新型储粮保护剂硅藻土对2种重要储粮害虫的防治效果初报

为了探索硅藻土防治储粮害虫的经济有效剂量、防治方法和条件等,本方设计了不同温度和湿度组合,不同的硅藻土剂量分别对生活在小麦和稻谷中的谷蠹和长角扁谷盗的毒力试验,结果表明:在相同的条件下(1)硅藻土对小麦的防护优于对稻谷的防护。(2)在25℃时对谷蠹的防效高于30℃的防效,对长角扁谷盗则相反。(3)硅藻土的防治效果随着相对湿度的降低而提高。(4)长角扁谷盗对硅藻土的敏感度是谷蠹的5￣6倍。在应用时从经济、有效的原则考虑,建议防治以谷蠹为主要害虫的储粮时以400mg/kg的剂量,防治长角扁谷盗时则以70mg/kg即可。     

高大平房仓整仓富氮低氧气调防治储粮害虫研究

富氮低氧气调储粮是一项无公害、无污染、“零排放”的绿色储粮新技术,是近年来绿色生态储粮技术的主要手段和发展方向.良好的仓房气密性是气调储粮技术得以成功运用的关键,本次研究实验仓房粮面没有采用薄膜压盖密闭处理,直接进行整仓气调作业,并使氮气浓度达到98％以上,维持一定时间,通过对所得实验数据的分析,结果表明整仓富氮低氧气调具有较好的实用性,对锈赤扁谷盗和谷蠹均有明显杀灭效果,而且整仓气调可以解决膜下富氮低氧气调工艺存在的空间防治问题,并减少劳动强度.     

谷蠹的趋光行为及部分影响因素研究

为探讨昆虫的趋光性和灯光诱捕技术在储粮害虫防治中的应用,在实验室条件下探究了光源波长、光强、虫龄、虫口密度和饥饿处理对谷蠹成虫趋光行为的影响。结果表明,在可见光区,谷蠹趋光性较强的波长范围在530nm和575nm,在紫外光区,谷蠹趋光性较强的波长为365、385和395nm。在一定的光强范围内,谷蠹的趋光性随光强度的增强而增大。随着日龄的增加,趋光性先增强后逐渐减弱,10~15日龄成虫的趋光性最强。随着成虫饥饿处理时间的延长,谷蠹的趋光性先增强后减弱,饥饿处理2d的趋光性最强。随着释放虫口密度的增加,谷蠹的趋光性增强。研究结果为谷蠹灯光诱捕技术的研究和应用提供了一些参考。     

臭椿树皮提取物对谷蠹成虫的控制作用研究

采用索氏提取法,以乙醚作为有机溶剂制备臭椿树皮提取物,并研究其对谷蠹成虫的控制作用。结果表明：臭椿树皮提取物对谷蠹成虫具有较强的驱避作用和熏蒸作用,触杀作用较弱。处理12h后,各个处理浓度的驱避率均达到Ⅴ级。在臭椿树皮提取物与丙酮1∶5（体积比）浓度下熏蒸处理4 d后,校正死亡率达到73.73%。     

应用紫外高压诱杀灯防治储粮害虫

紫外高压诱杀灯一天能诱杀98333头谷蠹、42头锈赤扁谷盗、684头麦蛾、120头米扁虫和411头书虱。与选筛法比较,它能提前20～90天检查出谷蠹,提前18～34天检查出锈赤扁谷盗,提前66～73天检查出麦蛾。由于它能诱杀越冬代成虫,使它们不能返回粮面产卵,压低了下代的发生量,同时,适时施用仓虫敌控制麦蛾和书虱,有2个试验仓的虫口密度一直被控制在较低水平,实现了全年不熏蒸,其防治费用为1015元,而对照仓为1855元。它是一种理想的新型测报防虫器械。     

Effect of uneven application of azadirachtin on reproductive and anti-feedant behaviour of Rhyzopertha dominica (Coleoptera: Bostrichidae)

The effects of uneven application of an azadirachtin-enriched neem extract to wheat grain on the reproduction and feeding behaviour in Rhyzopertha dominica (F) were investigated. The evenness of distribution amongst individual wheat grains during grain treatment was not important in ensuring its effectiveness as an anti-feedant or as an insect growth regulator, provided that, overall, the grain was treated with an effective level of azadirachtin. The effect of azadirachtin on reproduction was not improved when the diluent application rates were increased from 0.5 ml kg⁻¹ to 5 ml kg⁻¹. Treating 10% of the grain was shown to provide the same level of protection as treating 100% of the grain. The anti-feedant effect of azadirachtin on the beetle was also unaffected by unevenness of treatment, provided that 50% of the grain was treated. The fact that azadirachtin remains effective even when application to grain is uneven may be advantageous in field situations where uniform distribution of insecticides is difficult to achieve. © 1999 Society of Chemical Industry     

