应用斯氏线虫防治多纹豹蠢蛾的研究

A STUDY ON THE APPLICATION OF STEINERNEMA SPP. FOR CONTROL OF ZEUZRA MULTISTRIGATA MOORE

本文通过对斯氏属9个线虫品系在不同温度下对多纹豹蠹蛾侵染力的测定,筛选出Steinernema feltiae Beijing为最佳品系;它能寄生低、中、高龄幼虫及蛹;温度在25℃时线虫的侵染力最强,可在2-4d内把害虫致死;线虫在虫道内能主动扩散到8cm处毒杀寄主。供试的其它8个线虫品系也能不同程度地致死害虫,并在死虫体内增殖。线虫的使用剂量对多纹豹蠹蛾的致死速度及效果有影响,以每害虫1000条侵染期线虫为最适剂量。4种施用方法比较表明,用带线虫的塑料海绵塞虫孔效果好,操作、携带最方便;室内对多纹豹蠹蛾幼虫的致死率达100％,林间大区防治效果达88.6-97.0％。

Casuarina tree, a main tree species in Fujian Province in sandwind break, is infested by Zeuzera multistrigata Moore. The results showed that Steinernema feltiae, an entomopathogenic nematode, was an effective parasite to suppress the population of Zeuzera pest. The comparison of infectivity of 9 steinernematid strains indicated that Steinernema feltiae Beijing is the best one. The Zeuzera larvae, young and mature, and pupae were all infected by Beijing strain of Ste- inernema feltiae. The temperature had effect on the mortality and killing speed of Zeuzera larvae infected by nematodes. The temperature range for nematodes infection is from 15-30℃. The quickest killing speed was gained at 25℃ with the mortality of 100% within 48 hours. The nematode was able to spread to the distance of 8cm to parasitize Zeuzera larvae in an infested tunnel. Application dosage of the nematode influenced the mortality of Zeuzera larvae. 61.5% and 100% larvae died under the dosage of 50 500 nematode juveniles per ml respectively. No difference in mortality happened when the dosage of nema- tode was above 500 juveniles per ml.Four methods of nematode application were tested. The best method is to stuff a small spiece of foam mixed with ne- matodes about 1000 juveniles. This application method was used in 25.3 he- ctares for control of Zeuzera larvae in Fujian Province.