摘要
梨网蝽Stephanitis nashi是多种果树和园林植物上的重要害虫,在长江流域、华北地区为害严重。梨网蝽发生世代多,易产生抗药性,筛选出能替代化学农药的生物控制因子,是对梨网蝽实现有效可持续控制的重要手段。本文通过菌株筛选平台,挑选出产孢较好的15株昆虫病原真菌,用喷雾法测定其对梨网蝽成虫和若虫致病力的差异。在1.0×106孢子/m L孢子悬浮液接种后,菌株Bb2359等6株球孢白僵菌和1株金龟子绿僵菌Ma67对梨网蝽成、若虫累积死亡率均达到100%,其中菌株Bb2352、Bb2359、Bb2372等对成虫的LT50小于4 d,而菌株Bb2352、Bb2359、Ma67对2龄若虫的LT50均在5 d以内,LT50显示菌株对成虫的致死速度要快于对若虫的致死速度。在时间-剂量-死亡模型研究中,梨网蝽成、若虫在接种后的第3 d到第7 d,累积死亡率均呈直线快速上升趋势,而在前后均变化平缓。同时,各菌株均表现出明显的死亡率随接种浓度增高而不断增高的剂量效应。菌株Bb2359对梨网蝽成虫、若虫均显示出很高的毒力水平,致死中浓度LC50分别为6.466×104和4.747×104孢子/m L;在1.0×107孢子/m L浓度下致死中时LT50分别为2.89和3.54 d。该菌株具备高效快速的杀虫特点,具有开发为真菌生物农药的巨大潜力。
Stephanitis nashi is one of the most destructive sap-sucking insect pests on various fruit and garden plants, especially in the regions of the Yangtze valley and Northern China. The pest reproduces many generations per year and easily develops resistance to chemical pesticides. Biological control might be helpful in reducing the selection pressure for resistance to chemical insecticides and in the sustainable control of the pest. The potential of entomopathogenic fungi as a biological control agent against the pest was evaluated in the laboratory assays. Fifteen strains of entomopathogenic fungi with good sporulation were tested for their pathogenicity both on S. nashi adults and the 2nd instar nymphs. The cumulative mortalities of six Beauveria strains and one Materhazium strain reached 100% both on S. nashi adults and the 2nd instar nymphs at an inoculation concentration of 1×10^6conidia/m L. The LT50 of the strains of Bb2352, Bb2359 and Bb2372 against the adults were less than four days, while the LT50 of the strains of Bb2352, Bb2359 and Ma67 against the 2nd instar nymphs were less than five days. The LT50 difference between the adults and the nymphs showed the adults could be knocked down more quickly. In the time-dose-mortality model, the cumulative mortality of the pest increased sharply from the 3rd to the 7th day after the fungal innoculation, while showed only gentle changes before and after that period. The mortalities increased with the increase of inoculation dosage, presenting an obvious dose response. The strain Bb2359 showed the highest virulence against both S. nash adults and its nymphs, with a LC50 of 6.466×10^4 conidia/m L and of 4.747×10^4 conidia/m L, respectively. The LT50 for the adults and nymphs were 2.89 d and 3.54 d, respectively, at an inoculation concentration of 1×10^7 conidia/m L. This strain showed a great potential in the control of the hazardous S. nash as a fungal insecticide.
出处
《中国生物防治学报》
CSCD
北大核心
2015年第6期853-859,共7页
Chinese Journal of Biological Control
基金
国家自然科学基金(31471822)
安徽省年度重点项目(1301043049)
安徽省科技计划重点项目(2013NK2009)
关键词
梨网蝽
成虫
若虫
昆虫病原真菌
生物测定
Stephanitis nashi
adult
nymph
entomopathogenic fungi
bioassay
