无机盐对Bt制剂防治棉铃虫的增效作用研究

在含有Ｂｔ毒素的人工饲料中分别加入Ｃａ,Ｍｇ,Ｚｎ和Ｃｕ４类盐８种化合物,进行防治棉铃虫幼虫的试验。结果表明,８个处理与单用制剂相比,毒力效价都有不同程度的提高。     

粘虫痘病毒重组增效蛋白的增效活性

采用时间—剂量—死亡率模型,分析了粘虫痘病毒(PsEPV)重组增效蛋白P39对棉铃虫核型多角体病毒(HaNPV)感染棉铃虫幼虫的增效作用.结果显示:初步纯化的P39对HaNPV感染棉铃虫3龄幼虫显示了极显著的增效活性,感染后11 d,HaNPV+P39组的LC50(1 082 PIBs/mL)比HaNPV组(13 831 PIBs/mL)降低了92.18%,增效倍数达12.8;HaNPV为1.6×103～1.6×106 PIBs/mL时,P39可缩短LT50 0.5～2.7 d.     

增效磷对农药混剂的增效作用及增效比值研究

测定增铲磷与氰戊菊酯,敌敌畏混用对褐稻虱和菜蚜的增效作用以及对其他几种害虫的增效比值结果表明,混剂对褐稻虱处理２４ｈ的触杀毒力ＬＣ５０值为１３．８５ｍｇ／ｋｇ,比单剂氰戊菊酯,敌敌畏和增效磷的触杀毒力ＬＣ５０ＷＦＨＧＯ １．１０ｍｇ／ｋｇ,比单剂氰戊菊酯,敌敌畏和增效磷的触杀毒力的分别高０．５倍,４．２倍和３２．５倍,共毒系数为２７１３５,亦有明显增效作用。     

丙溴磷防治棉铃虫的抗性风险与混配的增效作用

通过棉铃虫室内抗生选育及田间种群抗性调查,对丙溴磷的抗性风险进行了研究。结果表明：棉铃虫相对敏感种群（抗性倍数２．２）经１２代９次选育后,达到低水平抗性（６．９倍）,ＬＤ５０值比选育前提高３．０倍;田间种群抗性调查表明,山东聊城种群对丙溴磷已产生低水平的抗性,抗性倍数５．７,由此认为丙溴磷推广使用后存在明显的抗性风险。考虑到治理措施的可行性,建议用混配混用的方法来延缓抗性的发展,同时还测定了丙溴磷     

杀虫剂增效作用研究进展

讨论了杀虫剂品种间及其与增效剂、昆虫激素、植物精油混用后的增效作用研究现状，探讨了增效机制及影响因素，指出了我国对杀虫剂增作用研究应用的特点及不足。     

增效磷对农药混剂的增效作用及增效比值研究

测定增效磷与氰戊菊酯、敌敌畏混用对褐稻虱和菜蚜的增效作用以及对其他几种害虫的增效比值结果表明,混剂对褐稻虱处理２４ｈ的触杀毒力ＬＣ５０值为１３．８５ｍｇ／ｋｇ,比单剂氰戊菊酯、敌敌畏和增效磷的触杀毒力分别高６．３５倍、２．５６倍和１．８６倍,共毒系数为２３９．７５,大于２００有明显增效作用。混剂对菜蚜处理２４ｈ的触杀毒力ＬＣ５０值为１．１０ｍｇ／ｋｇ,比单剂氰戊菊酯、敌敌畏和增效磷的触杀毒力分别高０．５倍、４．２倍和３２．５倍,共毒系数为２７１．３５,亦有明显增效作用。加有增效磷的混剂对棉蚜处理２４ｈ的触杀毒力ＬＣ５０值为３０．９９ｍｇ／ｋｇ,比不加增效磷混剂的增效比值高１．７倍;对棉红叶螨处理２４ｈ的触杀毒力ＬＣ５０值为４６．５７ｍｇ／ｋｇ,增效比值为１．７倍;对玉米螟处理２４ｈ的触杀毒力ＬＣ５０值为１１６．５０ｍｇ／ｋｇ,增效比值为２．０倍;对粘虫处理２４ｈ的触杀毒力ＬＣ５０值为２４．８１ｍｇ／ｋｇ,增效比值为１．３倍。     

