白僵菌和绿僵菌在农业害虫防治中的应用研究进展

本文就白僵菌和绿僵菌的主要防治对象及其中毒症状,中毒机制,主要剂型和防治效果做了介绍。     

黑光灯和白僵菌无纺布对青杨脊虎天牛的防治效果

为探索青杨脊虎天牛的无公害控制技术,采用不同波长(320~560 nm)黑光灯对其成虫进行诱捕。结果,青杨脊虎天牛成虫对低波长区间(320~368 nm)具有趋光性,对368 nm(黄)较360 nm(绿)更为敏感,处理时间18:00—24:00中,最佳诱捕时间为20:00—22:00,晴天的诱捕效果要比晴转阴和阴天要好,黑光灯可作为监测和控制青杨脊虎天牛的监测辅助工具。测定7种白僵菌菌株制作的无纺布菌条对青杨脊虎天牛的毒力,各菌株在处理后30 d内孢子含量逐渐下降,对青杨脊虎天牛防治效果最佳的菌株为球孢白僵菌Bb01和布氏白僵菌Bb CF327。     

Biological response of chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), to various regimes of chemical and biorational insecticides

The chilli thrips Scirtothrips dorsalis (Hood) (Thysanoptera: Thripidae), a new invasive pest in the USA, is an economically important pest of certain vegetable, ornamental and fruit crops in southern and eastern Asia, Oceania and parts of Africa. These crops cannot be protected from the pest without resorting to the use of chemical insecticides. In order to forestall or delay the development of insecticide resistance in S. dorsalis, we continued our focus on the discovery of insecticides with different modes of action for rotational use. In this study we evaluated candidate insecticides to control S. dorsalis on ‘Jalapeno’ pepper, Capsicum annuum L.; these materials belong to different IRAC mode of action classes as follows: (i) 4A – neonicotinoids, i.e., imidacloprid, thiamethoxam and dinotefuran, (ii) 5 – spinosyns, i.e., spinosad and spinetoram, (iii) 3A – pyrethroids, i.e., β-cyfluthrin, esfenvalerate, ζ-cypermethrin and λ-cyhalothrin and (iv) 8D – borax mixed together with orange oil and detergents in the TriCon^® formulation. In addition we evaluated the entomopathogenic fungus, Beauveria bassiana (Botanigard^®) alone and in combination with the borax formulation at ½ of their usual rates of application. Each of the 3 neonicotinoid insecticides when applied either as a single foliar spray or as a soil drench significantly suppressed both adults and larvae for at least 10 days; indeed imidacloprid did so for 15 days. Dinotefuran was more effective as a foliar spray than as a soil drench. Spinosyns applied as a single foliar spray, significantly suppressed both adults and larvae through 15 days after treatment (DAT). None of the 4 pyrethroids provided significant suppression of either adults or larvae. The borax formulation suppressed adults and larvae through 10 DAT. B. bassiana significantly suppressed only the larvae at 5 DAT and not at 10 DAT. This study brings the number of insecticides known to be effective against S. dorsalis to 10 and these belong to 7 different modes of action classes. The use of such insecticides in rotation belonging to different classes will help delay the development of insecticide resistance in S. dorsalis.     

PGPR and entomopathogenic fungus bioformulation for the synchronous management of leaffolder pest and sheath blight disease of rice

BACKGROUND: The biological control of plant pests and diseases using a single organism has been reported to give inconsistent and poor performance. To improve the efficacy, bioformulations were developed possessing mixtures of bioagents. RESULTS: Bioformulations combining Pseudomonas fluorescens Migula strains Pf1 and AH1 and Beauveria bassiana (Balsamo) Vuill. isolate B2 were developed and tested for their efficacy against leaffolder pest and sheath blight disease on rice under glasshouse and field conditions. The combination of Pf1, AH1 and B2 effectively reduced the incidence of leaffolder insect and sheath blight disease on rice compared with other treatments. An in vitro assay of leaffolder preference to rice leaf tissues treated with Pf1 + AH1 + B2 biformulation showed variation from normal growth and development of leaffolder larvae. Plants treated with the Pf1 + AH1 + B2 combination showed a greater accumulation of enzymes, lipoxygenase and chitinase activity against leaffolder insect compared with other treatments. Similarly, the plants showed a higher accumulation of defence enzymes, peroxidase and polyphenol oxidase activity against sheath blight pathogen in Pf1 + AH1 + B2 treatment compared with the untreated control. The bioformulation mixture attracted the natural enemy population of leaffolder under field conditions. In addition, a significant increase in rice grain yield was observed in Pf1 + AH1 + B2 treatment compared with the untreated control. CONCLUSION: The combination of P. fluorescens strains and B. bassiana isolate effectively reduced the incidence of leaffolder insect and sheath blight disease on rice plants and showed the possibility of controlling both pest and disease using a single bioformulation. Copyright © 2010 Society of Chemical Industry     

