Mahar Ali Nawaz, Munir Muhammad, Elawad Sami, Gowen Simon Richard, Hague Nigel Graham Meckenzi
Department of Agriculture, University of Reading, Reading RG6 6AT, UK.
J Zhejiang Univ Sci B. 2005 Jun;6(6):457-63. doi: 10.1631/jzus.2005.B0457.
The entomopathogenic bacterium, Xenorhabdus nematophila was isolated from the hemolymph of Galleria mellonella infected with Steinernema carpocapsae. The bacterial cells and its metabolic secretions have been found lethal to the Galleria larvae. Toxic secretion in broth caused 95% mortality within 4 d of application whereas the bacterial cells caused 93% mortality after 6 d. When filter and sand substrates were compared, the later one was observed as appropriate. Similarly, bacterial cells and secretion in broth were more effective at 14% moisture and 25 degrees C temperature treatments. Maximum insect mortality (100%) was observed when bacterial concentration of 4x10(6) cells/ml was used. Similarly, maximum bacterial cells in broth (95%) were penetrated into the insect body within 2 h of their application. However, when stored bacterial toxic secretion was applied to the insects its efficacy declined. On the other hand, when the same toxic secretion was dried and then dissolved either in broth or water was proved to be effective. The present study showed that the bacterium, X. nematophila or its toxic secretion can be used as an important component of integrated pest management against Galleria.
昆虫病原细菌嗜线虫致病杆菌（Xenorhabdus nematophila）是从感染了小卷蛾斯氏线虫（Steinernema carpocapsae）的大蜡螟（Galleria mellonella）血淋巴中分离得到的。已发现该细菌细胞及其代谢分泌物对大蜡螟幼虫具有致死性。肉汤中的毒性分泌物在施用后4天内导致95%的死亡率，而细菌细胞在6天后导致93%的死亡率。当比较滤纸和沙子基质时，发现后者更合适。同样，在14%湿度和25摄氏度温度处理下，肉汤中的细菌细胞和分泌物效果更佳。当使用4×10⁶个细胞/毫升的细菌浓度时，观察到最大昆虫死亡率（100%）。同样，肉汤中的细菌细胞在施用后2小时内，95%的细胞穿透进入昆虫体内。然而，当将储存的细菌毒性分泌物施用于昆虫时，其效力会下降。另一方面，当将相同的毒性分泌物干燥后，再溶解于肉汤或水中，证明是有效的。本研究表明，嗜线虫致病杆菌或其毒性分泌物可作为综合害虫管理中防治大蜡螟的重要组成部分。
