吡虫啉对意大利蜜蜂乙酰胆碱酯酶的亚致死效应

【目的】确定吡虫啉对意大利蜜蜂Apis mellifera的致死中浓度,探究吡虫啉对意大利蜜蜂乙酰胆碱酯酶的亚致死效应。【方法】本文采用药膜法、点滴法和饲喂法测定吡虫啉对意大利蜜蜂的毒力曲线,及蜜蜂接触吡虫啉后头部乙酰胆碱酯酶活性的变化。应用RT-q PCR技术研究饲喂LC5浓度吡虫啉后,蜜蜂乙酰胆碱酯酶基因Ace1和Ace2的m RNA相对表达量。【结果】饲喂法、点滴法和药膜法3种方法测定的吡虫啉对意大利蜜蜂的致死中浓度分别是7.15 mg/L、0.078 ng/蜂和51 ng/cm2。3种作用方式下,吡虫啉均抑制了乙酰胆碱酯酶活性;随着浓度增加,ACh E酶活性处于下降状态,但降低较少。LC5浓度的吡虫啉对蜜蜂ACh E活性具有明显影响,24 h内ACh E活性呈现增强-抑制-增强的趋势。饲喂蜜蜂LC5亚致死浓度的吡虫啉后,Ace1和Ace2被诱导表达,但在1、2和16 h与对照无明显差异。【结论】亚致死浓度的吡虫啉对蜜蜂乙酰胆碱酯活性具有抑制作用,并且存在明显的剂量效应和时间效应,对Ace1和Ace2具有诱导效应,酶活性水平和m RNA相对表达水平不一致。     

亚致死剂量杀虫剂对异色瓢虫捕食作用的影响

为探讨害虫化学防治与生物防治的协调技术,提高综合防治水平,测定了吡虫啉,鱼藤酮,氰戊菊酯和阿维菌素A种杀虫剂亚致死剂量对异色瓢虫成虫捕食桃蚜功能反应的影响。亚致死剂量杀虫剂对异色瓢虫功能反应模型的基本结构没有改变,但影响到了模型的各项参数,药剂处理后异色瓢虫最大日捕食量降低,处理猎物的时间延长,捕食速率和寻找效应一般也被减弱,影响结果还与异色瓢虫受药的方式有关,4种药剂中以氰戊菊酯的影响最大,鱼藤酮的胃毒作用也较明显,研究结果表明亚致死剂量的杀虫剂对天敌异色瓢虫的捕食作用存在着不良影响,这为害虫治理中如何协调利用化学防治和生物防治措施,指导科学用药提供了一定的理论基础。     

亚致死剂量的多杀菌素对棉铃虫生长发育的影响

多杀菌素（spinosad）是一种土壤放线菌产生的大环内酯类化合物,因其具有低毒、低残留、对天敌昆虫安全但对多种重要害虫高杀虫活性的特点,被广泛用于多种害虫的防治。目前,在亚致死剂量下多杀菌素对重要害虫棉铃虫的作用还不清楚。     

松墨天牛幼虫体内神经毒性酯酶和乙酰胆碱酯酶对甲胺磷敏感性的比较

松墨天牛Monochamus alternatus Hope是传播松材线虫Bursaphelenchus xylophilus Nickle的主要媒介昆虫,在其化学防治中经常使用有机磷杀虫剂,而这类杀虫剂有些可通过作用于神经毒性酯酶（neurotoxic esterase, NTE）使敏感的脊椎动物产生迟发性神经毒性。为了深入理解有机磷杀虫剂对害虫毒杀作用机理,增强对昆虫体内NTE活性的了解,我们在松墨天牛中开展了相关的研究。通过差异测定法和经典的乙酰胆碱酯酶（acetylcholinesterase, AChE）活性测定方法,分别测定了松墨天牛幼虫体内NTE和AChE的活性。结果发现,在松墨天牛体内存在NTE活性,其头部的NTE活力为2.80±0.30 nmol·min^-1·mg^-1,比脂肪体高出了近10倍,但仍较鸟类等脊椎动物为低。体内实验显示,松墨天牛体内NTE可被甲胺磷所抑制; 但在体外实验条件下,甲胺磷对来自松墨天牛头部的NTE活性并没有产生明显抑制作用,而此浓度下的甲胺磷对AChE表现出较高水平的抑制作用。表明松墨天牛体内NTE和AChE对甲胺磷的敏感性完全不同。     

