喷雾法施用线虫大面积防治荔枝拟木蠹蛾

荔枝拟木蠹蛾(Arbela dea Swinhoe)是南方荔枝、木麻黄等主要的钻蛀害虫,作者利用拟木蠹蛾昼伏夜出的习性,用大蜡螟幼虫诱测和回收喷雾荔枝拟木蠹蛾粪道上的线虫(Steinernema carpocapsae Agriotos),不同温度、不同粪道大小对线虫存活影响的测试结果表明,应用1×10~3/ml线虫剂量喷雾拟木蠢蛾挂在树上的粪道,粪道上便有足够数量的线虫和时间使寄主感染。1995年喷雾法施用线虫防治荔枝拟木蠹蛾260hm~2,防治效果在85％～100％,平均为94.28％,有效地压低了田间的虫口密度。解决了树冠嫩枝受害后人工难以注射及倒置斜垂坑道的虫口防治效果差的矛盾,也使利用病原线虫防治害虫这一有效的生物防治手段更容易为果农所接受。

MASS APPLICATION OF ENTOMOGENOUS NEMATODE AGAINST LICHI STEM BORER

In consideration of the nocturnal outgoing behavior of lichi stem borer(LSB) Arbela dea Swinhoe, a dominant boring insect pest on lichi and other fruit and forest trees in South China, an attempt was made to use exterior spraying of entomogenous nematode Steinernema carpocapsae Agriotis against this insect pest. It was confirmed by the detection with larger wax moth larvae that after spraying the excrement strip of LSB outside the cannel had been contaminated by nematode. The effects of temperature and size of excrement strip on the survival of nematode were tested, the results showed that a preparation contained 1×10³ nematodes/ml was sufficient to make LSB infected. Based on these results, a mass application of this nematode in 260 hm² of lichi plantations was conducted, and 85%-94.28%-100% of mortalities of this borer were obtained, and its density was effectively reduced. The difficulties that to inject the nematode preparation into tender twigs of canopy and the lower control effect of injection into slope or invert cannels were extricated, and this new and more easy bio-control method for using entomogenous nematode against insect borer would be well accepted by orchard farmers.