The synergistic advantage of combining chloropicrin or dazomet with fosthiazate nematicide to control root-knot nematode in cucumber production

The highly-damaging root-knot nematode(Meloidogyne spp.,RKN)cannot be reliably controlled using only a nematicide such as fosthiazate because of increasing pest resistance.In laboratory and greenhouse trials,we showed that chloropicrin(CP)or dazomet(DZ)synergized the efficacy of fosthiazate against RKN.The combination significantly extended the degradation half-life of fosthiazate by an average of about 1.25 times.CP or DZ with fosthiazate reduced the time for fosthiazate to penetrate the RKN cuticle compared to fosthiazate alone.CP or DZ combined with low or medium rate of fosthiazate increased the total cucumber yield,compared to the use of each product alone.A low-dose fosthiazate with DZ improved total yield more than a low dose fosthiazate with CP.Extending the half-life of fosthiazate and reducing the time for fosthiazate or fumigant to penetrate the RKN cuticle were the two features that gave the fumigant-fosthiazate combination its synergistic advantage over these products used singularly.This synergy provides the opportunity for farmers to use a low dose of fosthiazate which lowers the risk of RKN resistance.Farmers could combine DZ at 30 g m^-2 with fosthiazate at a low rate of 0.375 g m^-2 to control RKN and adequately control two major soil-borne diseases in cucumber greenhouses.

Determination of Fosthiazate Residue in Ginger by Gas Chromatography

[Objectives] An analytical method was established for determining fosthiazate residue in ginger by gas chromatography with flame photometric detector(GC-NPD) to evaluate the safety of fosthiazate in ginger. [Methods] The fosthiazate residue in ginger was extracted with dichloromethane, and subjected to sodium chloride salt-out and liquid-liquid extraction with hexane and dichloromethane(the plant and soil samples had no need for the later two steps). The analysis was performed on gas chromatograph equipped with a flame photometric detector(GC-FPD), and the fosthiazate residue was quantitatively determined by calculating the peak area. [Results] The results of degradation dynamics showed that the half-life of fosthiazate was 7.2-8.7 d in ginger plants, and was 9.9-19.8 d in the soil. The results of the final residue test showed that after applying the fosthiazate granules according to the recommended high dose(active component 58.2 g a.i/m^2,WK) and low dose(38.8 g a.i/m^2,WK) once, the final residual amounts of fosthiazate in the ginger and soil were estimated to be <0.02 mg/kg and <0.02-0.103 mg/kg, respectively, while no fosthiazate residue was detected in all control samples(<0.02 mg/kg). The maximum residue limit(MRL) of fosthiazate in ginger was not established in China, and was 0.2 mg/kg in Japan. [Conclusions] The method was proved to meet the basic requirements of pesticide residue analysis on sensitivity, accuracy and precision and have good linearity. It is recommended that when using fosthiazate granules to control root-knot nematode and root rot in ginger, it is applied at the highest dose of 38.8 g ai/m^2,WK once 30 d before ginger cultivation to treat the soil, and ginger is harvested in the ginger harvest period.

Study on Sustained-Release Pesticides Blended with Fosthiazate-Stearic Acid/Expanded Perlite