增效剂S2对杀虫剂增效作用研究初报

通过溴灭菊酯与S_2 1:1、1:0.7、1:0.15混配后对棉蚜、菜蚜和麦蚜的药效比较以及对棉铃虫和褐稻虱共毒系数的测定,证明其对供试害虫无增效作用;用Mansour法测定敌敌畏、混灭威、仲丁威和西维因与不同比例的S_2混配后对褐稻虱的共毒因子,表明S_2与敌敌畏1:1时,与混灭威在1:3、1:4和1:5时有增效作用,其余均不增效,说明增效剂只有使用适当,才能发挥其提高药效的功能。     

化学添加剂对Bt防治棉铃虫的增效作用

测定了 2 0种化学添加剂 ,在添加 1 .0 %的剂量下对Bt毒杀棉铃虫幼虫的增效作用。初筛和复筛结果表明 ,CuSO4( 1 .0 % )、ZnCl2 ( 1 .0 % )和硼酸等 6种物质有增效作用 ,其中CuSO4的增效作用最好 ,增效比为 1 5 .67,其次为ZnCl2 ,增效比为 1 1 .2。     

杀虫剂增效作用研究进展

讨论了杀虫剂品种间及其与增效剂、昆虫激素、植物精油混用后的增效作用研究现状，探讨了增效机制及影响因素，指出了我国对杀虫剂增效作用研究应用的特点及不足。     

丙溴磷与甲胺磷混配对棉铃虫增效作用研究

室内增效和药效试验结果表明：丙溴磷对棉铃虫幼虫具有很高的生物活性。与甲胺磷混配对棉铃虫具有一定的增效作用，以１∶６．２５配比增效最为显著，增效效果达１９．１％；混配成的４５％申丙磷制剂对棉铃虫３龄幼虫的共毒系数为１５８．４，温室盆栽棉苗药效好于５０％甲胺磷，与４０％丙溴磷防效接近。     

棉铃虫卵空间分布的地理统计学分析

调查了低密度下棉田2代棉铃虫卵的空间特性，建立了东西和南北两个方向多个变异曲线球面模型，其中大部分表现为纯块金效应；棉铃虫卵的空间变程为4.0-6.4m，空间不连续性强度为0.871-0.999。     

转Bt基因棉与常规棉的棉铃虫发生特点

比较研究了转Bt基因棉保铃棉、中棉30与棉常规品种防治和不防治情况下棉铃虫的发生特点。结果表明:(1)各处理间棉铃虫卵的发生时期基本一致,发生量则差异较大;(2)转Bt基因棉棉铃虫幼虫的发生量远低于常规棉(平均低72.4%);(3)在生长前期各处理均有一定数量的天敌类群,对棉铃虫的发生具有较好的控制作用。     

棉铃虫对苏云金杆菌(B.t)的抗性监测及延缓抗性策略

室内采用Ｂ．ｔ连续多代汰选的棉铃虫,对Ｂ．ｔ能产生较强的抗药性,抗性倍数为２４．１３。采用浸叶法测定宿县、蒙城、安庆棉区棉铃虫对Ｂ．ｔ的抗性,结果表明：宿县、蒙城淮北棉区,棉铃虫对Ｂ．ｔ已产生早期低度抗性,抗性倍数分别为３．４１和２．５２。安庆棉区棉铃虫对Ｂ．ｔ尚未产生抗性,抗性倍数为１．３７。讨论了治理抗性的对策。     

棉铃虫成虫对几种植物挥发物的触角电位反应

测定了棉铃虫(Helicoverpaarmigera)雌蛾对几种植物挥发物的触角电位反应。结果表明 ,柠檬醛、苯乙醛、β -石竹烯和石竹烯氧化物均能引起棉铃虫雌蛾产生显著的触角电位反应 ,但以柠檬醛引起的反应最强 ;棉铃虫雌蛾对茴香醛不产生显著的反应 ;桉叶素能屏蔽棉铃虫雌蛾对气味的反应。棉铃虫雌蛾对苯乙醛的触角电位反应强度与苯乙醛的剂量成正相关 ,对 β -石竹烯的反应强度与剂量无相关性。讨论了这些化合物在棉铃虫防治中的应用     

棉铃虫室内继代饲养常见问题及对策

棉铃虫是一种危害较大的农业害虫,同时也是教学和科研中常用的实验昆虫。人工饲养过程中常因管理操作不当,使种群难以为继。本文根据多年实验室饲养棉铃虫经验,分析了继代饲养过程中常出现的问题及对策,以期为棉铃虫室内继代饲养提供参考。     

