八种杀虫剂对夹竹桃蚜的毒力及防治效果分析

测定了8种杀虫剂对夹竹桃蚜的毒力及防治效果,结果表明杀虫效果以啶虫脒最好,其24 h的LC50值为0.79 mg/L;其他7种杀虫剂对夹竹桃蚜的毒力大小依次为氟啶虫酰胺、氟啶虫胺腈、螺虫乙酯、吡虫啉、噻虫啉、烯啶虫胺和呋虫胺,啶虫脒对夹竹桃蚜的毒力是呋虫胺的8.1倍。在各试验浓度下,螺虫乙酯的1 d田间防效最差,速效性不理想,氟啶虫胺腈的1 d防效最好;而螺虫乙酯、氟啶虫胺腈、氟啶虫酰胺、呋虫胺、噻虫啉与烯啶虫胺的14 d防效均在99%以上,表明这些药剂对夹竹桃蚜的持效性理想,推荐生产中使用这些药剂防治夹竹桃蚜。     

杀虫剂和除草剂对生防菌盾壳霉生长的影响

本研究采用FAO推荐的菌落直径法测定了8种杀虫剂、4种除草剂、3种植物生长调节剂和1种农用抗菌素对盾壳霉菌丝的毒力。研究结果表明,杀虫剂中氯氰菊酯、阿维菌素、毒死蜱和敌敌畏对盾壳霉生长的抑制作用较大,但除敌敌畏外,其他杀虫剂EC50值均高于相应的田间最大推荐使用浓度(MRAR);辛硫磷和氧乐果对盾壳霉的抑制作用次之;而吡虫啉和灭多威则对其生长几乎没有抑制作用。4种除草剂的EC50值均明显低于相应的MRAR值,对盾壳霉生长有强的抑制作用。在正常使用浓度下植物生长调节剂萘乙酸、赤霉素、云大120对盾壳霉的生长几乎没有抑制作用。链霉素对其生长有一定影响,但EC50明显高于MRAR值。因此,在使用盾壳霉防治菌核病的田中,可以合理使用较安全的植物生长调节剂及吡虫啉和灭多威等杀虫剂,而应尽量减少和避免使用吡氟乙草灵、草甘膦、百草枯等除草剂。     

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。     

雷公藤非生物碱对小菜蛾的生物活性研究

试验研究雷公藤非生物碱对小菜蛾(Plutella xylostella)的生物活性结果表明,雷公藤非生物碱对小菜蛾具有较强的拒食、毒杀以及生长发育抑制作用。雷公藤非生物碱对2龄小菜蛾幼虫的选择性与非选择性拒食中浓度(AFC50)分别为34.89mg/L和42.33mg/L;毒杀中浓度(LC50)为49.86mg/L;100mg/L的雷公藤非生物碱对小菜蛾幼虫的生长发育抑制率达90%以上;但雷公藤非生物碱的杀卵作用不显著,以400mg/L雷公藤非生物碱处理小菜蛾卵后,其孵化率和孵化后幼虫存活率仍分别达53.48%和46%。     

新烟碱类和阿维菌素类药剂对蚯蚓的急性毒性效应

为评价农药对蚯蚓的生态风险提供基础数据,采用滤纸法和人工土壤法测定了新烟碱类和阿维菌素类药剂对蚯蚓的急性毒性效应。滤纸法测定结果表明,吡虫啉、啶虫脒、烯啶虫胺、氯噻啉和噻虫啉5种新烟碱类药剂对蚯蚓的LC50值范围为0.0089（0.0075～0.010）μg·cm^-2～0.44（0.34～0.56）μg·cm^-2（48h结果）,噻虫嗪对蚯蚓的LC50值在24h和48h均大于62.91μg·cm^-2;阿维菌素、依维菌素和甲氨基阿维菌素苯甲酸盐3种阿维菌素类药剂对蚯蚓的LC50值范围为4.52（3.71～5.50）μg·cm^-2～22.76（18.68～27.73）μg·cm^-2（48h结果）。人工土壤法测定结果表明,5种新烟碱类药剂（除噻虫嗪外）对蚯蚓的LC50值范围为1.54（1.43～1.71）mg·kg^-1～17.29（16.44～19.41）mg·kg^-1（14d结果）,噻虫嗪对蚯蚓的LC50值在第7d和14d均大于1200mg·kg^-1;3种阿维菌素类药剂对蚯蚓的LC50值范围为27.93（26.04～29.81）mg·kg^-1～175.33（162.82～188.91）mg·kg^-1（14d结果）。根据《化学农药环境安全评价试验准则》,吡虫啉、啶虫脒和烯啶虫胺对蚯蚓属于中毒级,其他的药剂对蚯蚓属于低毒级。     

