Pathogenicity of Korean Entomopathogenic Nematodes (Steinermematidae and Heterorhabditidae) against Local Agricultural and Forest Insect Pests

한국산 곤충병원성 선충 (Steinernematidae와 Heterorhabditidae)의 지역농림해충에 대한 병원성

Pathogenicity of Korean entomopathogenic nematodes against local insect pests was different depending on strains or target-insect pests. Mortalities of diamondback moth, Plutella xylostella larvae were 51.8%, 77.8%, 96.3% or 100% in Hanrim Steinernema sp. and 50.0%, 74.1%, 96.3% or 98.1% in Hamyang Heterorhabditis sp. on filter paper when larvae were exposed to 3, 6, 12, or 24 nematodes per larva. Mortalities of them on kale leaves at the same concentration were 44.4%, 63.0%, 76.1%, or 94.5% in Hanrim Steinernema sp. and 79.7%, 81.6%, 94.4%, or 100% in Hamyang Heterorhabditis sp., respectively. In field test, control value of Hanrim Steinernema sp. was 72.0% and that of Hamyang Heterorhabditis sp. was 84.1% in 14 days when 300,000 nematodes were sprayed to each plot ($13.27\m^2$). Although mortalities of rice stem borer, Chilo suppressalis larvae showed no difference at high concentration, Hamyang Heterorhabditis sp. (47.3~100%) was more effective than Hanrim Steinernema sp. (34.3~83.3%) at low concentration, 50~200 nematodes/ml. When chestnut curculio, Curculio sikkimensis larvae were treated with Sancheong Steinernema sp. and Hamyang Heterorhabditis sp., respectively. When pellucid zygaenid, Pryeria sinica larvae were exposed to nematodes, Pocheon Steinernema sp. was effective ranging from 96.7% to 100% but mortalities of them were 63.3~76.7% in Dongrae Steinernema sp..

우리나라에서 분리된 곤충병원성선충들의 지역농림해충에 대한 병원성은 선충의 종류와 대상해충에 따라 차이가 있었다. 한림산 Steinemema sp.와 함양산 Heterorhabditis sp.를 배추좀나방유충 한마리당 3, 6, 12, 24마리 처리한 결과, 여과지상에서 각각 51.8%, 77.8%, 96.3%, 100%와 50.0%, 74.1%, 96.3%, 98.1%의 치사율을 얻었고, 케일잎에서는 44.4%, 63.0%, 76.1%, 94.5%와 79.7%, 81.6%, 94.4%, 100%의 치사율을 얻었다. 구당 (13,27$m^2$)300,000마리 농도로 배추밭에 처리한 결과 14일후 한림산 Stemermema sp. 는 72.0%, 함양산 Heterorhabditis sp. 는 84.1%의 방제기를 보였다. 이화명나방유충은 높은 농도에서는 차이가 없었으나 50~200마리/ml의 낮은 농도에서는 함양산 Heterorhabditis sp.(47.3~100%)가 한림산 Stelnemema sp.(34.3~83.3%) 보다 효과적이었다. 밤바구미와 복숭아명나방유충에 대하여 유충 한 마리당 10, 20 마리의 산칭산 Stemernema sp. 와 함양산 Heterorhabditis sp. 를 처리하여서는 각각 50.0%와 80.0%와 90.0%, 70.0%와 90.0%, 90.0%와 100%의 치사율을 얻었다. 유충 한 마리당 10, 20 마리의 선충을 처리하였을때 노랑털알락나방유충은 포천산 Steinernema sp.에 대하여 매우 감수적이었으나(96.7%~100%) 동래산 Steinernema sp.에서는 낮은 치사율을 보였다.(63.3%~76.7%)