The low utilization rate of pesticides makes the migration of pesticides in water and soil,which brings great harm to the ecosystem.The development of pesticide carriers with good drug loading capacity and release control abil-ity is an effective method to realize effective utilization of pesticides and reduce pesticide losses.In this work,fosthiazate-stearic acid/expanded perlite sustained-release particles were successfully prepared by vacuum impregnation using expanded perlite(EP)as carrier,fosthiazate(FOS)as model pesticide and stearic acid(SA)as hydrophobic matrix.The structure and morphology of the samples were studied by BET,FT-IR,TGA,XRD,DSC and SEM.The effects of different mass ratios of FOS to SA on loading capacity and release rate at 24 h were investigated.The sustained release behavior of FOS-SA/EP at different temperatures and pH values was investigated by static dialysis bag method.The results showed that FOS and SA were adsorbed in EP pores by physical interaction.With the mass ratios of FOS to SA decreasing from 7:3 to 3:7,the 24 h release rate of FOS-SA/EP decreased from 18.77%to 8.05%,and the drug loading decreased from 461.32 to 130.99 mg/g.FOS-SA/EP showed obvious temperature response at 25℃,30℃ and 35℃,the cumulative release rate(CRR)of 200 h were 33.38%,41.50%and 51.17%,respectively.When pH=5,the CRR of FOS was higher than that of pH=7,and the CRR of FOS for 200 h were 49.01%and 30.12%,respectively.At different temperatures and pH=5,the release mechanism of FOS-SA/EP belongs to the Fickian diffusion mechanism;When pH=7,the diffusion mechanism is dominant,and the dissolution mechanism is complementary.

Uptake and distribution of ¹⁴C-labeled Fosthiazate in tomato (<i>Lycopersicon esculentum</i>L.)

The uptake of 14C-labeled fosthiazate (0.75 mg.L–1) by tomato plants was studied in solution culture both in the presence or absence of 2, 4 dinitrophenol (DNP, 1 × 10–2 mM), a metabolic inhibitor. Fosthiazate was rapidly taken up by tomato plants and nearly one third of the finally absorbed quantity was taken up in the first half an hour. The translocation of fosthiazate to the shoot part was under metabolic control during the initial stage of uptake. The kinetics of uptake both in the presence and absence of DNP conformed well to the dual phase than a single phase. In the presence of DNP, the uptake capacity (Vmax1) for the initial phase suffered, approximately three fold reduction in comparison to the absence of DNP while Vmax2 for the latter phase was statistically similar to the value observed in the absence of DNP signifying the metabolic dependence of the initial uptake phase. Autoradiography indicated that fosthiazate in the tomato plants tends to accumulate in the roots and at the root-shoot junction. In shoot, it is accumulated in the older leaves especially, near the leaf tip and margins.

Study on the Toxicity Effect of Abamectin and Chlorpyrifos on Grass Carp(Ctenopharyngodon idllus)

[ Objective] The study aimed to discuss the toxicity effect of abamectin and ehlorpyrifos on grass carp （ Ctenopharyngdon idllus ） and their interrela- tions. [ Method] Taking healthy and active grass carp as the object, the acute toxicity test of single pesticide and the combined toxicity test of two pesticides on grass carp were carried out. [ Result] The LC50 of abamectin and chlorpyrifes and the mixture of two pesticides against grass carp at 24, 48, 72 and 96 h were as follows： abamectin： 0.54, 0.49, 0. 17 and 0.10 rag/L; chlorpyrifes ： 0.29, 0.21, 0.12 and 0.05 rag/L; the mixture of two pesticides ： 1.22, 1.08, 0.99 and 0. 86 mg/L. The safe concentration （SC） of ahamectin, chlorpyrifos and the mixture of two pesticides were 0.010, 0.005 and 0.086 rag/L, respectively. The tox- icity of the pesticides in sequence was ablorpyrifos 〉 ahamectin 〉 the mixture of two pesticides. [ Conclusion ] Different concentrations of abamectin, chlorpyrifos and the mixture of two pesticides had remarkable effect on the growth of grass carp, the higher the concentration was, the greater the toxicity effect was. Ahamectin at low toxicity intensity had certain relief function on the toxicity of ehlorpyrifos.