3种新烟碱类杀虫剂对月季长管蚜的室内毒力测定实验初报

为明确新烟碱杀虫剂对月季长管蚜的的毒力效果,选用三代新烟碱杀虫剂吡虫啉、噻虫嗪以及氟啶虫胺腈,采用带叶浸虫法对月季长管蚜进行毒力测定。结果表明:3种杀虫剂对月季长管蚜虫都有较高的毒力,其中噻虫嗪毒力最高,LC_(50)为2.420 mg·L~(-1);吡虫啉、氟啶虫胺腈的LC_(50)分别为3.725 mg·L~(-1)和4.728 mg·L~(-1),说明3种新烟碱农药对月季长管蚜均有较好的防治效果。     

五种杀虫剂对卵寄生性天敌广赤眼蜂室内安全性评价

在实验室条件下分别用药膜法、寄主卵块喷雾法和盆栽法测定了苏云金杆菌等5种杀虫剂菜田防治推荐浓度对广赤眼蜂5种虫态的毒性及雌蜂的残留毒性.不同农药对广赤眼蜂各虫态的毒性存在差异, 对其存活、羽化和寄生能力等有不同程度的影响, 其中对成蜂的毒性最强.苏云金杆菌和啶虫脒对广赤眼蜂5种虫态的杀伤力较低, 对羽化蜂的寿命和翅的发育影响较小或无影响, 同时施药后的残效期较短, 对成蜂的存活和寄生能力的影响较小.阿维菌素除卵和幼虫期处理对广赤眼蜂无影响或影响轻微外, 预蛹和蛹期处理, 羽化率降低, 羽化后雌蜂寿命缩短, 前翅发育不全比例升高, 其不良影响随蜂的发育呈增大趋势; 此外, 喷药后7 d其残留农药对雌蜂的存活和寄生能力仍有较大影响.高效氯氟氰菊酯卵期至蛹期处理广赤眼蜂能显著降低该蜂的羽化率, 成蜂期处理的死亡率在70%以上, 但该药残留毒性期较短, 喷药后5 d成蜂存活和寄生能力基本恢复正常.毒死蜱对各虫期的广赤眼蜂均有极强的杀伤力, 喷药后10 d仍有很高的残留毒性.总之, 苏云金杆菌和啶虫脒对广赤眼蜂无毒或毒性较低, 是生防区理想的配合药剂;阿维菌素和高效氯氟氰菊酯毒性中等, 使用时要尽量避开赤眼蜂成蜂活动期;毒死蜱毒性极强, 生防区应禁止使用.     

五种杀虫剂对卵寄生性天敌广赤眼蜂室内安全性评价

在实验室条件下分别用药膜法、寄主卵块喷雾法和盆栽法测定了苏云金杆菌等5种杀虫剂菜田防治推荐浓度对广赤眼蜂5种虫态的毒性及雌蜂的残留毒性。不同农药对广赤眼蜂各虫态的毒性存在差异, 对其存活、羽化和寄生能力等有不同程度的影响, 其中对成蜂的毒性最强。苏云金杆菌和啶虫脒对广赤眼蜂5种虫态的杀伤力较低, 对羽化蜂的寿命和翅的发育影响较小或无影响, 同时施药后的残效期较短, 对成蜂的存活和寄生能力的影响较小。阿维菌素除卵和幼虫期处理对广赤眼蜂无影响或影响轻微外, 预蛹和蛹期处理, 羽化率降低, 羽化后雌蜂寿命缩短, 前翅发育不全比例升高, 其不良影响随蜂的发育呈增大趋势; 此外, 喷药后7 d其残留农药对雌蜂的存活和寄生能力仍有较大影响。高效氯氟氰菊酯卵期至蛹期处理广赤眼蜂能显著降低该蜂的羽化率, 成蜂期处理的死亡率在70%以上, 但该药残留毒性期较短, 喷药后5 d成蜂存活和寄生能力基本恢复正常。毒死蜱对各虫期的广赤眼蜂均有极强的杀伤力, 喷药后10 d仍有很高的残留毒性。总之, 苏云金杆菌和啶虫脒对广赤眼蜂无毒或毒性较低, 是生防区理想的配合药剂;阿维菌素和高效氯氟氰菊酯毒性中等, 使用时要尽量避开赤眼蜂成蜂活动期;毒死蜱毒性极强, 生防区应禁止使用。     

