Abstract
Pathogenicity of entomopathogenic nematde, Steinernema carpocapsae Pocheon strain (ScP) was evaluated against different larval stages(2nd, 3-4th and 5th) of Anomis commode and Anomis mesogona(Lepidoptera: Noctuidae) in petri dish and pot. The $LC_{50}$ values were increased in proportion to larval stage of A. commoda and A. mesogona. $LC_{50}$ value of ScP against 2nd instar of A. commoda and A. mesogona was 9.7 and 4.5, respectively. The 2nd instar of both species was also susceptible to ScP in pot test. That is, mortality of 2nd instar of A. commode and A. mesogona was higher representing $72.5\%\;and\;87.5\%$ 5 days later after treatment, respectively, when ScP was applied at the ,ate of 90,000 infective juveniles(Ijs) per $pot(=1\times10^9\;Ijs/ha)$. However, susceptibility was decreased from 3rd instar. Mortality of 5th instar of A. commoda and A. mesogona was $5.0\%\;and\;10.0\%$, respectively, at the rate of 90,000 Ijs/pot. When ScP was applied into pot including mixed larval stages from 2nd to 5th instar(10 larvae far 2nd instar, 10 larvae for 3rd - 4th instars, and 10 larvae for 5th instar) at the rate of 90,000 Ijs/pot, mortality of A. commoda and A. mesogona was $69.2\%\;and\;50.0\%$, respectively.
무궁화의 중요한 식엽성 해충인 무궁화잎밤나방(Anomis mesogona)과 큰붉은잎밤나방(Anomis commoda)에 대한 곤충병원성 선충 Steinernena carpocapsue 포천 계통(ScP)의 병원성을 실내 petri dish와 pot에서 령기별(2령, 3-4령, 5령)로 검정하였다. 큰붉은잎밤나방과 무궁화잎밤나방에 대한 반수치사농도$(LC_{50})$는 령기가 높아질수록 증가하여 선충에 대한 감수성이 감소하였는데, 2령충의 경우 각각 9.7과 4.5였다. 그리고 Pot에서도 ScP의 병원성은 령기에 따라 차이를 보였다. ScP는 큰붉은잎밤나방과 무궁화잎밤나방의 2령충에 대하여 가장 높은 치사율을 보였는데, 90,000마리/pot($=1\times10^9$ 마리/ha) 처리 시 각각 $72.5\%$와 $87.5\%$의 치사율을 보였다. 반면 3-4령충부터는 병원성이 감소하여 큰붉은잎밤나방과 무궁화잎밤나방 5령충에 대해서는 처리 5일 후, 90,000마리/pot 처리 시 각각 $5.0\%$와 $10.0\%$의 치사율만 나타내었다. Pot에 2령충과 3-4령충, 5령충을 각각 10마리씩 접종한 후, ScP를 90,000마리/pot 농도로 처리하였을 때, 큰붉은잎밤나방과 무궁화잎밤나방의 치사율은 각각 $69.2\%$와 $50.0\%$였다.