二斑叶螨对阿维菌素不同抗性水平与解毒酶的关系分析

二斑叶螨是世界危险性有害生物。阿维菌素是二斑叶螨防治中使用最为广泛的杀螨剂之一,其不合理施用导致的抗药性问题日益严重。探究二斑叶螨对阿维菌素的抗性机理,可为延长药剂的使用寿命及制定综合防控策略提供理论依据。为此,本研究首先开展了阿维菌素对二斑叶螨田间种群、实验室筛选的抗性种群、敏感种群的生物测定,发现3个种群的24 h致死中浓度(LC_(50))分别为7.19、2061.43、0.10μg/mL, 48 h的LC_(50)分别为6.32、1971.55、0.09μg/mL。以敏感种群的LC_(50)为基准,田间种群和实验室抗性种群的抗性倍数超过70倍和20000倍,分别属于中等水平抗性和高水平抗性。对LC_(50)处理下存活二斑叶螨的解毒酶活性分析表明,抗性种群的谷胱甘肽-S-转移酶(GSTs)和尿苷二磷酸糖基转移酶(UGTs)的活性最高,田间种群次之,并均显著高于敏感种群的酶活性,与用药前相比,用药处理后高抗种群和田间中抗种群的酶活性均随着处理时间的延长而提高,而敏感种群的酶活性显著被抑制。采用荧光定量PCR比较上述解毒酶的编码基因表达量差异,发现用药处理后,GSTm09、GSTd10和UGT204a2、UGT201d3基因在高抗种群和田间中抗种群的表达量显著高于敏感种群,并随着处理时间的延长,抗性种群和敏感种群的解毒酶基因表达的差异倍数进一步增大。相关性分析表明,解毒酶活性及其编码基因表达与阿维菌素的抗性水平呈显著正相关。本研究结果为深入挖掘二斑叶螨抗性靶标基因和研发抗性治理策略提供理论参考。

ABAMECTIN与Bt制剂复配的杀虫增效作用

以菜青虫为试虫测定abamectin与Bt8010复配的毒力。结果表明abamectin—Bt8010的5种不同配比均有不同程度的增效作用,其中以5000IUBt8010+0.1％abamectin的增效作用最为显著,其共毒系数为289.4.室内药效测定结果,用该配比制成的可湿性粉剂对花椰菜、白菜、番茄、豌豆、蚕豆、茶树、柑桔、马尾松8种植物上分属鳞翅目、同翅目、鞘翅目、双翅目和蜱螨目的23种害虫有较好的杀灭效果。混配制剂对鳞翅目幼虫仅能提高用药24h后的杀灭率,并不能提高24h内的杀灭速度。

家蝇对Abamectin的抗性

<正> Abamectin是一组具有强大杀螨、杀虫、杀线虫活性的十六员大环内酯,是一种土壤放线菌Strepto-mycesavermitilis的天然发酵产物,即四种极相似的同系物:AbamectinA1,A2,B1和B2。其中Abamect-inB1（Abamectin,MK-936）是从液体发酵产物中分离

Efficacy Evaluation of 25% Abamectin·Etoxazole SC against Red Spider (Tetranychus cinnbarinus ) in Ornamental Rose

[Objective]The paper was to understand the control effect and the optimum dosage of 25% abamectin·etoxazole SC for controlling red spider in ornamental rose. [Method] Using stem-leaf spraying method,the control effect of 25% abamectin·etoxazole SC against red spider was determined. Significance of difference was examined by Duncan's new multiple range test( DMRT). [Result] The control effect of 25% abamectin · etoxazole SC sprayed at the dose of25-31. 25 mg a. i./kg on red spider was over 82. 0% at 21 d post spraying,higher than that of 110 g/L etoxazole SC sprayed at the dose of 27. 5 mg a. i./kg and1. 8% abamectin EC sprayed at the dose of 9 mg a. i./kg. [Conclusion]25% Abamectin·etoxazole SC sprayed at the doses of 25-31. 25 mg a. i./kg could effectively control the damage of red spider in ornamental rose,and can be widely used in production.