不同温度下玉米象与谷蠹种内和种间竞争研究

参照Giga的方法在28℃和33℃下研究玉米象与谷蠹的种内和种间竞争,结果表明单独饲养下玉米象与谷蠹的生殖曲线均为抛物线型,属于资源利用竞争型,种内竞争强度取决于初始虫口密度。玉米象与谷蠹混合饲养的种群数量均明显小于单独饲养的种群数量,两物种为争夺有限的资源产生竞争,种间竞争强度取决于初始虫口密度和温度条件。在28℃下玉米象生殖曲线为凸型,是强竞争者,将长期占据统治地位;在33℃下谷蠹的竞争能力增强,生殖曲线由28℃下的凹型转变为33℃下的凸型,将有可能占据决定地位,但玉米象在较高虫口密度下生殖曲线仍为凸型,竞争结果最终可能会导致两物种共存。     

温度对谷蠹未成熟期生长发育的影响

在22,25,28,31,34,37℃等6种不同恒温奈件下研究谷蠹的生长发育特性,结果表明温度对谷蠹未成熟期各虫态的发育历期影响显著,卵、幼虫和蛹的发育速率与温度之间的关系在总体上呈逻辑斯蒂曲线;幼虫龄期在3—6龄间变化;整个未成熟期的发育起点和有效积温分别是14．0591℃和704．5290日度;未成熟期的存活率在28℃最高,高温和低温降低谷蠹的存活率．     

Efficacy of Bacillus thuringiensis Cry3Aa protoxin and protease inhibitors against coleopteran storage pests

BACKGROUND: Environmental impacts and resistance to insecticides pose serious challenges to stored‐product insect and other types of pest control. Insect‐resistant transgenic grain is a potential alternative to fumigants, but candidate control proteins are needed, especially for coleopterans. Therefore, we evaluated the efficacy of a coleopteran‐active toxin, Bacillus thuringiensis Cry3Aa, with or without protease inhibitors, in laboratory feeding assays against coleopteran storage pests. RESULTS: In a comparison of the toxicity of Cry3Aa protoxin towards three species of coleopteran storage pests, Tenebrio molitor L. was found to be most sensitive, Tribolium castaneum (Herbst.) was most refractory and Rhyzopertha dominica F. displayed an intermediate response. For R. dominica, Cry3Aa combined with 3500 mg potato carboxypeptidase inhibitor or 5000 mg aprotinin kg^?1 diet resulted in both delayed development and increased mortality. Potato carboxypeptidase inhibitor and bovine aprotinin reduced the LC₅₀ of Cry3Aa for R. dominica two‐ and threefold respectively. Cry3Aa treatment resulted in fewer progeny from R. dominica, and progeny was further reduced when the protoxin was combined with potato carboxypeptidase inhibitor. CONCLUSIONS: These data support the hypothesis that a combination of Cry3Aa protoxin and protease inhibitors, particularly a potato carboxypeptidase inhibitor, may have applications in control strategies for preventing damage to stored products and grains by coleopteran pests. Published 2011 by John Wiley & Sons, Ltd.     

谷蠹不同虫态蛀蚀对小麦成分及食用品质的影响

为研究谷蠹不同生长发育阶段侵害小麦后其成分及食用品质的变化,设定谷蠹在最适生长发育条件下（温度(32±1)℃、相对湿度75%±1%）对小麦进行侵害,测定受谷蠹卵期、幼虫期、蛹期和成虫期侵害后小麦的营养品质、流变学特性、食用品质等相关指标。结果表明：谷蠹感染小麦后,随着谷蠹在小麦籽粒内从卵生长发育到成虫阶段：灰分呈先降低后上升趋势,蛹期和成虫期与原始样间差异显著（P<0.05）;清蛋白和还原糖含量等营养指标呈现先升高后降低,清蛋白各虫期均与原始样间差异显著（P<0.05）,还原糖各虫期与原始样间无显著差异（P<0.05）;粗脂肪、谷蛋白含量逐渐降低,粗脂肪各虫期均与原始样间差异显著（P<0.05）,谷蛋白幼虫期、蛹期和成虫期与原始样间差异显著（P<0.05）;球蛋白、醇溶蛋白含量呈波动变化,球蛋白和醇溶蛋白均在幼虫期、蛹期和成虫期与原始样间差异显著（P<0.05）;另外,其微观结构显示随着谷蠹卵在小麦籽粒内生长发育,谷蠹侵害界面的质地变硬、表面粗糙、结构疏散、基质蛋白质断裂严重,且破损淀粉逐渐增多;流变学特性变化明显：出峰时间呈逐渐降低趋势,在蛹期和成虫期与原始样间差异显著（P<0.05）,峰高和峰面积先降低后升高,峰宽整体呈上升趋势,峰高、锋宽和峰值面积在各虫期间均与原始样间差异显著（P<0.05）,中线峰值右侧斜率呈先升高后降低,各虫期与原始样间差异显著（P<0.05）;馒头感官评价总分逐渐降低;全麦粉馒头质构参数中弹性、黏聚性和恢复性逐渐减小,硬度、咀嚼度、胶着性呈波动性变化。从谷蠹不同虫期感染小麦与其理化及应用品质指标间差异性分析可看出,不同虫期之间受谷蠹感染的小麦理化及应用品质指标变化显著（P<0.05）。谷蠹在幼虫期和成虫期侵害小麦后各项理化及应用品质指标变化更明显。结果表明不同虫期谷蠹对小麦蛀蚀不仅可造成理化指标的变化还可直接影响其食用品质,因此在储藏期间应注重防治不同生长期的谷蠹。