Hexamermis sp. isolated from Oxya chinensis as 0.7%.

Parasitism of horsehair worm in mantids were investigated for two years, from 2012 and 2013. The mantids were collected from forty-nine sites from August to November. Twenty-one sites (42.9%) of the collected mantids were parasitized by horsehair worms. C. japonensis was recorded from T. angustipennis, T. aridifolia and C. fukuii. The C. japonensis parasitism of T. angustipennis and T. aridifolia were 27.0% and 10.7%, respectively. The infested number of C. japonensis was 1-9 per 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, abdomen length and digestive system of host. However, egg possession of host was different, unparasitized T. angustipennis and T. aridifolia had more eggs (63.7%) than parasitized ones (2.6%). C. japonensis was parasitized as immature stage in late Aug. immature and adult stage in early Sept. and only adult in late Oct. Parasitism was the highest in late Sept.

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%).

Amur silver grass, Miscanthus sacchariflorus is one of the promising biofuel crops. A damage of noctuid pest, Leucapamea askoldis was firstly observed from Amur silver grass in Hwasun silver grass plantation during the survey of insect pests of Amur silver grass in Iksan, Hwasun, and Sancheong plantation areas in Korea. The host of L. askoldis was not known yet in Korea. Thus, M. sacchariflorus was the first known host in Korea. The L. askoldis damage was observed as larval feeding on newly grown shoots of M. sacchariflorus close to soil surface from early April to early May in 2013. Investigated larval density was 1.6 ± 1.1 per m2 on April 4 and damage rate of shoots was 0.8% ± 0.4 per hundred plants on May 4, 2013. The larvae bore into shoots of M. sacchariflorus and then feed inside of plant. The damaged shoots are easily pulled out and distinguished by the boring hole on the shoots.