原子力显微观察巯基反应剂对乙酰胆碱酯酶立体结构的影响

目的:研究巯基及二硫键对乙酰胆碱酯酶(AChE)高级结构的作用。方法:将与巯基反应剂GSH和DTT作用前后的AChE重组到磷脂膜上,置于原子力显微镜下观察,扫描方式为空气中接触模式。结果:天然的AChE直径不均一,既有大粒子也有小粒子,平均最大直径(95±44)nm,平均半径(43±17)nm,平均高度(9.25±2.62)nm;与GSH反应后的AChE整体粒径明显变小,最大直径(31±13)nm,平均半径(15±4)nm,平均高度(4.02±0.67)nm;与DTT反应后的AChE边界模糊。结论:GSH可将AChE多聚体还原为单体;相同浓度的DTT作用不明显。     

啶虫脒对淡色库蚊幼虫的致死和亚致死影响

啶虫脒是日本曹达公司新开发的一种氯代烟碱类杀虫剂,为了探讨其用于蚊虫幼虫控制的可能性,我们在室内用浸渍法测定了啶虫脒对淡色库蚊幼虫的致死和亚致死影响,结果表明,淡色库蚊幼虫对啶虫脒较敏感,幼虫的死亡高峰出现在处理后第3天,幼虫的四个龄期中,一龄最敏感,四龄耐药力最强,二在处理后72h时的LC50值分别为0.020mg/L/升和0.296mg/L。幼虫在亚致死浓度的啶虫脒溶液作用下,发育期延长,蛹重下降。说明啶虫脒可用于蚊虫幼虫的控制。     

棉铃虫乙酰胆碱酯酶(AChE)的体躯分布及部分纯化

该文研究了棉铃虫Helicoverpa armigera乙酰胆碱酯酶(AChE)的体躯分布及部分纯化技术。在幼虫和成虫体内均以头部AChE活性最高;AChE在成虫和幼虫头、胸、腹部的活性分布分别为78.2%、3.9%、17.9%和90.3%、6.5%和3.2%。通过用Sepharose 4B和Sephadex G-200纯化后,AChE的最高纯化倍数为3.66和17.74倍。样品和洗脱液中含有Triton X-100时,纯化倍数明显高于无Triton X-100的处理组。     

毒死蜱亚致死剂量对灰飞虱致害性和繁殖力的影响

为科学用药防治灰飞虱Laodelphax striatellus (Fallén)提供理论依据, 采用麦秆浸渍法测定毒死蜱对灰飞虱成虫的室内活性, 并用Parafilm小袋法和滤纸漏斗法测定毒死蜱亚致死剂量对灰飞虱蜜露排泄量、 虫体增重、 产卵量等指标的影响。Parafilm小袋法的测定结果表明, 经毒死蜱亚致死剂量（0.21 mg/L有效成分）处理的灰飞虱单雌蜜露分泌量和虫体增重分别比对照增加10.99%和22.22%, 但与对照相比无显著差异（P>0.05）; 单雌产卵量为79.6±26.4个, 比对照增加12.27%, 差异达到极显著水平（P<0.01）。滤纸漏斗法的测定结果表明, 处理过的灰飞虱雌成虫蜜露分泌面积为119.74±5.90 mm², 比对照增加13.06%, 差异达到显著水平（P<0.05）。毒死蜱亚致死剂量处理后对灰飞虱蜜露分泌量、 虫体增重和单雌产卵量均表现不同程度的促进作用, 说明毒死蜱亚致死剂量可能会导致灰飞虱致害性加剧。本研究结果对深入研究杀虫剂对灰飞虱种群的亚致死效应具有重要的参考价值。     

亚致死剂量毒死蜱对飞蝗细胞色素P450酶活性及基因表达的影响

【目的】研究有机磷杀虫剂毒死蜱对飞蝗体内细胞色素P450的影响。【方法】采用酶活力测定法和实时定量PCR技术分别研究了毒死蜱3种亚致死剂量(LD_(10)、LD_(30)和LD_(50))处理飞蝗3龄幼虫24 h后,体内细胞色素P450酶活性及CYP409A1和CYP408B1基因表达量的变化。【结果】不同亚致死剂量毒死蜱处理引起细胞色素P450活性显著性降低,分别为对照组的0.68、0.50和0.62倍。同时通过mRNA水平表达的差异比较显示,飞蝗的两个P450基因CYP409A1和CYP408B1的表达受到抑制,均出现表达量减少的现象。【结论】某些细胞色素P450基因表达受不同亚致死剂量毒死蜱的抑制而使酶的量被降低,从而造成飞蝗整体细胞色素P450酶活性的下降。     