原生质体融合构建防病、杀虫和内生多功能工程菌

摘要：将含vip3A基因的苏云金芽孢杆菌（Bacillus thuringiensis）和具有内生及防病等优良特性的枯草芽孢杆菌(B. subtilis)进行原生质体融合，构建了1株多功能工程菌, 经PCR检测vip3A基因呈阳性，并测定了融合子对黄瓜枯萎病菌(Fusarium oxysporum f.sp.cucumerinum)的拮抗作用、对小菜蛾(Plutella xylostella)毒性及内生定殖能力。实验结果显示多功能工程菌对黄瓜枯萎病菌具有拮抗作用，对小菜蛾的校正杀虫效率在59%以上，并具有内生定殖能力。     

氟啶虫胺腈在棉花和土壤中的检测方法与残留动态研究

研究和建立了氟啶虫胺腈在土壤、棉籽和棉叶中的高效液相色谱检测方法,并在天津和杭州两地开展了氟啶虫胺腈在棉花中的田间残留试验研究。样品采用乙腈提取,正己烷萃取,氟罗里硅土柱层析净化,正己烷/丙酮(体积比6∶4)混合液洗脱,减压浓缩至干,甲醇定容,高效液相色谱配可变波长紫外检测器进行检测。当分别在空白土壤、棉籽和棉叶样品中添加浓度为0.05~2.5mg·kg-1的氟啶虫胺腈标准品时,其平均添加回收率在76.81%~94.43%之间,相对标准偏差(RSD)在0.54%~7.20%之间;氟啶虫胺腈的最小检出量为1 ng,在所有样品中的最低检出浓度均为0.05mg·kg-1。田间残留试验结果表明,氟啶虫胺腈在土壤和棉叶中的消解规律符合一级动力学模型Ct=C0e-kt,消解半衰期分别为1.36~5.10 d和6.13~9.37d。最终残留试验结果表明,在棉花田手动喷雾施用50%氟啶虫胺腈水分散粒剂,按推荐剂量和1.5倍推荐剂量施药,兑水喷雾处理2~3次,每次施药间隔7 d,在距最后1次施药7、14 d和21d时,氟啶虫胺腈在棉籽和土壤中的残留量均小于方法最低检出浓度0.05mg·kg-1。     

Highly sensitive enzyme-linked immunosorbent assay for chlorpyrifos. Application to olive oil analysis

Highly sensitive enzyme-linked immunoassays for chlorpyrifos, one of the most applied insecticides, are presented. Several haptens were synthesized for immunoreagent production and ELISA development. The best immunoassays obtained are based on an indirect coated-plate immunoassay format. Two assays were optimized; one shows a limit of detection of 0.3 ng L(-1), an I50 of 271 ng L(-1), and a dynamic range between 4 and 16 474 ng L(-1). The other one has a limit of detection of 0.07 ng L(-1), an I50 of 7 ng L(-1), and a dynamic range between 0.4 and 302 ng L(-1). The assays were used to quantify chlorpyrifos in olive oil using a simple and rapid sample extraction procedure. The good recoveries achieved in both assays (109% mean value) and the agreement with values given by the GC reference method (110% mean value) indicate their potential for either screening or laboratory quantification.     

家蝇乙酰胆碱酯酶的纯化、生化性质及其对杀虫剂敏感性的研究

采用CEA亲和层析法对家蝇AChE进行纯化,测定了不同温度、pH值、ATChI浓度、DTNB浓度对AChE活性的影响,并测定了不同杀虫剂对纯酶和粗酶的抑制作用。结果表明,CEA纯化倍数为672．36,产率为34．68％;当温度为35℃时,粗酶和纯酶的AChE活性最高;当pH=7．2时,纯化后AChE的活性最高,随后随着pH的升高AChE的活性反呈下降趋势;当pH=7．8时,粗酶AChE活性最高;当底物浓度的2500umol·L^-1时,纯化AChE活性达到最大值,当底物浓度为1500umol·L^-1时,粗酶活性达到最大值;粗酶和纯化的AChE活性的两个波峰出现在DTNB浓度为0．2mol·L^-1和0．4mol·L^-1时;仲丁威、乙酰甲胺磷、速灭威、甲胺磷、毒死蜱、克百威、抗蚜威、灭多威和辛硫磷等9种杀虫剂对粗酶和纯酶AChE的I岛比值都大于6,甲萘威对纯酶和粗酶AChE的lC50比值为4．826,二嗪磷的为1．184,三唑磷的为0．099。     

