摘要
昆虫病原线虫是隐蔽性害虫的有效生物防治因子,对8种斯氏线虫和3种异小杆线虫进行筛选证实夜蛾斯氏线虫Steinernema feltiae对甘薯蚁象Cylas formicarius的致病力最强;在此基础上进一步研究了11个不同地理来源的S.feltiae品系对甘薯蚁象末龄幼虫的致病力,获得强致病力的品系S.feltiae JY-17并测定了不同因素对该线虫品系致病力的影响。研究结果表明:在25℃条件下,甘薯蚁象不同发育阶段对S.feltiae JY-17的敏感性依次为末龄幼虫>低龄幼虫>蛹>预蛹期>成虫;在不同测试温度条件下,S.feltiae JY-17致病力由高到低顺序为25℃>20℃>30℃>15℃>10℃>35℃;在25℃条件下,当寄主密度为196.6头.m 2时,线虫对蚁象末龄幼虫的LD50=5.532条.头1,LD90=28.049条.头1;当线虫与寄主比例为5:1时,LT50=44.306 h。本研究为利用昆虫病原线虫防治甘薯蚁象提供了理论依据。
Entomopathogenic nematodes （EPN） are effective biological control factors against cryptic pests. Virulence of 8 Steinernema spp. and 3 Heterorhabditids spp. against last instar larvae of sweetpotato weevils Cylas formicarius were evaluated and Steinernemafeltiae showed the highest virulence. Then the virulence of 11 S. feltiae strains originated from different geographical locations were tested, S. feltiae JY-17 was the best one against the last instar larvae of C. formicarius. Effect of different factors on the virulence of S. feltiae JY-17 to C. formicarius was determined. The results showed that the sensitivity of insect stages at 25 ℃ were in a sequence of last instar larvae 〉young larvae 〉pupa〉pre-pupa〉 adult; the virulence of S. feltiae JY-17 to C. formicarius were in an order of 25 ℃ 〉20 ℃ 〉 30 ℃ 〉 15 ℃ 〉 10 ℃ 〉 35 ℃. The LDs0 and LD90 of nematodes to the last instar larvae of C. formicarius were 5.532 IJs.larva-1 and 28.049 IJs.larva＆-1 at 25 ℃ and in the density of 196.6 larva.m^-2 respectively. LTs0 of nematodes to the last instar larvae of C. formicarius was 44.306 h when the ratio of nematode to insect was 5 ： 1. The present study provides some useful information on the biocontrol of sweetootato weevils with EPN.
出处
《中国生物防治学报》
CSCD
北大核心
2012年第4期514-520,共7页
Chinese Journal of Biological Control
基金
国家甘薯产业技术体系(CARS-11-8-B)
关键词
昆虫病原线虫
甘薯蚁象
致死率
侵入率
entomopathogenic nematodes
Cylasformicarius
mortality
invasion rate