维生素对白僵菌生长和液生分生孢子形成的影响

对球孢白僵菌在不同维生素为生长辅助因子的液体培养基中菌丝生长和液生分生孢子的形成进行研究。结果表明,不同维生素对球孢白僵菌的生长及液生分生孢子的形成影响极显著。在培养液中添加适宜的维生素能有效地刺激液生分生孢子的形成,VB6+VB1+VB2或复合维生素B能使球孢白僵菌获得较高的液生分生孢子产量,产孢量分别高达5.03×1011个·L-1和5.12×1011个·L-1。同时试验还表明,液生分生孢子的产量与维生素组合有关,复杂的维生素组合比单一的维生素更有利于液生分生孢子的形成。     

白僵菌对烟草粉螟的致病性研究

为了研究白僵菌对烟草粉螟的致病性,开展了5株白僵菌(FJNLD-1、FJNLD-2、FJNLD-3、FJNLD-4、FJNLD-5)对烟草粉螟的致病性试验。结果表明:5株白僵菌分生孢子、菌丝对烟草粉螟的致病性有一定差异,其中FJNLD-2的感染致死效果最好,其孢子悬液的致死率达82.11%,菌丝悬液的致死率达77.32%,菌株发酵产物对粉螟的致死率最高,可达85.00%。     

白僵菌防治森林害虫的研究与应用

综述了白僵菌在森林害虫生物防治中的研究与应用概况,主要包括:白僵菌防治森林害虫的主要种类,白僵菌对昆虫的致病机理,白僵菌致病力的影响因素,以及白僵菌在生物防治中的应用前景。     

白僵菌及其伴生菌发酵液对线虫的毒力研究

采用发酵液浸没法,以4种线虫作为靶标,对6株白僵菌、7株伴生菌菌株进行了杀线虫活性筛选,以期获得新的、高效的杀线虫生防菌资源。其中:处理24 h对南方根结线虫Meloidogyne incognita 2龄幼虫及大豆胞囊线虫Heterodera glycines 2龄幼虫校正死亡率均达80%以上的菌株仅有白僵菌Snef2598及伴生菌Snef5;供试菌株对水稻干尖线虫Aphelenchoides besseyi的毒力均较低,其中仅有1株白僵菌校正死亡率达到40%以上。处理48 h对南方根结线虫2龄幼虫校正死亡率达90%以上的菌株有白僵菌4株和伴生菌5株;对大豆胞囊线虫2龄幼虫校正死亡率超过90%的菌株有白僵菌3株和伴生菌1株;供试菌株对水稻干尖线虫毒力均较低,校正死亡率达60%以上的菌株有白僵菌3株和伴生菌2株;几乎所有供试菌株,对小杆线虫Caenorhabditis sp.的毒力均很高,处理24 h及48 h的校正死亡率均达97%以上,且被杀死的小杆线虫体壁以及虫体内部物质均被不同程度地消解。研究表明,球孢白僵菌菌株Snef2598及其伴生菌菌株Snef5对4种靶标线虫的毒力均较好,具有进一步研究的价值。     

白僵菌生产工艺规范化的研究

通过时白僵菌生产工艺规范化的研庞,确立了规范化生产工艺流程及生产工艺各环节的优化参数,筛选出液体和固体培养基的优配方;确定团体培养空的最适培养温度头３ｄ为１６℃～２２℃;适宜相对湿大在培养的第１ｄ为９５％以上,第２～３ｄ为９５％～１００％;菌粉干燥的温度应控制在３５℃～３８℃,时间为４０ｈ～２４ｈ;研制和确立了规范化生产工艺的配套机械。通过研究,生产用期比现有工艺缩短５１．１％,生产成本比现有工艺下降２１．３５％。