25%苯醚甲环唑微乳剂配方研究

本文研究了25%苯醚甲环唑微乳剂的配方,探讨了溶剂、助溶剂、乳化剂和水质等因素对产品物理稳定性的影响,进行了相应指标检测,取得了该产品的最优配方。     

甲维盐对斜纹夜蛾幼虫肠道细菌的影响

【目的】斜纹夜蛾幼虫属杂食性、高食量的害虫,通过分子生物学手段对经甲维盐处理后的斜纹夜蛾幼虫肠道微生物进行比对,研究肠道共生菌群受毒剂刺激后的代谢变化,探讨菌株的自身代谢与甲维盐的作用受体的相关性。【方法】基于Illumina MiSeq技术测序平台,对取食甲维盐和未取食甲维盐的斜纹夜蛾幼虫中肠细菌的16S rRNA可变区进行高通量测序,分析对比细菌群落结构多样性。【结果】肠杆菌属、根瘤菌属在斜纹夜蛾的肠道中占优势地位,经过甲维盐处理后两者的丰度大幅下降。沙雷氏菌属和黄单胞杆菌属在处理后减少到几乎为零,相反,原先不占据优势的棒状杆菌属和甲醇杆菌属,处理后丰度明显上升。【结论】甲维盐处理后的优势菌群以及丰富度均发生变化,表明斜纹夜蛾的肠道菌群结构可能与甲维盐毒理机制有关。     

氯虫苯甲酰胺和甲维盐对草地贪夜蛾幼虫的毒力及解毒酶活性的影响

为了研究氯虫苯甲酰胺和甲氨基阿维菌素苯甲酸盐(甲维盐)对草地贪夜蛾Spodoptera frugiperda的毒杀作用及解毒机制,采用叶片浸渍法测定了2种杀虫剂对草地贪夜蛾3龄幼虫的LC_(10)、LC_(20)与LC_(50),并研究这2种农药的亚致死剂量(LC_(20))对幼虫的羧酸酯酶(CarE)、谷胱甘肽-S-转移酶(GST)、细胞色素P450(CYP450)3种主要解毒酶活性的影响。结果表明甲维盐对3龄幼虫的毒力更高,48 h时LC_(10)、LC_(20)、LC_(50)分别为0.005、0.007、0.013 mg/L。2种农药处理72 h内,幼虫的3种酶活力呈现不同的动态变化。氯虫苯甲酰胺对CarE活力表现先诱导后抑制的作用,在24 h时CarE活力最大(36.75 U/mg);甲维盐对CarE活力表现先抑制后诱导的作用,在72 h时CarE活力最大(42.44 U/mg)。2种农药对GST活性在72 h内的变化一致,均呈现"诱导-抑制-诱导"的规律。氯虫苯甲酰胺处理后CYP450活性与对照相比无显著差异;甲维盐处理36 h、48 h、72 h幼虫体内CYP450活性均显著低于对照。     

西花蓟马对吡虫啉、辛硫磷和甲维盐的抗性风险和抗性稳定性

为有效控制西花蓟马的危害,采用吡虫啉、辛硫磷和甲维盐药液浸泡芸豆法,分别对西花蓟马敏感种群成虫进行抗性选育,获得抗性种群,应用抗性现实遗传力分析抗性遗传和抗性风险.结果表明:经过32代、32代和24代抗性选育,西花蓟马对吡虫啉、辛硫磷和甲维盐的抗性分别达到13.8、29.4和39.0倍.西花蓟马对吡虫啉、辛硫磷和甲维盐的现实抗性遗传力分别为0.112、0.166和0.259,西花蓟马对甲维盐的抗性上升速度最快,辛硫磷次之,吡虫啉最低.经过药剂筛选后,西花蓟马若虫与成虫对杀虫剂的敏感性差异较敏感种群显著缩小.停止用药剂筛选后继续饲养12代,西花蓟马对吡虫啉、辛硫磷和甲维盐的抗性水平都有一定程度下降,但都没有恢复到敏感性水平.西花蓟马对吡虫啉、辛硫磷和甲维盐具有较高水平抗性的风险,其中对吡虫啉的抗性发展速度相对较慢,且下降速度较快,因此选用吡虫啉防治西花蓟马更合适.     

