不同农药防治甜玉米草地贪夜蛾的药效对比试验

采用浸叶法和试验田法对五种常见的化学杀虫剂对草地贪夜蛾毒力进行了研究,并对试验数据进行处理。结果表明,浸叶法试验中,所选的五种农药都能够对草地贪夜蛾产生较大的杀灭毒力;试验田法中,3%甲维盐杀虫剂、氯虫苯甲酰胺和甲维·虫螨腈这三种杀虫剂对于草地贪夜蛾的杀灭效果最强,14 d后防效都达到86%以上;敌敌畏和虱螨脲悬浮剂(SC)的毒杀能力相对较弱,防效分别仅为56%和32%。     

玉米田草地贪夜蛾防治药剂筛选

为科学有效防控玉米田草地贪夜蛾为害,选用2.3%甲氨基阿维菌素苯甲酸盐、10%虫螨腈、5%高效氯氟氰菊酯进行药效试验,评价不同药剂防治草地贪夜蛾的效果及对作物的安全性。结果表明,2.3%甲氨基阿维菌素苯甲酸盐1 000倍液、10%虫螨腈1 600倍液能有效防治草地贪夜蛾,可及时控制其为害且药效持久。施药时间最好选择在清晨或者傍晚,避免高温施药,并注意喷洒到玉米心叶,即草地贪夜蛾为害的关键部位。     

特福力防治柑橘吹绵蚧田间防效试验初报

为探究特福力对柑橘吹绵蚧的防治效果,在田间进行防效试验。试验结果表明,特福力(22%氟啶虫胺腈悬浮剂)4 000倍液、5 000倍液2种剂量处理对柑橘吹绵蚧若虫具有良好防治效果,施药后21～28 d的防治效果极显著高于对照药剂乐斯本(48%毒死蜱乳油)1 000倍液剂量处理,且持效性长,能有效控制当代吹绵蚧的为害。特福力是一种毒性较低的农药,生产上推荐其4 000倍液在吹绵蚧低龄若虫期施药防治,可以作为低毒性柑橘吹绵蚧防治药剂加以推广应用。     

4种复配杀菌剂对设施葡萄主要病害的防效

在古浪县井河灌区试验观察了25%阿米西达悬浮剂分别与4种杀菌剂混合后,对日光温室葡萄霜霉病、灰霉病、白粉病的田间防效。结果表明,25%阿米西达悬浮剂1 500倍液+25%吡唑醚菌酯乳油3 500倍液的平均防效为93.52%,折合产量60 503 kg/hm2,较CK增产8 333 kg/hm2;其次是25%阿米西达悬浮剂1 500倍液+10%世高水分散粒剂2 000倍液的平均防效为91.53%,折合产量58 420 kg/hm2,较CK增产6 250 kg/hm2。且2种混合药剂均未发生药害,可在生产中推广。     

衡南县草地贪夜蛾发生为害特征和监测防控技术探讨

草地贪夜蛾是一种跨境迁飞性重大害虫,具有寄主范围广、繁殖能力强、迁飞扩散快、为害程度重和防控难度大的特点。基于此,阐述了草地贪夜蛾在湖南省衡南县的发生为害特征,提出了监测预报、间作套种、种子处理、理化诱控、生物防治和应急化防等配套技术措施,采用联防联控、群防群治和统防统治等手段,确保好的防效和粮食生产安全。     

五种杀虫剂防治榨菜小菜蛾的药效试验初报

比较了1.0%甲氨基阿维菌素苯甲酸盐乳油、10%虫螨腈悬浮剂(除尽)、0.5%烟碱·苦参碱水剂、5%氟啶脲乳油(抑太保)和20%甲氧虫酰肼悬浮剂(美满)5中杀虫剂防治榨菜小菜蛾的防效,结果表明20%甲氧虫酰肼悬浮剂(美满)防治效果最好,其次为5%氟啶脲乳油(抑太保)。     

4种药剂对大樱桃叶螨的田间防效

进行了15 %阿维·毒死蜱悬浮剂、4%阿维·吡虫啉乳油、5%高效氯氟氰菊酯水乳剂和6%高氯·甲维盐微乳剂4种药剂对大樱桃叶螨的田间防效试验。结果表明,以15 %阿维·毒死蜱悬浮剂2 000 mg/kg处理防治效果最好,第1次施药后5 d的防效为87.45%,第2次施药后7 d的防效为96.43%,其两次施药后对大樱桃叶螨的防效均优于其余3种药剂处理,且无药害,生产上可用于大樱桃叶螨的田间防治。     

