磷化氢熏蒸处理对嗜卷书虱不同虫态的致死作用

实验室条件下系统研究了磷化氢(PH3)对储物害虫嗜卷书虱Liposcelis bostrychophila卵、各龄若虫和成虫的致死作用,并选用PH3间歇熏蒸以及PH3与气调交替处理等措施对嗜卷书虱进行处理,比较了不同处理措施对嗜卷书虱种群的控制效果。结果表明,PH3熏蒸处理对嗜卷书虱各虫态有不同的致死效果。对卵而言,24、72和120 h熏蒸处理的LC50分别为0.137、0.045和0.035 mg/L;而24 h熏蒸处理对若虫的LC50在4.285~7.364 μg/L之间,对成虫的LC50为20.404 μg/L;采用25 μg/L的PH3进行24 h熏蒸处理,间隔10 d后再分别进行第2次和第3次熏蒸处理,可以完全控制嗜卷书虱的发生。采用PH3 (12 μg/L)和气调(体积比例为35% CO2,1% O2,64% N2)交替处理能够延缓嗜卷书虱种群抗性的发展,交替处理3~5次可以完全控制嗜卷书虱的发生。     

褐飞虱对甲胺磷的抗性遗传

室内抗性筛选表明，褐飞虱对甲胺磷抗性的发展呈不规则的“S”形，第5代前抗性上升很慢，第5～15代间迅速上升，第15代后上升再次变慢。利用选育的抗甲胺磷褐飞虱品系和敏感品系，研究了褐飞虱对甲胺磷的抗性遗传形式。结果显示，正交和反交子代的显性度D值分别为0．5130和0．4673，表明抗性主效基因是不完全显性遗传的。利用剂量对数-死亡机率值曲线分析法，初步判断抗性遗传不是单基因控制的；卡方(χ^2)测验进一步证实，抗性遗传可能是两个或两个以上的基因控制。抗性筛选全过程和F5～F13的现实遗传力(h^2)分别为0．2190和0．2457，说明褐飞虱对甲胺磷抗性产生的速率较快，出现高抗性的风险较大。     

不同书虱品系的磷化氢半数击倒时间与抗性相关性研究

参照FAO推荐方法测定了磷化氢对嗜卷书虱(Liposcelis bostrychophila(Badonnel))2个品系、嗜虫书虱(L.entomophila(Enderlein))3个品系和小眼书虱(L.paeta(Pearman))3个品系等共8个不同来源书虱的毒力和抗性系数Rf,测定了磷化氢浓度为2mg/mL条件下供试各书虱品系的半数击倒时间KT50,分析了其LC50值与KT50值的相关性。结果为:3种书虱的8个品系对磷化氢的抗性差异明显,高抗性的嗜虫书虱的磷化氢抗性比敏感的嗜卷书虱高1000倍以上,各品系书虱的KT50值与Rf值呈正相关,相应LC50值之对数与KT50值的对数呈直线相关。结果表明,磷化氢对书虱成虫的半数击倒时间KT50值可以用来判断书虱抗性大小,并可用于快速判断抗性以指导现场熏蒸。     

嗜卷书虱和嗜虫书虱酯酶性质的比较研究

对嗜卷书虱Liposcelis bostrychophila和嗜虫书虱L. entomophila羧酸酯酶及乙酰胆碱酯酶(AChE)的生物化学性质进行了初步研究。结果表明:嗜虫书虱的羧酸酯酶活性明显高于嗜卷书虱,嗜卷书虱和嗜虫书虱羧酸酯酶对底物α-NA的Km值分别为0.665 7、0.285 7 mmol/L,Vmax值分别为1.672 2和2.463 1 mmol·(mg·30 min)-1。嗜卷书虱和嗜虫书虱乙酰胆碱酯酶的活性差异不显著,嗜虫书虱略高于嗜卷书虱。通过聚丙烯酰胺凝胶电泳,检测出8条嗜卷书虱、7条嗜虫书虱酯酶同工酶谱带,嗜卷书虱的酶谱分布比嗜虫书虱广。     