甲维盐·毒死蜱及其复配对小菜蛾的毒力分析

以小菜蛾（Plutella xylostellar） 3龄幼虫为试虫测定了甲胺基阿维菌素苯甲酸盐、毒死蜱及两者5种不同配比的复配剂的毒力,测定结果建立了“时间-剂量-死亡率”模型.根据模型分析结果,甲胺基阿维菌素苯甲酸盐与毒死蜱混配后增效显著.在5种配比中以甲氨基阿维菌素苯甲酸盐∶毒死蜱 =1∶ 74为最佳配比,其24-60 h 4个时段的共毒系数在334到550之间;与单剂相比,该配比明显提高了24 h时段内和48-60 h时段的杀虫率.     

8%高效氯氟氰菊酯微乳剂对环境生物的安全性评价

高效氯氟氰菊酯是一种拟除虫菊酯类杀虫剂,对鳞翅目、鞘翅目和半翅目等多种害虫以及螨类都有一定的防治效果。关于拟除虫菊酯类杀虫剂对某种环境生物的单一安全性评价的研究颇多,但缺乏系统的评价。根据《化学农药环境安全评价试验准则》,测定了8％高效氯氟氰菊酯微乳剂对6种非靶标环境生物鹌鹑、蜜蜂、家蚕、斑马鱼、大型溞和蚯蚓的毒性,并进行了环境安全性评价。8％高效氯氟氰菊酯微乳剂对鹌鹑的经口毒性7 d LD50为54．4762 mg· kg-1,属中毒;对蜜蜂经口毒性的48 h LC50为2．7391 mg· L-1,属高毒;对家蚕和斑马鱼的96 h LC50分别为0．0067和0．0007 mg· L-1,均为剧毒;对大型溞的抑制毒性EC50（48 h）为1．2716 mg· L-1,属中毒;对蚯蚓的14 d LC50为32．3313 mg· kg-1,属低毒。本文明确了高效氯氟氰菊酯微乳剂对环境生物的毒性及安全性,可为其在农业生产中的合理利用及其对环境生物危害的风险控制提供依据。     

2.5%高效氟氯氰菊酯微乳剂对苹果桃小食心虫的田间应用技术研究

田间应用及安全性评价结果表明,2.5%高效氟氯氰菊酯微乳剂稀释2000～4000倍防治苹果树桃小食心虫Carposina niponensis Walsingham,药后5d各地防效分别为78.14%～99.57%、87.50%～96.58%、80.73%～96.20%,药后10d各地防效分别为84.49%～98.60%、77.78%～94.44%、80.66%～99.29%,药后15d各地防效分别为83.35%～100%、77.55%～98.90%、88.89%～96.58%。2.5%高效氟氯氰菊酯微乳剂稀释2000～3000倍处理与对照药剂2.5%高效氟氯氰菊酯乳油3000倍处理防效相当。最佳用药量以2000～3000倍为宜,施药适期为苹果果实膨大期,且桃小食心虫卵孵化盛末期,虫果率达1%时,用药后5～10d可有效控制虫害,持效期较长。药后苹果树未见异常。     

3.2%高效氯氰菊酯·甲氨基阿维菌素苯甲酸盐微乳剂对十字花科蔬菜主要害虫的控制作用

田间药效试验结果表明,3.2%高效氯氰菊酯·甲氨基阿维菌素苯甲酸盐微乳剂对十字花科蔬菜主要害虫甜菜夜蛾Spodoptera exigua(Hbner)、小菜蛾Plutella xylostella(L.)、菜青虫Pieris rapae(L.)和斜纹夜蛾Spodoptera litura(Fabricius)均具有优良的防治效果,并有较好的速效性和持效性。3.2%高效氯氰菊酯.甲氨基阿维菌素苯甲酸盐微乳剂20,25和30g/667m23个处理药后1d对甜菜夜蛾、小菜蛾、菜青虫和斜纹夜蛾的防治效果为60.67%～77.41%,药后3d的防治效果达81.82%～97.77%,药后7d的防治效果达83.74%～99.25%。3.2%高效氯氰菊酯.甲氨基阿维菌素苯甲酸盐微乳剂可以作为防治蔬菜主要害虫的有效药剂推广使用,推荐使用剂量为25～30g/667m2(12～14.4gai/hm2)。     