双酰胺类杀虫剂对棉铃虫和松毛虫赤眼蜂的选择毒力

为了指导棉铃虫防控中化学杀虫剂和天敌昆虫协调使用,本文采用浸叶法和玻管药膜法测定了4种双酰胺类杀虫剂对棉铃虫3龄幼虫和松毛虫赤眼蜂成蜂的毒力.结果表明,供试双酰胺类杀虫剂中氯虫苯甲酰胺、氟苯虫酰胺和氟氰虫酰胺对棉铃虫幼虫表现出了较高的毒力水平(LC50分别为0.2882、0.3894、0.8609 mg/L),稍低于对照药剂甲氨基阿维菌素苯甲酸盐(简称:甲维盐)(LC50为0.06493 mg/L);而溴氰虫酰胺对棉铃虫的毒力(LC50为3.7638 mg/L)明显低于甲维盐.从对天敌昆虫安全性来看,氯虫苯甲酰胺、氟苯虫酰胺和氟氰虫酰胺对松毛虫赤眼蜂的毒性(LC50分别为1.0060、0.9933、1.1541 mg/L)明显低于甲维盐(其LC50为0.1646 mg/L),表现出了较高的安全性;但是,溴氰虫酰胺对松毛虫赤眼蜂毒性较高(LC50为0.4952 mg/L),安全性较差.本研究将为棉铃虫防控中药剂与天敌协调使用提供依据.     

Lethal and sublethal effects of thiacloprid on survival,growth and reproduction of Helicoverpa armigera (Lepidoptera: Noctuidae)

The cotton bollworm Helicoverpa armigera (Hübner) is the most destructive pest of cotton, tomato and chickpea in Iran. In this study, the lethal and sublethal effects of thiacloprid were evaluated against cotton bollworm under laboratory condition at 26?±?1?°C, 70?±?5% RH and a photoperiod of 16:8 (L:D). Bioassay experiments were conducted on first larval instars by mixing the insecticide dilutions with artificial diet. The LC₅₀ value of thiacloprid was 329?mg a.i./l. Sublethal effects of LC₃₀ concentration of thiacloprid was studied on biological parameters. In the study of sublethal effects, thiacloprid at LC₃₀ concentration significantly increased larval and pupal developmental times and reduced adults longevity compared with control but showed no significant effects on fecundity of cotton bollworm. Sublethal effects of thiacloprid also significantly reduced pupal weight compared with control. In general, sublethal effects studies showed that thiacloprid had adverse effects on biological parameters of the pest. Thus, our data suggest that thiacloprid had moderate potential against cotton bollworm.     

Baseline toxicity of emamectin and spinosad to Helicoverpa armigera (Lepidoptera: Noctuidae) for resistance monitoring

Acute toxicity studies of emamectin and spinosad against Helicoverpa armigera revealed that the pest is highly susceptible to both the insecticides. The median lethal dose (LD₅₀) of emamectin is 3.86 × 10⁻³ µg per larva. The median lethal concentrations (LC₅₀) of emamectin and spinosad were found to be 0.09 and 2.94 ppm, respectively. The discriminating doses were fixed based on the LC₉₅ of the susceptible population of H. armigera as 0.80 ppm for emamectin and 10 ppm for spinosad. Resistance was not observed when the discriminating doses of emamectin and spinosad were applied on field-collected populations of H. armigera from two intensive cotton growing areas, Coimbatore and Madurai, India.     