Effect Trials on Abamectin + Chlorpyrifos 8% GR for Controlling Turf Grubs

To screen high-efficiency, low-toxicity, and safe pesticides for controlling soil pests, experimental investigations of Abamectin ＋ Chlorpyrifos 8 % GR for controlling tuff grubs were implemented according to Field Pharrnacodynamic Test Standards of the Ministry of Agricuhure. The results showed that as the active in- gredient of Abamectin ＋ Chlorpyrifos 8% GR is 1 625 - 1 950 g/hm2, the control efficiency of tuff grubs is 81.43% -90.46% 3 - 10 days after pesticide applica- tion, the readily availability and persistent effect achieve the ideal level, and it is safe for turf.

In vitro Acute Cytotoxicity of Abamectin to the Gill Cell Line of Flounder Paralichthy olivaceus

The cytotoxicity of abamectin to the Gill Cell Line of Flounder （FG cell line） was examined in this study. It was found that the exposure of FG cells to abamectin caused the decreases of both cell growth rate and antioxidant enzyme activities, and the increase of intracellular 02 content. It was proposed that the reduction of antioxidant enzyme activities in FG cells caused the accumulation of 02 content in FG cells, leading to the change of cell morphology and even the death of cells. The results showed that FG cell line is suitable for the evaluation of the acute toxicity of abamectin.

噻唑膦与硅肥联合使用对甘薯茎线虫病的防治效果

为了有效控制甘薯茎线虫病的危害,通过盆栽试验和田间试验分别研究了不同种类硅肥及噻唑膦对甘薯茎线虫病的防控效果。室内试验结果表明,单独施用硅肥对甘薯茎线虫病防治效果较差,但10%噻唑膦颗粒剂与不同种类硅肥联合使用后可显著降低甘薯种薯及薯苗受线虫侵染率,其效果优于单独使用等量的10%噻唑膦颗粒剂。田间施用噻唑膦后再增施硅肥,可使噻唑膦防治效果显著增高,甘薯受害率降低,甘薯产量提高。其中硅肥途保佳15 L/hm^(2)与10%噻唑膦颗粒剂18 kg/hm^(2)或22.5 kg/hm^(2)联合使用后,对茎线虫病的防治效果均达到87%以上,显著高于10%噻唑膦颗粒剂22.5 kg/hm^(2)处理。联合施用硅肥可以在减少噻唑膦用量情况下保持对茎线虫病较高防效,具有较好的推广应用前景。

Lack of fitness cost and inheritance of resistance to abamectin based on the establishment of a near-isogenic strain of Tetranychus urticae

Many populations of the two-spotted spider mite, Tetranychus urticae Koch, have developed high levels of resistance to the pesticide abamectin in China and other countries. This study developed a near-isogenic line to understand better the inheritance, cross-resistance, and fitness costs associated with abamectin resistance in the field population of T. urticae in China. We introduced the trait that confers extremely high abamectin resistance in a field-collected population of T. urticae into a susceptible laboratory strain(IPP-SS) to generate an abamectin-resistant near-isogenic line(NIL-Aba).This process was carried out through multiple backcrossing to IPP-SS and via parthenogenesis and abamectin screening. Compared with IPP-SS, the NIL-Aba strain had a 25 147-fold resistance to abamectin and a high level of cross-resistance to bifenthrin(288.17-fold), an intermediate level to emamectin benzoate(42.57-fold), and low levels to bifenazate, chlorfenapyr, cyflumetofen, cyenopyrafen, and cyetpyrafen with resistance ranging from 3.18-to 9.31-fold.But it had no cross-resistance to profenofos. The resistance to abamectin in NIL-Aba was autosomal, incompletely dominant, and polygenic. Based on two sex life table parameters, no fitness cost was found in NIL-Aba. Establishing the NIL-Aba strain provides a reliable basis for an in-depth study of abamectin resistance in T. urticae. New information on toxicological characteristics and fitness cost should facilitate the management of abamectin resistance in field populations of T. urticae.