5种杀虫剂在水-人工底泥系统中对大型溞的急性毒性及其比较

建立了包含＂水＂和＂底泥＂两相的水蚤毒性测试系统（水相为全人工培养液,＂底泥＂为OECD配方标准化人工土）,并通过该系统测得毒死蜱（chlorpyrifos）、氟虫腈（fipronil）、氰戊菊酯（fenvalerate）、氟氯氰菊酯（cyfluthrin）、联苯菊酯（bifenthrin）对大型溞（Daphnia magna）的急性毒性（48 h-LC50）分别为9.01、88.1、0.142、0.097 6、0.050 4μg.L-1。对比水相的急性毒性测定结果发现,在有底泥的条件下,所测得的联苯菊酯、氟氯氰菊酯、毒死蜱的大型溞毒性低于水相的测定结果,而氰戊菊酯、氟虫腈的毒性则比水相中的测定结果要高。研究结果反映出药剂和受试生物在＂水-底泥＂系统内相互作用的复杂性和难以预见性,从而在为相关农药生态安全评价提供科学依据的同时,为在更接近实际暴露状态下开展评价试验提供了一种简便有效的方法。     

杀虫双对土壤脲酶活性特征的影响

通过模拟方法研究杀虫双对土壤脲酶活性特征参数的影响。结果表明 :不同生态区域土壤脲酶特征具有明显差异。杀虫双明显抑制脲酶活性 ,且随浓度增加 ,脲酶活性、酶促反应的Vmax、Vmax/Km、k减小 ,Km 增大 ,除 6号土样的Km 处理外均达到显著或极显著相关 ,揭示出脲酶特征参数可从不同角度表征杀虫双对土壤脲酶活性的影响 ,获得其作用机理为混合型抑制。脲酶活性ED50 值与土壤有机质、全氮和全磷呈现显著或极显著正相关关系 ,表明高有机质含量的土壤可明显减轻杀虫双的污染。     

Effects of foliar and soil insecticide applications on the collembolan community of an early set-aside arable field

Effects of foliar and soil insecticide applications on collembolan density and community structure were investigated in an early set-aside arable field. Insecticides were applied separately and in combination to the soil surface (chlorpyrifos) and vegetation (dimethoate). The treatments were established to investigate effects of above- and below-ground insects on plant succession. Starting in 1997, the insecticides were applied from April to November at 2-week (dimethoate) or monthly intervals (chlorpyrifos). Samples were taken in 2000 prior to and after insecticide application in March and June, respectively. Both insecticides are lethal to Collembola and insecticide applications resulted in a strong decline in the density of total Collembola. Application of chlorpyrifos reduced collembolan density to a greater extent than dimethoate; the effect of the combined application on total collembolan numbers was similar to that of chlorpyrifos only. Collembolan numbers recovered after the insecticide applications in 1999, but in the treated plots populations were still reduced in March 2000 before the re-application of insecticide treatments in that year. The insecticide applications changed the dominance structure of the collembolan community, but had no effects on species composition. The results may be of relevance for the interpretation of studies on plant–insect herbivore interactions using insecticides.     

Development of a compound-specific ELISA for flufenoxuron and an improved class-specific assay for benzoylphenylurea insect growth regulators.

This study describes immunochemical approaches for the compound-specific detection of flufenoxuron and class-specific detection of benzoylphenylurea (BPU) insecticides. With the aim of developing a highly specific immunoassay for flufenoxuron, a hapten was synthesized by introducing a spacer arm at the 2,6-difluoro substituent aromatic ring of a flufenoxuron derivative. An IC(50) value of 2.4 ppb was obtained for flufenoxuron, with detection of the other four BPUs being more than 4000-fold less sensitive. For the development of class-specific ELISA for five BPUs, a new approach was used for the hapten preparation in which a butanoic acid linkage was introduced into the 3,5-dichloro-substituted aniline ring of chlorfluazuron analogue. Although the resultant ELISA still exhibited slightly differing cross-reactions for these five BPUs, this method had broader specificity than the previously reported polyclonal antibody-based ELISA. Spike and recovery studies for five BPUs in soil and water indicated that both the compound- and class-specific ELISAs were able to quantitatively detect BPU residues in soil and water. This study also provided additional insights into the influence of the immunizing hapten structure on the specificities of the antibodies obtained.     