Influences of insecticides on toxicity and cuticular penetration of abamectin in Helicoverpa armigera

Synergistic actions for mixtures of abamectin with other insecticides in some insect pests were evaluated, and the possible synergistic mechanism was studied by the comparison in toxicity and cuticular penetration of abamectin between with and without other insecticides or synergists in Helicoverpa armigera larvae. The results of bioassay showed that horticultural mineral oil (HMO), hexaflumuron, chlorpyrifos, and some other insecticides were synergistic to abamectin with 152.0-420.0 of co-toxicity coefficient(CTC) in some agricultural insect pests. In topical application tests, HMO or piperonyl butoxide (PBO) increased the toxicity of abamectin in larvae of H. armigera, but the mortality was not affected by s,s,s-tributylphorotrithioate (DEF) and triphenylphosphate (TPP). The synergistic action of HMO was obviously higher than PBO, and when treated simultaneously with abamectin, HMO gave a more significant synergism than if treated 2 hours ahead. The highest synergistic effect (SE) was found in the mixture of ‘abamectin HMO (1:206)‘. The mortality did not increase or the toxicity drop, when a synergist or HMO was added into the mixture of ‘abamectin HMO‘ or ‘abamectin synergist‘, respectively. Results from the isotope tracing experiments showed that HMO significantly enhanced the penetration of ^3H-abamectin through the cuticle of H.armigera larvae, which resulted in the synergism of the mixture. The cuticular penetration of ^3H-abamectin was not accumulatively affected by chlorpyrifos, nor by hexaflumuron,though there was an inhibition within 30 seconds or 1 hour after treated by these two chemicals respectively. Results suggested that the synergism of abamectin mixed with hexaflumuron or chlorpyrifos might be related to inhibition of metabolic enzymes or target sites in the larvae.     

甲氧虫酰肼对棉铃虫生长发育的亚致死效应研究

以一个对甲氧虫酰肼具有18.5倍抗性的棉铃虫Helicoverpa armigera(Hübner)种群(R)和其同源对照种群(S)为对象,研究了甲氧虫酰肼对棉铃虫生长发育的亚致死效应。结果表明,甲氧虫酰肼亚致死剂量(LC25)处理R和S种群的3龄初幼虫,对S种群幼虫的生长抑制率(37.30%)显著大于R种群(21.20%)。与空白对照处理相比,致死剂量处理R和S种群后,均表现出生长发育延缓,蛹期延长,化蛹率、羽化率、卵孵化率降低,且对S种群的影响更明显。研究结果表明亚致死剂量的甲氧虫酰肼对棉铃虫存在一定的不利影响,但对甲氧虫酰肼具有一定抗性的棉铃虫种群能够减轻这种不利影响。     

茚虫威亚致死浓度对茚虫威敏感性降低的棉铃虫生物学参数及解毒酶活性的影响

【目的】本研究旨在明确茚虫威亚致死浓度对茚虫威敏感性降低的棉铃虫Helicoverpa armigera生物学参数及解毒酶活性的影响,以科学有效防治这一害虫,避免其对茚虫威的抗性快速发展。【方法】采用浸叶法测定了茚虫威对棉铃虫茚虫威抗性汰选种群(TP)及其同源对照种群(CP)3龄幼虫的毒力;用两性生命表分析LC₂₀浓度茚虫威对TP种群当代(F₀)生命表参数的影响,并测定了LC₂₀浓度茚虫威处理48 h后CP和TP种群棉铃虫3龄幼虫体内解毒酶［多功能氧化酶(MFO)、羧酸酯酶(CarE)和谷胱甘肽-S-转移酶(GST)］及乙酰胆碱酯酶(AChE)的活性。【结果】茚虫威对棉铃虫CP种群和TP种群3龄幼虫的LC₂₀分别为2.27和9.91 mg/L。LC₂₀茚虫威处理TP种群后,48 h的生长量、化蛹率、羽化率和成虫畸形率均显著低于未用药对照,而特定年龄生命期望值e_xj高于未用药对照;TP种群棉铃虫3龄幼虫体内GST和MFO活性与CP种群相比显著升高,CarE活性显著降低。【结论】本研究结果表明棉铃虫TP种群在LC₂₀浓度茚虫威胁迫下存在明显的生长与繁殖不利性,同时对其也产生了适应能力。LC₂₀浓度茚虫威处理后,棉铃虫TP种群的GST和MFO活性被显著诱导,说明这两种酶可能与棉铃虫对茚虫威产生抗药性密切相关;而CarE活性被显著抑制,说明该酶可能参与了茚虫威转化成N-脱甲氧羰基代谢物(DCJW)的活化过程。     

Genetics of Indoxacarb resistance in Helicoverpa armigera (Hubner)