Short-Time Derivatization Method for Analysis of Abamectin in Water Using High-Performance Liquid Chromatography Coupled to Fluorescence Detector

A method using a short-time derivatization step for the assessment of abamectin in water is presented. Abamectin derivative stable up to 7 days was obtained. Some regions where orange crops are present have received abamectin doses, aiming to increase the productivity and to combat pests and weeds, even when its residues reach the aquatic environment and interfere on water quality. Water samples from Jacaré-Pepira River (Brotas City, Brazil) nearby orange crops around urban zone, were evaluated for the presence of abamectin. The analytical method was validated resulting recovery around 108%, precision of 12%, accuracy of 104%, correlation coefficient of 0.9945, and detection and quantification limits of 0.1 μg·L﹣1 and 0.2 μg·L﹣1, respectively. Stable abamectin derivative was reached after 60 min of derivatization at room temperature (25&deg;C). No abamectin residues were found into samples.

基于HPLC-UV-QDa检测不同剂型中噻唑膦和吡虫啉

建立了高效液相色谱-紫外检测器-质谱(HPLC-UV-QDa)测定5种不同剂型产品中噻唑膦和吡虫啉含量的分析方法。样品以乙腈+水(0.05%甲酸)为流动相,采用C18色谱柱进行梯度洗脱,结合紫外和质谱串联检测器进行定性和定量分析。研究结果显示,在质量浓度0.05~50 mg/L,噻唑膦、吡虫啉的线性关系良好,R2分别为0.9992~0.9999和0.9991~0.9996。在0.5、50、500 mg/kg等3个添加水平下,噻唑膦、吡虫啉的平均回收率分别为90.2%~103.9%和94.7%~104.1%,相对标准偏差(RSD)分别为1.04%~6.69%和1.27%~5.88%。噻唑膦和吡虫啉在5种基质中无明显基质效应,检出限分别为0.005和0.01 mg/L,定量限分别为0.02和0.04 mg/kg。方法灵敏度高、稳定性好、准确度高,适用于不同剂型产品中噻唑膦和吡虫啉的分析。

寡糖联合淡紫紫孢菌对化学杀线剂防治烤烟根结线虫病效果的影响

为更好地控制烟草根结线虫的危害,降低化学杀线剂的用量,将寡糖免疫诱导剂与噻唑膦、阿维菌素及淡紫紫孢菌协同使用进行田间小区试验,研究其对烟草根结线虫的防治效果。结果表明,壳寡糖15 L/hm^(2)、几丁寡糖15 L/hm^(2)分别与噻唑膦22.5 kg/hm^(2)协同使用,对烟草根结线虫的防治效果高于噻唑膦单独使用效果。相对防效由噻唑膦单独使用的45.20%分别提高到64.42%和65.38%。进一步试验发现,几丁寡糖1 kg/hm^(2)、淡紫紫孢菌15 kg/hm^(2)及噻唑膦16.875 kg/hm^(2)(减少25%)协同使用,对烟草根结线虫病相对防效及对烟草生长总体效应优于与噻唑膦正常用量(22.5 kg/hm^(2))组和噻唑膦减少50%(11.25 kg/hm^(2))组合效果。寡糖诱导剂单独或与淡紫紫孢菌协同使用,显著提高了噻唑膦对烟草根结线虫病的防治效果,减少了农药使用量,为烟草根结线虫病害的防控提供了一种新的技术手段。