Simultaneous degradation of mixed insecticides by mixed fungal culture isolated from sewage sludge

The degradation of mixed (DDT and chlorpyrifos) insecticides by mixed insecticide enriched cultures was investigated. The mixed fungal population was isolated from mixed insecticide acclimatized sewage sludge over a period of 90 days. Gas chromatography was used to detect the concentration of mixed insecticides and calculate the degradation efficiency. The results showed that the degradation capability of the mixed microbial culture was higher in low concentrations than in high concentrations of the mixed insecticides. After 12 weeks of incubation, mixed pesticide enriched cultures were able to degrade 79.5-94.4% of DDT and 73.6-85.9% of chlorpyrifos in facultative cometabolic conditions. The fungal strains isolated from the mixed microbial consortium were identified as Fusarium sp. isolates GFSM-4 (ITCC 6841) and GFSM-5 (ITCC 6842). The fungal culture GFSM-4 could not utilize mixed insecticides as source of carbon and nitrogen, probably due to high combined toxicity of the mixed insecticides. Liquid media deficient in carbon (1% mannitol) and nitrogen (0.1% sodium nitrate) source increased the degradation efficiency of DDT and chlorpyrifos to 69 and 45%, respectively. The media with normal carbon and deficient nitrogen (0.1% sodium nitrate) sources extensively increased the degradation efficiencies of DDT (94%) and chlorpyrifos (69.2%). Traces of p,p'-dichlorobenzophenone and desdiethylchlorpyrifos were observed in the liquid medium, which did not accumulate probably due to further rapid degradation. This fungal isolate (GFSM-4) was able to degrade simultaneously DDT (26.94%) and chlorpyrifos (24.94%) in sterile contaminated (50 mg of each insecticide kg(-1)) soil in aerobic conditions.     

4种鱼类肝脏细胞色素P450对毒死蜱、对硫磷及马拉硫磷的脱硫代谢

以毒死蜱、对硫磷及马拉硫磷为供试农药,以斑马鱼、剑尾鱼、麦穗鱼及太阳鱼为供试生物,研究了3种农药对4种鱼的急性毒性,4种鱼肝细胞色素P450对3种农药的脱硫代谢作用及两者之间的相关性。结果表明,毒死蜱对于上述4种鱼的96hLC50分别为1.94、0.171、0.0273、0.0681mg·L^-1;对硫磷为2.6、0.0559、1.78、1.02mg·L^-1;马拉硫磷为7.07、0.907、6.03、0.172mg·L^-1。4种鱼肝脏P450对于毒死蜱代谢的Vmax/Km值分别为1.67×10^4、2×10^4、5×10^4、2×104min^-1;对于对硫磷代谢的Vmax/Km值分别为2×10^4、5×10^5、1.11×10^5、1.43×10^5min^-1;对于马拉硫磷的值分别为5×10^3、5×10^4、2.5×10^3、1.67×10^4min^-1。96hLC50值与Vmax/Km值大体呈负相关,其中毒死蜱的相关性较弱,对硫磷及马拉硫磷的相关性较强（R^2值分别为0.2181、0.8490、0.5102）。研究结果说明P450在鱼类耐药性形成过程中发挥了阻碍作用。     

Reduction of azinphos-methyl, chlorpyrifos, esfenvalerate, and methomyl residues in processed apples

McIntosh, Red Delicious, and Golden Delicious from two years of experimental spray programs using azinphos-methyl, chlorpyrifos, esfenvalerate, and methomyl were processed into frozen apple slices, applesauce, single-strength juice, and juice concentrate. Residue levels were expressed as micrograms per 150 g of apple or the equivalent amount of apple product to calculate the percentage change in these pesticides brought about by processing. Producing single-strength apple juice reduced azinphos-methyl, chlorpyrifos, esfenvalerate, and methomyl residues by 97.6, 100, 97.8, and 78.1%, respectively. Production of applesauce reduced all four compounds by >/=95%. Azinphos-methyl, chlorpyrifos, esfenvalerate, and methomyl residues were reduced in apple slices by 94.1, 85.7, 98.6, and 94.7%, respectively. Processing is shown to be very effective in reducing the levels of these pesticides.