磷化氢对3种储粮书虱致死浓度与时间的比较研究

比较测定了磷化氢对嗜卷书虱Liposcelis bostrychophila(Pearman)、嗜虫书虱L.entomophila(Enderlein)和小眼书虱L.paeta(Pearman)等3种储粮书虱的毒力,并研究了在室温条件下磷化氢浓度分别为100、200、300、400和500mL/m3的完全致死时间。结果表明:磷化氢对嗜卷书虱、小眼书虱和嗜虫书虱的LD50值(95%置信限)分别为0.0039(0.0038～0.0042)、0.0804(0.0750～0.0887)和0.0815(0.0815～0.0892)mg/L,嗜虫书虱对磷化氢的耐受力比嗜卷书虱高20多倍。在试验浓度下第7d可全部致死嗜卷书虱,100mL/m3的浓度完全致死小眼书虱和嗜虫书虱则需22d多;200mL/m3完全致死小眼书虱和嗜虫书虱的时间约为19d,300mL/m3浓度完全致死小眼书虱和嗜虫书虱的时间在13d和16d,400mL/m3及以上浓度完全致死小眼书虱在7d以内,完全致死嗜虫书虱仍需13d。500mL/m3的浓度完全致死嗜虫书虱仅缩短到10d。采用磷化氢熏蒸书虱在100～500mL/m3的浓度范围内,提高浓度可以使完全致死书虱的时间明显缩短。     

8种植物精油对嗜卷书虱的杀虫活性及香青兰精油的GC-MS成分分析

为筛选新型环保植物源仓储害虫杀虫剂，采用水蒸汽蒸馏法提取8种植物精油，滤纸药膜法、密闭空气熏蒸法测定精油对嗜卷书虱成虫的触杀、熏蒸活性，筛选出高活性植物，并用气相质谱-色谱联用仪（GC-MS）对高活性植物精油进行化学成分的分析和鉴定。结果表明：香青兰、窃衣、啤酒花精油对嗜卷书虱具有较强的触杀活性，LD₅₀分别为157.43、349.34和633.07µ；g/cm²；香青兰、蒌蒿和窃衣精油对嗜卷书虱具有较好的熏蒸活性，LC₅₀分别为0.20、0.70和1.66 mg/L。香青兰精油经GC-MS分析，检测并鉴定到23个化学成分，相对含量占总含量的84.22%，其主要成分为乙酸香叶酯（16.26%）、丁香酚（13.90%）、香叶醛（13.20%）、草蒿脑（7.89%）、丙烯酸-2-乙基己酯（8.55%）以及橙花醛（7.60%）。研究结果表明香青兰精油对嗜卷书虱的生物活性较好，值得进一步研究。     

几种杀虫剂对嗜虫书虱的触杀作用

采用滤纸药膜法比较了常用8种杀虫剂对嗜虫书虱Liposcelis entomophila的触杀作用,在药剂的推荐浓度下有机磷类杀虫剂对嗜虫书虱的急性触杀作用强于其它药剂。同时测定了杀螟硫磷、敌敌畏和溴氰菊酯(含增效醚)3种药剂对嗜虫书虱的触杀毒力,其24h内触杀作用的LC_(50)分别为9．3284、2．1440和7．5007μg/cm~2,但杀螟硫磷的LC_(95)为459．4949μg/cm~2,远高于敌敌畏的8．2453μg/cm~2和溴氰菊酯(含增效醚)的14．5274μg/cm~2。此外,48h内敌敌畏等有机磷杀虫剂对嗜虫书虱的毒杀速度较其它供试药剂快。     

头花杜鹃挥发油的化学成分分析及其对3种仓储害虫的毒杀作用

本研究旨在明确头花杜鹃挥发油的化学成分及其对烟草甲、赤拟谷盗和嗜卷书虱的毒杀作用。利用GC/MS分析了头花杜鹃叶挥发油的化学组分;通过触杀和驱避试验测试头花杜鹃叶挥发油的生物活性。结果表明:从头花杜鹃叶挥发油中鉴定出的成分共有30种,占总成分的100.00%,其主要成分为:α-蒎烯(25.32%)、β-蒎烯(19.90%)和6,8-吡啶并[3,4-d]嘧啶-4(3H)-酮酸盐(7.45%);头花杜鹃叶挥发油对烟草甲、赤拟谷盗和嗜卷书虱的LD_(50)分别为44.40、104.92μg/头和98.87μg/cm~2;在测试2 h和4 h后其对赤拟谷盗和嗜卷书虱的驱避效果与阳性对照除虫菊素产生的效果一致。上述结果表明,头花杜鹃叶挥发油对烟草甲、赤拟谷盗和嗜卷书虱均具有较好的毒杀作用,这可能与头花杜鹃叶挥发油中的主要成分α-蒎烯有关。     