不同助剂对甲维盐微乳剂在水稻叶片上附着性能的影响

选用合适的助剂有利于提高农药在水稻叶片上的持留量,解决现有杀虫剂利用率偏低的问题。本文以水稻为试材,测定2.3%甲维盐微乳剂分别与4种农药助剂混用后,其药液表面张力、铺展面积、叶片最大持留量的理化性能差异。结果表明4种助剂均能降低药液表面张力,提高叶片持留量,提高铺展面积。当助剂浓度达到150 mg/L后,铺展面积不再增加;200 mg/L后,药液表面张力达到最低;300 mg/L后,叶面持留量达到最大。其中乳化剂1#表现最优,其次是乳化剂2#,然后是JFC,OP-10。因此,在稻田喷雾中,可利用增加助剂含量来达到降低用药成本和减少环境污染的目的。     

农药助剂对无人机施用甲维盐微乳剂的雾滴特性及蓟马防效的影响

我国在使用农药防控农作物病虫害上,无人机施药技术仍处于初级阶段,农药有效利用率低,飘失严重,防治效果较差。本研究通过添加助剂来增加药液到达靶标作物上的雾滴密度和药液沉积量,提高利用2.3%甲氨基阿维菌素苯甲酸盐微乳剂进行无人机喷雾对蓟马的防效。研究结果表明,添加助剂后,药液冠表层雾滴密度从84.3个/cm~2增加到了130.8个/cm~2,沉积量从0.4μL/cm~2提高到1.7μL/cm~2;内冠层雾滴密度从52.5个/cm~2增加到99.1个/cm~2,沉积量从0.1μL/cm~2提高到0.8μL/cm~2;药后5 d对蓟马的校正防效由31.18%提高到91.67%,试验结果表明,合理地添加助剂有利于提高无人机喷雾雾滴密度和沉积量,显著提高了农药对蓟马的防效。     

甲氨基阿维菌素苯甲酸盐微乳剂热贮稳定性研究

采用高效液相色谱法分析甲维盐微乳剂,以甲醇＋0．2％三乙胺溶液＋乙腈（V：V：V=30：30：40）为流动相,采用XterraRP184．6150mm色谱柱,检测波长245nm,测得54±2℃条件下14d分解率为3．42％。室内毒力测定热贮前后1％甲维盐微乳剂Lc50分别为0．499mg／L和0．524mg／L,热贮分解率为4．78％,与高效液相色谱测定结果基本一致。     

5%甲氨基阿维菌素苯甲酸盐微乳剂对6种环境生物的急性毒性

甲氨基阿维菌素苯甲酸盐是一种新型的抗生素类杀虫剂、杀螨剂,其大量使用可能会导致一系列的生态风险,因此有必要开展其对相关环境生物毒性的研究。测定了甲氨基阿维菌素苯甲酸盐对意大利蜜蜂、日本鹌鹑、斑马鱼、家蚕、大型溞和赤子爱胜蚓6种非靶标生物的急性毒性。5％甲氨基阿维菌素苯甲酸盐微乳剂对蜜蜂的急性经口LC50（48 h）为0．555 a．i．mg· L-1,对鹌鹑的经口LD50（7 d）为148．369 a．i．mg· kg-1,对斑马鱼的LC50（96 h）为0．368 a．i．mg· L-1,对家蚕的急性摄入毒性LC50（96 h）为0．005 a．i．mg· L-1,对大型溞的运动抑制毒性EC50（48 h）为0．020 a．i． mg· L-1,对蚯蚓的急性毒性LC50（14 d）为18．397 a．i．mg· kg-1。该农药对家蚕和大型溞均为剧毒,对蜜蜂和斑马鱼均为高毒,对鹌鹑中毒,对蚯蚓低毒。总体而言,甲氨基阿维菌素苯甲酸盐微乳剂对环境生物危害大,在使用过程中要注意。     