不同药剂处理对制种玉米叶螨的防效

在张掖市制种玉米田试验观察了不同药剂处理对玉米叶螨的防治效果,结果表明,各处理药后3、7、14 d的防效都达到84%以上,其中以500 g/L力满星(溴螨酯)乳油300 mL/hm2+5%替满松(噻螨酮)乳油450 mL/hm2处理的防治效果最好,药后3、7、14 d的防效分别为87.31%、88.80%、89.31%。10%四螨·三唑锡悬浮剂300 mL/hm2、10%阿维·哒螨灵乳油300 mL/hm2、20.8%阿维·四螨嗪悬浮剂450 mL/hm2等3个处理的防效也较好,但略低于前者。4个药剂处理均无药害现象发生,对作物安全。建议在6月中旬至8月上旬根据张掖玉米制种田叶螨发生程度,及时选用10%四螨·三唑锡悬浮剂、500 g/L溴螨酯(力满星)乳油+5%噻螨酮(替满松)乳油、10%阿维·哒螨灵乳油、20.8%阿维·四螨嗪悬浮剂等药剂轮换交替喷雾防治。     

两种不同剂型毒死蜱对四种环境生物的毒性评价

按照化学农药环境安全评价试验准则方法,测定了40%毒死蜱乳油和30%毒死蜱微囊悬浮剂对鱼类、鸟类、家蚕和蜜蜂4种环境生物的毒性。结果表明,毒死蜱乳油对斑马鱼LC50值（96 h）为0.68 mg.L^-1,毒死蜱微囊悬浮剂的LC50为47.30 mg.L^-1;毒死蜱乳油对鹌鹑的毒性LD50为7.45 mg.kg^-1,毒死蜱微囊悬浮剂的LD50为56.97 mg.kg^-1。食下毒叶法结果表明,毒死蜱乳油对2-4龄家蚕幼虫LC50值（48 h,25℃）分别为0.82、1.87 mg.L^-1与4.35 mg.L^-1,毒死蜱微囊悬浮剂为2.48、4.22 mg.L-1与8.35 mg.L^-1;家蚕幼虫在药膜上爬行1、10、30 min与60 min后,毒死蜱乳油对3龄家蚕幼虫的LD50值（48 h,25℃）分别为3.18、0.68、0.41μg.cm^-2与0.38μg.cm^-2,其微囊悬浮剂LD50值分别为6.92、1.58、1.18μg.cm^-2与0.48μg.cm^-2;毒死蜱乳油和微囊悬浮剂对蜜蜂48 h的LC50分别为0.53 mg.L^-1和2.32 mg.L^-1。上述结果表明,毒死蜱微囊悬浮剂对4种环境生物的安全性明显高于乳油。     

不同药剂防治柑橘溃疡病的田间药效对比试验

为研究不同药剂防治柑橘溃疡病的药效,进行了田间药效对比试验。结果表明,在用药15 d后,20%噻菌铜悬浮剂500倍液对于柑橘溃疡病有着良好的防治效果,防效可以达到86.17%,对比77%氯氧化铜可湿性粉剂500倍液、20%噻森铜悬浮剂500倍液、47%春雷·王铜可湿性粉剂500倍液,防效较高,而且具有低毒低残留的特点,是一种理想的柑橘溃疡病防治药剂。     

虫害诱导烟草抗性对斜纹夜蛾取食及解毒酶的影响

为探究不同虫害诱导抗性烟草(Nicotiana tabacum L.)对斜纹夜蛾(Spodoptera litura Fabricius)取食和解毒生理的影响,本研究以烤烟品种雄性不育K326为供试材料,观察斜纹夜蛾幼虫对棉铃虫[Helicoverpa armigera(Hübner)]诱导烟草、斜纹夜蛾诱导烟草、烟蚜...     

杠柳根皮粗提液对菜青虫生物活性的影响

试验研究杠柳根皮粗提液对菜青虫生物活性的影响测定结果表明,杠柳根皮乙醇提取液对菜青虫的生物活性影响高于杠柳根皮氯仿提取液和石油醚提取液,杠柳根皮乙醇提取液对菜青虫幼虫有较强的拒食作用和生长抑制作用,胃毒作用一般。用100倍液杠柳根皮乙醇提取液浸叶饲喂3龄、4龄、5龄菜青虫幼虫后24h其拒食率分别为94.9%、87.8%和92.7%,拒食后幼虫的化蛹率和蛹重均比对照显著降低。100倍液杠柳根皮乙醇提取液浸叶饲喂4龄菜青虫幼虫后24h和72h其生长抑制率分别为96.6%和82.5%。杠柳根皮乙醇提取液对菜青虫成虫产卵具有明显忌避作用,用50~100倍液杠柳根皮乙醇提取液喷雾处理油菜苗后2~4d其产卵忌避率达89.5%以上。     