四种杀虫剂对两种书虱谷胱甘肽-S-转移酶和超氧化物歧化酶的影响

谷胱甘肽-S-转移酶（GSTs）能够参与多种类型杀虫剂的解毒代谢，如有机磷类、氨基甲酸酯类、拟除虫菊酯类和有机氯类。其介导的抗性与一种或多种GSTs的过量表达有关。超氧化物歧化酶（SOD）的功能是清除超氧阴离子自由基而形成H2O2，H2O2能与O2^-形成毒性更强的HO^-。书虱是一类个体微小、行动活泼的重要储藏物害虫，书虱对化学药剂的抗性发展很快，目前已发展为储粮中的害虫优势种群，但有关书虱体内酶系的研究较少。     

高效储粮杀虫涂料的研究

运用微胶囊技术把氰戊菊酯与毒死蜱原药包裹在囊中，然后与涂料制成0．5％、1．0％、2，0％、5．0％杀虫涂料，经试验，2．0％～5．0％的微胶囊杀虫涂料对谷蠹Rhyzopertha dominica F．、玉米象Sitophilus zeamais Motschulsy、赤拟谷盗Tribolium castanoznensis L，杀灭率为100％，对书虱Atropus pulsatoria Linnaeus、螨Acarus类杀灭率在90％以上，1．0％的杀虫涂料对以上害虫杀灭率在90％以上，进口杀虫涂料对谷蠹、玉米象、赤拟谷盗杀灭率在85％以上，但对书虱、螨类无效。经成本核算，若采用3％新型杀虫涂料，成本仅为进口杀虫涂料的29．1～33．3％。     

Toxicological and biochemical characterizations of AChE in Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae)

The toxicological and biochemical characteristics of acetylcholinesterases (AChE) in the resistant and susceptible strains (SS) of Liposcelis bostrychophila were investigated. The two resistant strains were the dichlorvos-resistant strain (DDVP-R) and the phosphine-resistant strain (PH₃-R) with resistance ratios of 22.36 and 4.51, respectively. Compared to their susceptible counterpart, the AChE activity per insect and the specific activity of AChE in DDVP-R and PH₃-R were significantly higher. There were also significant kinetic differences between DDVP-R and PH₃-R. The apparent Michaelis-Menten constant (K_m) for acetylthiocholine iodide (ATChI) was obviously lower in SS than that in PH₃-R, indicating a higher affinity to the substrate ATChI in the susceptible strains. The affinity for the substrate ATChI in DDVP-R and SS were not significantly different. The V_max value of the PH₃-R was significantly greater when compared to the V_max for the SS suggesting a possible over expression of AChE in this resistant strain. The inhibition of AChE to insecticide exposure in vitro revealed that all six insecticides were inhibitory for the extracted AChE’s. Based on the I₅₀ values, AChE of the SS were more sensitive to dichlorvos, paraoxon-ethyl, malaoxon and demeton-S-methyl than those of the two resistant strains. As for carbaryl and eserine, the PH₃-R suggested a significantly higher I₅₀s compared to the susceptible strain, while, no significant differences were found between SS and DDVP-R.     

