褐飞虱寄生性天敌两索线虫生活史的研究

两索线虫(Amphimermis sp.)的幼虫寄生于褐飞虱、灰飞虱等害虫的体内,使宿主产生一系列的病理变化,直至死亡。本文较详细地报导了湖北省褐飞虱寄生性天敌两索线虫的生活史。在实验室内用感染期幼虫作感染褐飞虱的试验获得成功。根据该虫的生活史和生态习性,在汉阳县的两索线虫孳生田里,采用与水稻高产栽培相结合的保护线虫措施,可以在褐飞虱中等发生量的年份,有效地控制褐飞虱的危害。

LIFE CYCLE OF AMPHIMERMIS SP. A NEMATODE PARASITE OF THE BROWN PLANTHOPPER IN CHINA

The brown planthopper,Nilaparvata lugens is one of the injurous pests of rice in south China.In recent years biological investigations were carried out which revealed that this insect pest has often infected by a nematode belonging to the genus Amphimermis in considerable intensity.The ecological condition and life cycld of this nematode had been preliminarily studied. It showed some important way for controlling this insect pest.Amphimermis had usually one generation every year. Males measured 2.1-3.0 cm in length, females 3.7-5.1cm. Sex conjugation performed usually in May to August, and eggs laid in water of rice field. The eggs could be found in rice field from June to September,mostly in August.Eggs measured 0.050-0.066×0.050-0.067mm. The juvenile after hatching become infective stage,wandered on the surface of water or climbed on the lower stem of the rice plant. If it happened to meet the proper insect host, the infective juvenile penetrated into the host with its mouth stylet and began its parasitic life. After 2 to 3 weeks, the parasitic juvenile left the host insect by passing through the insect segmental membrane.Then the host insect died at once. After left the host, the juvenile became post-parasitic(preadult stage) and passed a free-living stage in soil for a long time. Usually in next spring, the post-parasitic juvenile had its final molting and became adult.In years of moderate infestation of the brown planthopper, damage to rice crops could be prevented by conservation of Amphimermis with proper cultural measures.