蓖麻叶片粗提物对黄瓜瓜绢螟的作用

为了测定蓖麻对瓜绢螟的作用,也为黄瓜害虫无公害控制提供新的手段,用不同浓度的蓖麻叶片粗提物处理黄瓜叶片,测定瓜绢螟取食量、存活率及体内解毒酶活性的变化。结果显示,蓖麻叶片粗提物对瓜绢螟的取食和存活有明显的抑制作用,处理浓度越大,取食量和存活率越小。如用稀释200倍的蓖麻叶片粗提液处理黄瓜叶片,瓜绢螟的取食面积(1.89 cm2)仅为对照(3.51 cm2)的53.7%,存活率为对照的2.3%;600倍浸提液处理的瓜绢螟取食面积(3.43 cm2)为对照的97.7%,存活率为对照的51.4%。瓜绢螟幼虫虫龄对粗提物的作用有明显影响,粗提物对低龄幼虫的作用明显强于高龄幼虫,200倍液处理24 h后,1龄幼虫的存活率(22.22%)仅为5龄幼虫(66.67%)的33.33%。不同剂量蓖麻叶片粗提物处理后,瓜绢螟体内的谷胱甘肽转移酶、羧酸脂酶、多功能氧化酶等解毒酶活性迅速上升,随着处理剂量的增加,解毒酶的活性上升幅度增大。取食用稀释200倍的蓖麻粗提液处理的黄瓜叶片24 h后,1龄幼虫和5龄幼虫体内谷胱甘肽转移酶活性分别较对照高23.79%和78.02%,羧酸脂酶活性分别较对照高72.42%和23.84%,多功能氧化酶活性分别较对照高100.58%和122.39%。结果表明,蓖麻叶片粗提物对瓜绢螟有明显的拒食和毒杀作用。     

AcMNPV chiA基因表达产物对棉铃虫围食膜的破坏及对Bt和NPV的增效作用

采用PCR方法扩增出苜蓿银纹夜蛾(Autographa californica)核型多角体病毒(AcMNPV)几丁质酶基因(chiA)编码区1.6kb全长片段,并将该片段分别克隆至原核表达载体pET30a和杆状病毒BactoBac表达系统转移载体pFastBac中,分别在大肠杆菌(Escherichia coli)BL21(DE3)和草地贪夜蛾(Spodoptera frugiperda)细胞系Sf-9中进行了表达。SDS-PAGE分析表明,在大肠杆菌和昆虫细胞中均有效表达了60kD的蛋白。将表达产物饲喂5龄棉铃虫(Helicoverpa armigera)幼虫后取其围食膜,扫描电镜结果显示,围食膜结构遭到破坏形成大量孔洞。生物测定结果表明,以上两种表达产物对苏云金芽孢杆菌(Bt)和核型多角体病毒(NPV)均具有增效作用。以AcMNPVChiA在大肠杆菌和细胞系Sf-9中的表达产物分别与BtCry2Ac蛋白混合饲喂棉铃虫初孵幼虫,增效率分别为33.4%和54.5%,其LT50较对照处理分别缩短了17.8和20.6h;当AcMNPVChiA在大肠杆菌和细胞系Sf-9中的表达产物分别与甘蓝夜蛾(Mamestra brassica)核型多角体病毒(MbNPV)混合处理棉铃虫初孵幼虫时,其LT50与对照比较分别缩短了16.6和22.4h。     

AcMNPV chiA基因表达产物对棉铃虫围食膜的破坏及对Bt和NPV的增效作用研究

采用PCR方法扩增出苜蓿银纹夜蛾核型多角体病毒（AcMNPV）几丁质酶基因（chiA）编码区1.6kb全长片段,并将该片段分别克隆至原核表达载体pET30a和杆状病毒Bac to Bac表达系统转移载体pFastBac中,分别在大肠杆菌（E. coli）BL21(DE3)和草地贪夜蛾细胞系Sf-9中进行了表达。SDS-PAGE分析表明,在大肠杆菌和昆虫细胞中均有效表达了60kDa的蛋白。将表达产物饲喂5龄棉铃虫幼虫后取其围食膜,扫描电镜结果显示,围食膜结构遭到破坏形成大量孔洞。生物测定结果表明,以上两种表达产物对Bt和NPV均具有增效作用。以AcMNPV ChiA在大肠杆菌和细胞系Sf-9中的表达产物分别与Bt Cry2Ac蛋白混合饲喂棉铃虫幼虫,增效率分别为33.4％和54.5％,其LT50较对照处理分别缩短了17.8h和20.6h;当AcMNPV ChiA在大肠杆菌和细胞系Sf-9中的表达产物分别与甘蓝夜蛾核型多角体病毒（MbNPV）混合处理棉铃虫幼虫时,其LT50与对照比较分别缩短了16.6h和22.4h。     

Screening of dialkoxybenzenes and disubstituted cyclopentene derivatives against the cabbage looper, Trichoplusia ni, for the discovery of new feeding and oviposition deterrents