第四代棉铃虫卵在华北夏玉米田的时空分布

 １９９８～１９９９年在华北夏玉米田对穗期棉铃虫卵在不同播期玉米上时空分布进行了研究．明确了其在玉米田的产卵高峰在８月中、下旬．产卵高峰有多个．虽然在不同播期的玉米田落卵数量不同,但有相同的产卵高峰;产卵部位主要在花丝和雌穗位上的叶片叶鞘上;在早播和中播夏玉米田以散粉期落卵为最多．灌浆期次之．而晚播则以抽雄期落卵最多,散粉期次之;若落卵高峰推后,则不同播期的夏玉米上均以灌浆期落卵最多,散粉期次之;在中、晚播夏玉米田的落卵量明显高于早播,且为害明显比早播重,晚播玉米田又比中播的落卵量大。因此为害则更重。     

Efficiency of Different Methods for dsRNA Delivery in Cotton Bollworm (Helicoverpa armigera)

RNAi trigged by dsRNA not only facilitates the development of molecular biology, but also initiates a new way for pest control by silence of fatal genes. However, one of the key limitations in pest control is lack of the convenient and efficient method for dsRNA delivery. In this study, different dsRNA delivery methods at their own optimum conditions were evaluated comparatively for their efficiency with Helicoverpa armigera as test animal. It was found that the popular one- time injection of larvae with dsRNA could reduce the pupation rate by 43.0% and enhance larva mortality by 11.7%. One- time ingestion of dsRNA did not result in any significant effect on phenotype. Continuous ingestion of in vitro synthesized dsRNA by refreshing the bait diet every day caused 40.4% decrease in successful pupation and 10.0% increase in larval mortality, which was similar as one-time injection. The most efficient method was found to be the continuous ingestion of the bacteria containing dsRNA expressed, which reduced the rate of pupation by 68.7% and enhanced the larval mortality by 34.1%. Further analysis found that dsRNA was degraded faster in midgut juice than in hemolymph. However, the cell of bacteria could protect dsRNA and delay the degradation in the midgut juice of H. armigera. These results throw light on the application of dsRNA in pest management with proper ways.     

Efficiency of Different Methods for dsRNA Delivery in Cotton Bollworm （Helicoverpa armigera）

RNAi trigged by dsRNA not only facilitates the development of molecular biology, but also initiates a new way for pest control by silence of fatal genes. However, one of the key limitations in pest control is lack of the convenient and efficient method for dsRNA delivery. In this study, different dsRNA delivery methods at their own optimum conditions were evaluated comparatively for their efficiency with Helicoverpa armigera as test animal. It was found that the popular one- time injection of larvae with dsRNA could reduce the pupation rate by 43.0% and enhance larva mortality by 11.7%. One- time ingestion of dsRNA did not result in any significant effect on phenotype. Continuous ingestion of in vitro synthesized dsRNA by refreshing the bait diet every day caused 40.4% decrease in successful pupation and 10.0% increase in larval mortality, which was similar as one-time injection. The most efficient method was found to be the continuous ingestion of the bacteria containing dsRNA expressed, which reduced the rate of pupation by 68.7% and enhanced the larval mortality by 34.1%. Further analysis found that dsRNA was degraded faster in midgut juice than in hemolymph. However, the cell of bacteria could protect dsRNA and delay the degradation in the midgut juice of H. armigera. These results throw light on the application of dsRNA in pest management with proper ways.     

用选择性嗅觉仪测定棉铃虫对植物气味反应的研究

发展了一种选择性嗅觉仪 ,用这种嗅觉仪测定了棉铃虫成虫对萎蔫的枫杨叶、新鲜的棉花叶、棉花花蕾、玉米叶及玉米花丝气味的反应。结果表明 :萎蔫的枫杨叶的气味对棉铃虫处女雌蛾具有引诱作用 ,对雄蛾和已交配过的雌蛾无引诱作用 ;棉铃虫雌、雄蛾不受新鲜棉花气味的引诱 ;玉米叶的气味对棉铃虫成虫无引诱作用 ,但玉米花丝对棉铃虫处女雌蛾具有较强的引诱作用。讨论了生测方法在研究昆虫与植物气味关系中的作用以及萎蔫的枫杨叶气味引诱棉铃虫的生物学意义