Purification and biochemical characterization of glutathione S-transferases from three strains of Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae): Implication of insecticide resistance

Glutathione S-transferases (GSTs) catalyzing the conjugation of reduced glutathione (GSH) to a vast range of xenobiotics including insecticides were investigated in the psocid Liposcelis bostrychophila Badonnel. GSTs from susceptible and two resistant strains (DDVP-R for dichlorvos-resistant strain and PH₃-R for phosphine-resistant strain) of L. bostrychophila were purified by glutathione-agarose affinity chromatography and characterized by their Michaelis-Menten kinetics towards artificial substrates, i.e., 1-chloro-2,4-dinitrobenzene (CDNB), in a photometric microplate assay. The specific activities of GSTs purified from two resistant strains were significantly higher than their susceptible counterpart. For the resistant strains, GSTs both showed a significantly higher affinity to the substrate GSH while a declined affinity to CDNB than those of susceptible strain. The inhibitory potential of ethacrynic acid was very effective with highest I₅₀ value (the concentration required to inhibit 50% of GSTs activity) of 1.21 μM recorded in DDVP-R. Carbosulfan also exhibited excellent inhibitory effects on purified GSTs. The N-terminus of the purified enzyme was sequenced by Edman degradation, and the alignment of first 13 amino acids of the N-terminal sequence with other insect GSTs suggested the purified protein was similar to those of Sigma class GSTs.     

棉蚜对吡虫啉等杀虫剂抗药性品系的室内选育及抗药性风险评价

通过室内杀虫剂处理水培棉苗选育抗性棉蚜,研究棉蚜在药剂诱导下抗性的变化,比较吡虫啉、吡虫啉 增效磷、氧乐果和氰戊菊酯对棉蚜抗性诱导的差异,评价棉蚜对吡虫啉抗药性的风险.结果表明,用吡虫啉等药剂分别选育棉蚜至18代都能够诱导抗性上升,棉蚜对吡虫啉抗性达到10.08倍,对吡虫啉 增效磷的抗性达9.70倍;而用氧乐果和氰戊菊酯分别选育棉蚜至12代时,其抗性分别达28.48倍和35158倍.各抗性品系停止选育12代,抗性下降.     

杀虫剂室内选育亚洲玉米螟抗药性及交互抗性的研究

用4种杀虫剂及1种混合剂以点滴法分别逐代处理敏感性亚洲玉米螟五龄幼虫,以选育其抗药性。至30代,该虫对速灭杀丁及呋喃丹产生_的抗性分别达40.3及30.2倍,而后经5—6代正常饲养,其抗性虽有所衰退,但仍明显,可认为已成为抗性品系;而用甲基对硫磷、甲基对硫磷+速灭杀丁混合剂及辛硫磷(24代)处理,其抗性仅分别达1.8、3.4及4.0倍,由于获得抗性不明显,将此三种试虫称之选育品系。抗性品系对多种药剂存在着明显的交互抗性;而选育品系对其选育剂的抗性虽不明显,但它却对另外的有些药剂产生了抗性。     

斜纹夜蛾对茚虫威的抗药性汰选及交互抗性测定

为评估茚虫威抗性风险,在室内进行了斜纹夜蛾对茚虫威的抗性选育和交互抗性测定。经过10代6次室内抗性选育,获得了斜纹夜蛾对茚虫威抗性种群,与选育前相比,斜纹夜蛾对茚虫威的敏感性降低了15.63倍。抗性风险评估结果表明,斜纹夜蛾具有对茚虫威产生高水平抗性的风险。交互抗性测定发现,辛硫磷、高效氯氰菊酯和氟虫腈对茚虫威抗性种群的LC50值分别是同源对照种群的1.53、2.42和1.53倍,溴虫腈和灭多威对茚虫威抗性种群的LC50值分别是同源对照种群的0.78和0.96倍,表明茚虫威抗性种群对这几种杀虫剂未产生交互抗性。     

German cockroach resistance: Propoxur selection induces the same resistance spectrum as diazinon selection

A resistant laboratory strain of the German cockroach, Blattella germanica, was developed from a normal laboratory strain by selection with propoxur. Resistance to all insecticides except chlordane began increasing after 15 generations of selection and reached a plateau for most insecticides by generation 27. The resistant colony, designated B-strain, developed significant resistance to carbamates, organophosphorus compounds, pyrethrins and DDT, developed low resistance to gamma-BHC and no resistance to chlordane. The resistance spectrum, effect of synergists and inheritance of resistance of this propoxur resistant strain are similar to a diazinon resistant strain. Therefore, diazinon and propoxur may select for the same resistance mechanism(s) in this species. The practical implications of this research are discussed.     