甲氨基阿维菌素苯甲酸盐微乳剂热贮稳定性研究

采用高效液相色谱法分析甲维盐微乳剂,以甲醇+0.2%三乙胺溶液+乙腈(V:V:V=30:30:40)为流动相,采用Xterra RP18 4.6150mm色谱柱,检测波长245nm,测得54±2℃条件下14d分解率为3.42%.室内毒力测定热贮前后1%甲维盐微乳剂LC50分别为0.499 mg/L和0.524 mg/L,热贮分解率为4.78%.与高效液相色谱测定结果基本一致.     

Assessing the resistance risk to emamectin benzoate in Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae): selection,cross-resistance dynamics and estimates of realized heritability

Emamectin benzoate, a non-systemic, translaminar, and broad spectrum insecticide, is excessively used in cotton. It kills the pest by suppressing the muscle contraction. Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is one of the major sap sucking pests of cotton in many countries and has been shown resistance to various insecticides. In this study, we have continuously selected P. solenopsis with emamectin benzoate in the laboratory from G₃ to G₁₈ to determine the resistance development and resistance risk to emamectin benzoate and also to evaluate the dynamics of cross-resistance (CR) development with three other insecticides. After continuing selection of P. solenopsis for 16 generations with emamectin benzoate, the emamectin selected strain (Ema-SEL) developed a 280.15-fold resistance when tested at G₁₉. Ema-SEL strain showed no CR to abamectin (0.28–1.65-fold), and profenofos (0.12–0.29-fold), but a very low to low CR to cypermethrin (6.02–11.29-fold). Abamectin was negatively cross-resistant with emamectin benzoate in Ema-SEL strain at G₁₃, G₁₅ and G₁₉ while profenofos also exhibited similar results at G₁₃, G₁₅, G₁₇ and G₁₉. Realized heritability (h²) of resistance to emamectin benzoate was 0.24 from G₃ to G₁₉. The results of projected rate of resistance development showed that if h² = 0.24, 0.34, and 0.44 at slope = 1.08, then 2.03, 1.43, and 1.11 generations, respectively are required for tenfold increase in LC₅₀ at 95 % selection intensity. Results of the present study suggested that P. solenopsis has the ability to develop resistance to emamectin benzoate but it can be managed by the alternate use of other insecticides including abamectin, profenofos and cypermethrin due to lack of/or very low to low CR with these insecticides.     

Effect of emamectin benzoate under semi-field and field conditions on key predatory biological control agents used in vegetable greenhouses

Predatory arthropods are commonly used as biological control agents (BCAs). They are released in commercial vegetable greenhouses as primary elements of integrated pest management programmes for some of the most devastating pests on pepper and tomato in southeastern Spain. Emamectin benzoate, a macro-cyclic lactone insecticide derived from the avermectin family of natural products, is being developed for the control of Lepidoptera pests on a variety of crops in Europe including vegetables. The compatibility of emamectin benzoate with the predatory BCAs Amblyseius swirskii Athias-Henriot and Orius laevigatus (Fieber) in field trials (direct spray and aged residues) and Macrolophus pygmaeus (Rambur) and Chrysoperla carnea (Stephens) in semi-field studies was studied. Emamectin benzoate at the highest recommended concentration (14.25 mg L^?1) was compatible with A. swirskii and O. laevigatus when applied 3 days before the introduction of the arthropods, but it was toxic when directly sprayed. M. pygmaeus and C. carnea adults survived to direct spray applications.     

