斯氏线虫对黄曲条跳甲种群系统控制研究

将斯氏线虫作为一个生物控制因子引入黄曲条跳甲种群系统中,把斯氏线虫对该跳甲各虫期的感染率作为量化指标,应用种群发展趋势指数(I)和干扰作用控制指数(IIPC)分析方法,评价斯氏线虫对黄曲条跳甲自然种群的控制作用。结果表明,十字花科蔬菜田中每hm~2施用7×10~9条斯氏线虫对黄曲条跳甲种群有明显控制作用,对照区的种群趋势指数为12.9,处理区的种群趋势指数下降为2.39。斯氏线虫对黄曲条跳甲种群干扰作用控制指数为0.2,即线虫处理区的下代跳甲种群密度将是对照区的0.2倍。

STUDIES ON THE POPULATION SYSTEM CONTROL OF STEINERNEMA CARPOCAPSAE(WEISER) AGAINST STRIPED FLEA BEETLE PHYLLOTRATATA STRIOLATA (FABRICIUS) (COLEOPTERA: CHRYSOMELIDEA)

As a biocontrol agent, the Steinemema carpocapsae (Weiser) was brought into the population system of striped flea beetle (SFB) Phyllotrata striolata (Fabricius), the infection rate of the nematode in differdnt stages (and larval instars) of the beede were adopted as quantitative standard, and the index of population trend (I) and interference index of population control (IIPC) analyses were used to evaluate the control effect of S. carpocapsae against SFB. The results showed that after 7×10⁹ nematodes/hm². was applied in the soil of crucifer vegetable field, the I value of SFB only 2.39, significantly lower than 12.9, that of the check plot without nematode treatment, and the IIPC value in treated plot was only 0.2, i.e. the population density of SFB in next generation in treated plot would be 0.2 times as many as the check plot.