2种昆虫病原线虫对松褐天牛幼虫的控制力测定

Laboratory Test on Control of Japanese Pine Sawyer by Two Entomopathogenic Nematode Species

为探讨利用昆虫病原线虫小卷蛾斯氏线虫ALL品系和异小杆线虫的WG品系防治松褐天牛的可行性,在室内模拟松褐天牛的自然状态的条件,利用以上2种线虫对松褐天牛3龄幼虫进行防治试验并用时间-剂量-死亡率(TDM)模型拟合控制效果方程。结果表明:在3,4,5,6万条.mL-1的剂量下经过7天,小卷蛾斯氏线虫的ALL品系可致死松褐天牛3龄幼虫的百分比分别为41.11%,51.11%,53.33%,82.22%,而异小杆线虫的WG品系可致死松褐天牛3龄幼虫百分比分别为35.56%,51.11%,51.11%,74.44%。异小杆线虫的WG品系的起效速度要比小卷蛾斯氏线虫的ALL品系快,二者的致死峰值主要集中在第1—3天。由TDM模型求得小卷蛾斯氏线虫的ALL品系在第1—7天的LC50分别为52888176,147128.61,25953.95,17915.36,14964.30,12968.78,11663.99mL-1;异小杆线虫的WG品系在第1—7天的LC50分别为326212.05,29566.51,14474.38,13934.78,12234.89,10531.74,9543.33mL-1。小卷蛾斯氏线虫的ALL品系以4,5,6万条.mL-1的剂量处理时的LT50分别是6.70,4.97,3.98天;异小杆线虫的WG品系以5,6万条.mL-1的剂量处理时的LT50分别为5.39,4.06天。试验结果表明小卷蛾斯氏线虫ALL品系和异小杆线虫WG品系的线虫对松褐天牛的低龄幼虫有较高的毒性,为进一步进行野外防治提供了依据。

To explore the feasibility of controlling Monochamus alternatus by using entomopathogenic nematodes Steinernema carpocapsae ALL and Heterorhabditis sp.WG,the natural state conditions of M.alternatus were simulated in laboratory,and control effect with the two entomopathogenic nematodes on the larvae of Japanese pine sawyer were determined.The TDM（time-dose-mortality） model of control function of the two nematodes against M.alternatus was established and tested.The results showed that under the doses of 30 000,40 000,50 000 and 60 000 mL^-1 for seven days,41.11%,51.11%,53.33% and 82.22% individuals of M.alternatus at the 3rd instars were killed by S.carpocapsae ALL respectively;and 35.56%,51.11%,51.11% and 74.44% individuals were killed by H.sp.WG,respectively.The start time of killing M.alternatus at the 3rd instars by H.sp.WG was earlier than that by S.carpocapsae ALL.The peak of daily mean mortality of M.alternatus at the 3rd instars was between the 1st day to 3rd day.The LC50 values of S.carpocapsae ALL between the 1st day and 7th day were calculated by the TDM model and they were 52 888 176,147 128.61,25 953.95,17 915.36,14 964.30,12 968.78 and 11 663.99 mL^-1,respectively;and the LC50 values of H.sp.WG of the 1st day to 7th day were 326 212.05,29 566.51,14 474.38,13 934.78,12 234.89,10 531.74 and 9 543.33 mL^-1,respectively,and under the doses of 40 000,50 000 and 60 000 mL^-1,the LT50 of S.carpocapsae ALL was 6.70,4.97,and 3.98 days,respectively;and under the doses of 50 000 and 60 000 mL^-1,the LT50 of WG was 5.39 and 4.06 days,respectively.It is concluded that the two of nematodes species have a high control effect on the larvae of M.alternatus,which provides a basis for field control of M.alternatus.