Optimization and field use of a bioassay to monitor sea lice Lepeophtheirus salmonis sensitivity to emamectin benzoate

A bioassay for sea lice Lepeophtheirus salmonis sensitivity towards emamectin benzoate (EMB) was validated for field use. A probit regression model with natural responsiveness was used for the number of affected (moribund or dead) sea lice in bioassays involving different concentrations of EMB. Bioassay optimization included an evaluation of the inter-rater reliability of sea lice responsiveness to EMB and an evaluation of gender-related differences in susceptibility. Adoption of a set of bioassay response criteria improved the concordance (evaluated using the concordance correlation coefficient) between raters' assessments and the model estimation of EC50 values (the 'effective concentration' leading to a response of 50% of the lice not prone to natural response). An evaluation of gender-related differences in EMB susceptibility indicated that preadult stage female sea lice exhibited a significantly larger sensitivity towards EMB in 12 of 19 bioassays compared to preadult males. In order to evaluate sea lice sensitivity to EMB in eastern Canada, the intensive salmon farming area in the Bay of Fundy in southwestern New Brunswick was divided into 4 distinct regions based on industry health management practices and hydrographics. A total of 38 bioassays were completed from 2002 to 2005 using populations of preadult stage sea lice collected from Atlantic salmon Salmo salar farms within the 4 described regions. There was no significant overall effect of region or year on EC50 values; however, analysis of variance indicated a significant effect of time of year on EC50 values in 2002 and a potential effect in 2004 to 2005. Although the range of EC50 values obtained in this 3 yr study did not appear sufficient to affect current clinical success in the control of sea lice, the results suggest a seasonal- or temperature-associated variation in sensitivity to EMB. This will need to be considered if changes in EMB efficacy occur in the future.     

虫酰肼和甲维盐对甜玉米草地贪夜蛾的生物活性及田间防效

为了研究虫酰肼和甲氨基阿维菌素苯甲酸盐(甲维盐)对新入侵我国的草地贪夜蛾毒杀活性并为田间应用提供依据,采用浸叶法进行了室内毒力测定,采用喷雾法进行盆栽试验和田间小区试验。毒力测定表明虫酰肼对草地贪夜蛾2龄、3龄幼虫48 h LC_(50)分别为0.30 mg/L和0.26 mg/L,甲维盐对草地贪夜蛾2龄、3龄幼虫48 h LC_(50)分别为0.005 mg/L和0.002 mg/L,其LC_(50)活性是虫酰肼的60～128倍。盆栽试验表明,20%虫酰肼SC在20 mg/L、5%甲维盐ME 1mg/L喷雾处理后7 d后防效均为100%,在甜玉米田间小区试验最高防效均可达到90%以上。本研究结果表明,虫酰肼可推荐用于草地贪夜蛾的防治并可与甲维盐轮换使用或复配使用。     

苯甲酸钠对植物萌发的影响初探

苯甲酸钠是常用的食品防腐剂，对酵母菌和细菌的繁殖有较强的抑制作用。本文报告苯甲酸钠对大蒜和豌豆这两种植物萌发影响的初步试验，表明一定浓度的苯甲酸钠对植物的萌发有明显的抑制作用。     

Molecular cloning and characterisation of a novel P-glycoprotein in the salmon louse Lepeophtheirus salmonis

The salmon louse, Lepeophtheirus salmonis, is a crustacean ectoparasite of salmonid fish. At present, sea louse control on salmon farms relies heavily upon chemical treatments. Drug efflux transport, mediated by ABC transporters such as P-glycoprotein (Pgp), represents a major mechanism for drug resistance in parasites. We report here the molecular cloning of a new Pgp from the salmon louse, called SL-PGY1. A partial Pgp sequence was obtained by searching sea louse ESTs, and extended by rapid amplification of cDNA ends (RACE). The open reading frame of SL-PGY1 encodes a protein of 1438 amino acids that possesses typical structural traits of P-glycoproteins, and shows a high degree of sequence homology to invertebrate and vertebrate P-glycoproteins. In the absence of drug exposure, SL-PGY1 mRNA expression levels did not differ between a drug-susceptible strain of L. salmonis and a strain showing a ~7-fold decrease in sensitivity against emamectin benzoate, the active component of the in-feed sea louse treatment SLICE (Merck Animal Health). Aqueous exposure of the hyposensitive salmon louse strain to emamectin benzoate (24h, 410 μg/L) provoked a 2.9-fold upregulation of SL-PGY1. Adult male lice of both strains showed a greater abundance of SL-PGY1 mRNA than adult females.