草地贪夜蛾对甲氨基阿维菌素苯甲酸盐和虱螨脲的抗性风险评估

甲氨基阿维菌素苯甲酸盐(甲维盐)和虱螨脲是目前生产上防治草地贪夜蛾的主要杀虫剂,为评估其抗性风险,以福建省草地贪夜蛾田间种群为研究对象,在实验室抗性汰选品系选育基础上,采用数量遗传学域性状分析法并结合交互抗性测定,进行草地贪夜蛾对上述两种杀虫剂的抗性风险评估。结果表明：非连续汰选11代和10代后,草地贪夜蛾对甲维盐(F₁₁)和虱螨脲(F₁₀)的抗性倍数分别达30.57倍和11.35倍;抗性现实遗传力分别为0.403和0.555,且前半段筛选的抗性遗传力都远大于后半段;药剂在室内对草地贪夜蛾致死率为50%～90%时,对甲维盐和虱螨脲抗性倍数上升10倍需要汰选8～15代和6～12代。交互抗性测定显示,甲维盐汰选品系对氯虫苯甲酰胺、虱螨脲、虫螨腈无交互抗性,对茚虫威和乙基多杀菌素存在一定交互抗性。虱螨脲汰选品系对氯虫苯甲酰胺、甲维盐、茚虫威、虫螨腈和乙基多杀菌素均无交互抗性。结果表明：草地贪夜蛾对甲维盐和虱螨脲存在快速产生抗性的风险,但可通过与无交互抗性药剂轮用来延缓抗性发展。     

Inhibition of egg development by phosphine in the cosmopolitan pest of stored products Liposcelis bostrychophila (Psocoptera: Liposcelididae)

Phosphine-induced delay in development of eggs was investigated as a mechanism of resistance to this fumigant in Liposcelis bostrychophila Badonnel. One-day-old eggs of a susceptible and a strongly resistant strain of L bostrychophila were exposed to a range of phosphine concentrations for 6days at 30 (+/- 1) degrees C and 70 (+/- 2)% RH. Delay in mean hatching period occurred in both susceptible and resistant eggs, although it was more pronounced in the latter. A maximum delay of 2.65 days was recorded for eggs of the susceptible strain at 0.01 mg litre(-1) (the highest concentration at which eggs survived) and 13.39 days for the resistant strain at 1 mg litre(-1) (the highest concentration tested). Delay in egg development time was positively correlated with increasing phosphine concentration. Our results reveal that the most successful strategy to control resistant L bostrychophila is to apply relatively low concentrations of phosphine for extended exposure times (eg 0.05 mg litre(-1) for 16 days) that allow all eggs to hatch to the much less tolerant nymph stage.     

土耳其斯坦叶螨对杀螨剂的抗性选育及解毒酶活力变化

为探索土耳其斯坦叶螨的抗药性及其生化机理,在室内对敏感系土耳其斯坦叶螨分别用螺螨酯、甲氰菊酯和阿维菌素逐代处理,选育出抗性种群。结果表明,选育至15代,土耳其斯坦叶螨对螺螨酯、甲氰菊酯和阿维菌素的抗性指数分别达到268.63、37.98和112.68倍。分别测定敏感品系(SS)、抗螺螨酯(RS)、抗甲氰菊酯(RF)、抗阿维菌素(RA)品系的解毒酶活性显示,3种不同抗性品系相对SS品系的羧酸酯酶(CarE)、谷胱甘肽S-转移酶(GSTs)和多功能氧化酶(MFO)的比活力均有不同程度的提高,差异均达到显著水平(P0.05)。其中,RF品系的MFO比活力上升最快,是SS品系的12.7倍;RA品系的MFO比活力次之,是SS品系的5.76倍;RS品系的3种解毒酶比活力均增长较慢,其中CarE比活力上升最慢,是SS品系的1.31倍。由此表明,CarE、GSTs、MFO的活性增大可促进土耳其斯坦叶螨对3种杀虫剂的抗性形成;螺螨酯的抗性增强可能与CarE关系甚微;MFO活性的增加可能与甲氰菊酯抗性升高密切相关;GSTs、MFO的活性升高可能是土耳其斯坦叶螨对阿维菌素产生抗性的主要原因。