The present investigation was done with the aim of studying the genetics of Indoxacarb resistance. Selection of Helicoverpa armigera (Hubner) with Indoxacarb was done for eight generations to develop resistance. Reciprocal crosses between resistant and susceptible populations were made to understand the population genetics of Indoxacarb resistance in H. armigera . Generation-wise selection with Indoxacarb was evaluated for resistance development in H. armigera . The LC₅₀ of Indoxacarb was 2.81 p.p.m. for the first selected generation, and it increased to 272.55 p.p.m. after eight selected generations, which is a 1238.86-fold resistance compared to the susceptible strain. The estimated realized heritability (h²) after eight generations of selection with Indoxacarb was 0.45. The number of generations required for a tenfold increase in LC₅₀ (1/R) was estimated to be 2.59. The response to Indoxacarb selection in H. armigera was 0.39, the estimated selection differential (S) was 0.87, and the phenotypic standard deviation (σp) was 0.03. Reciprocal crosses between Indoxacarb resistant and susceptible strains revealed that the inheritance of Indoxacarb resistance was autosomal: neither maternal effect nor linkage was evident. The values of D_LC (0.10 and 0.09) indicated completely recessive inheritance of Indoxacarb resistance.     

复配杀虫剂BtA对棉铃虫的杀虫效果及对天敌中红侧沟茧蜂蛹和成虫的触杀毒性(英文)

为了科学施药, 合理保护和利用天敌对棉铃虫Helicoverpa armigera进行综合防治, 本研究在室内测定和比较了复配杀虫剂BtA和7种常用杀虫剂（阿维菌素、 Bt、 β-氯氰菊酯、辛硫磷、定虫隆、氰戊菊酯和丁硫克百威）对棉铃虫的杀虫效果及对其天敌中红侧沟茧蜂Microplitis mediator蛹和雌成虫的触杀毒性。采用浸叶法测定杀虫剂在室内72 h内对棉铃虫3龄幼虫的杀虫效果, 结果表明： 与其他杀虫剂相比, BtA对棉铃虫幼虫具有更高的毒性和致死效应 (LC₅₀=0.7364 mg/mL)。将棉铃虫3龄幼虫接到用浓度4 mg/mL上述杀虫剂分别处理过的大白菜上24, 48和72 h, 发现其死亡率之间存在显著差异（P≤0.05）。但在72 h后, BtA和其他杀虫剂对棉铃虫幼虫的杀虫效果之间并无显著差异(P>0.05)。BtA施药后, 随着时间的延长, 棉铃虫幼虫的死亡率也在增加。另外, 通过杀虫剂对寄生蜂中红侧沟茧蜂蛹和雌成虫的触杀毒性的生物测定发现： 与β-氯氰菊酯、 氰戊菊酯和丁硫克百威相比, BtA对中红侧沟茧蜂蛹和雌成虫的毒性较低, 对其蛹和雌成虫致死率分别仅为13.82%和7.33%。本研究证明BtA对鳞翅目害虫具有中等毒性, 而对寄生蜂中红侧沟茧蜂则具有较低毒性。     

棉铃虫抗药性监测方法——浸叶法敏感毒力基线的建立及其应用

通过室内饲养的2个棉铃虫敏感品系,用浸叶法建立了11种常用药剂 (氯氰菊酯、溴氰菊酯、功夫菊酯、氰戊菊酯、久效磷、辛硫磷、甲基对硫磷、毒死蜱、灭多威、硫双灭多威、硫丹) 的敏感毒力基线,确定了它们的LC₅₀值和区分剂量。并用浸叶法监测了江苏、山东、河南、安徽4省棉田2代棉铃虫对氯氰菊酯、久效磷、灭多威和辛硫磷的抗性,结果表明用区分剂量监测抗性个体频率既快速简便,又适宜于进行早期抗性检测,因此这4种药剂的区分剂量可以推广应用于棉铃虫田间抗药性监测。     

棉铃虫血淋巴酚氧化酶活性的微量测定

昆虫血淋巴黑化的形成由激活酚氧化酶原的级联系统所引发 ,酚氧化酶在昆虫体液免疫中起着重要作用。用抗凝剂从棉铃虫血淋巴中分离获得了血浆及完整的血细胞 ,以L DOPA为底物 ,牛胰蛋白酶为激活剂 ,测定了血浆及血细胞裂解液中酚氧化酶及酚氧化酶原的活性。结果表明 ,血浆及血细胞中两者都有一定量的分布。这一昆虫血淋巴酚氧化酶的微量测定方法 ,所需样品量少 ,耗时短 ,简便易行。