The antifeedant, oviposition deterrent, and toxic effects of dialkoxybenzene minilibraries and of disubstituted cyclopentene minilibraries (i.e., consisting of four to five compounds) along with their pure constituent compounds were assessed against third instar larvae and adults of the cabbage looper, Trichoplusia ni, in laboratory bioassays in a search for new insect control agents. These compounds mimic naturally occurring bioactive odorants and tastants and are relatively easily prepared from commodity chemicals. Most of these libraries strongly deterred larval feeding, with some exhibiting strong toxic and oviposition deterrent effects as well. Our results suggest some structure-function relationships within these libraries. Replacement of a methyl group with larger alkyl substituents increased the feeding deterrent effects in most cases. The presence of a free hydroxyl group, irrespective of the carbon framework or alkyl substituent, served to reduce feeding deterrent effects in all series of compounds. Further, exceeding a certain group size also generally had a detrimental effect. This information will be useful in designing new insect control agents for agriculture. Some of these libraries and compounds may have potential for development as commercial insecticides.     

Toxicity of selected biorational insecticides to Pulvinaria aurantii Cockerell and its predator,Cryptolaemus montrouzieri Mulsant in citrus field

The citrus cottony scale, Pulvinaria aurantii Cockerell, is the most important pest of citrus orchards in northern Iran in recent years. Owing to the harmful impacts of chemical insecticides, the use of biorational pesticides seems a safe and convenient way to control this pest. The present investigation was set up to study contact toxicity of various biorational and chemical compounds on the first, second instar nymph and overwintering adult of the citrus cottony scale, P. aurantii, and its predator, Cryptolaemus montrouzieri Mulsant under field conditions. The results indicated that the highest percentage of mortality of first instar nymph of the citrus cottony scale was observed in the Dayabon treatment of 9 and 10?ml/L, 100.0%?±?0.0% and the lowest percentage was observed in Palizin treatment of 1.5?ml/L, 34.7%?±?2.9%. In the second instar nymph, the highest mortality was seen in the Dursban treatment of 2?ml/L, 94.7%?±?2.4% and the lowest mortality in the Palizin treatment of 1.5?ml/L, 30.0%?±?2.3%. Also, for overwintering adults Dayabon 10?ml/L caused the highest mortality, 96.0%?±?4.0% during 24?h. In the case of ladybird insects, the highest and lowest percentage of mortality was observed in the Dursban treatment of 2?ml/L, 76.7%?±?8.8%, Dayabon 5?ml/L, and Palizin 2?ml/L, 3.3%?±?3.3%, respectively. The highest and lowest mortality rate of larvae of ladybird was estimated in the Dursban treatment of 2?ml/L, 83.3%?±?3.3% and Dayabon 5?ml/L, 3.3%?±?3.3%, respectively. Also, for overwintering predator adults Palizin 1.5?ml/L had the lowest mortality, 3.3%?±?3.3% during 24?h and this rate remain unchanged after 96?h after treatment. According to the results obtained, treatments with Dayabon 9 and 10?ml/L, can be a viable alternative to other high-risk chemical pesticides in addition to effectively controlling citrus cottony scale without having any adverse impacts on predator ladybird.     

Oral toxicity of beta-N-acetyl hexosaminidase to insects

Insect chitin is a potential target for resistance plant proteins, but plant-derived chitin-degrading enzymes active against insects are virtually unknown. Commercial beta-N-acetylhexosaminidase (NAHA), a chitin-degrading enzyme from jack bean Canavalia ensiformis, caused significant mortality of fall armyworm Spodoptera frugiperda larvae at 75 microg/gm, but no significant mortality was noted with Aspergillus niger NAHA. Maize Zea mays callus transformed to express an Arabidopsis thaliana clone that putatively codes for NAHA caused significantly higher mortality of cigarette beetle Lasioderma serricorne larvae and significantly reduced growth rates (as reflected by survivor weights) of S. frugiperda as compared to callus that expressed control cDNAs. Tassels from model line Hi-II maize (Z. mays) plants transformed with the NAHA gene fed to S. frugiperda caused significantly higher mortality than tassels transformed to express glucuronidase; mortality was significantly correlated with NAHA expression levels detected histochemically. Leaf disks from inbred Oh43 maize plants transformed with the NAHA gene on average had significantly less feeding by caterpillars than null transformants. Leaf disks of Oh43 transformants caused significant mortality of both S. frugiperda and corn earworm Helicoverpa zea larvae, which was associated with higher expression levels of NAHA detected by isoelectric focusing, histochemically, or with antibody. Overall, these results suggest that plant NAHA has a role in insect resistance. Introduction of NAHA genes or enhancement of activity through breeding or genetic engineering has the potential to significantly reduce insect damage and thereby indirectly reduce mycotoxins that are harmful to animals and people.