亚致死浓度阿维菌素和毒死蜱对经历寄主转换的稻纵卷叶螟生长发育和繁殖的影响

【目的】本研究旨在明确寄主转换经历是否会改变亚致死浓度杀虫剂对稻纵卷叶螟Cnaphalocrocis medinalis生长发育和繁殖的影响,为杀虫剂的合理使用及稻纵卷叶螟的综合治理提供理论依据。【方法】从稻纵卷叶螟水稻种群和小麦种群中收集卵,并将其分别转换寄主植物饲养至2龄,作为具有不同寄主转换经历处理的幼虫[以水稻为食的水稻种群(R-R)、以小麦为食的水稻种群(R-W)、以小麦为食的小麦种群(W-W)和以水稻为食的小麦种群(W-R)]。利用离体叶片浸渍法对这些幼虫在亚致死浓度(LC_(25))阿维菌素和毒死蜱浸渍下的水稻或小麦叶片处理后48 h,测定3-5龄幼虫生长发育及成虫繁殖能力和寿命。【结果】未经杀虫剂处理时,寄主转换显著影响稻纵卷叶螟3-5龄幼虫总历期、化蛹率和蛹重,但对水稻种群和小麦种群的影响相反。LC_(25)浓度阿维菌素和毒死蜱处理2龄幼虫,显著延长3-5龄幼虫总历期,但延长程度因寄主转换经历而异。LC_(25)浓度阿维菌素显著降低各寄主转换经历幼虫的化蛹率(R-R组除外)。LC_(25)浓度毒死蜱仅显著降低W-W组的化蛹率。在2龄幼虫暴露于LC_(25)浓度阿维菌素后W-W和W-R组的蛹重显著降低。水稻种群化蛹率和蛹重受寄主转换的影响在LC_(25)浓度阿维菌素处理后消失,而小麦种群化蛹率和蛹重受寄主转换的影响在LC_(25)浓度阿维菌素和毒死蜱处理后均消失。无论是何种寄主转换经历还是LC_(25)浓度阿维菌素和毒死蜱处理均未影响成虫羽化率、交配率和单雌产卵量。寄主转换处理只显著影响未经杀虫剂处理时水稻种群的卵孵化率,但卵孵化率均未受LC_(25)浓度阿维菌素和毒死蜱处理影响。与未经杀虫剂处理相比,LC_(25)浓度阿维菌素和毒死蜱处理均未影响雌成虫寿命,但LC_(25)浓度毒死蜱处理显著增加了W-W组雄成虫寿命。【结论】寄主转换经历会影响阿维菌素和毒死蜱对稻纵卷叶螟的亚致死效应。LC_(25)浓度阿维菌素和毒死蜱处理经历寄主转换的稻纵卷叶螟幼虫后,其幼虫和蛹生长发育均受到不同程度影响,但成虫繁殖和寿命所受影响较小。使用针对稻纵卷叶螟的杀虫剂时和进行毒理实验时应考虑到寄主植物的潜在影响。

鲤在阿维菌素胁迫下肝胰腺组织的转录组分析

为了探究阿维菌素胁迫对鲤机体的响应机制,在水温(22±2.0)℃,将体质量(150±30)g的鲤(Cyprinus carpio)分别暴露在阿维菌素浓度0μg·L^(-1)(对照组)、1.5μg·L^(-1)和3.0μg·L^(-1)下5 d,采用转录组学测序分析方法,探究阿维菌素胁迫对鲤肝胰腺转录组学的影响,解析其对鲤的分子毒理机制。通过对所得基因的功能注释发现,被注释的差异基因主要与结合、催化和代谢等功能有关。KEGG通路富集分析结果显示,差异表达基因在药物代谢-细胞色素P450、药物代谢-其他酶、淀粉和蔗糖代谢等通路中显著富集,涉及药物代谢、氨基酸代谢、碳水化合物代谢、脂质代谢以及辅助因子和维生素的代谢等多个代谢过程。这些功能基因和预测通路为理解阿维菌素胁迫鲤体内解毒和免疫系统奠定了基础。本研究获得的转录组数据可为深入研究鱼类应对杀虫剂污染物的分子机制提供丰富的基因资源。

生防菌剂与噻唑膦减量配施对番茄根结线虫及根际土壤微生物的影响

减少化学农药的使用,提高生物农药在田间使用效率对实现化学农药减施及农产品质量安全具有重要意义。本研究以番茄‘新金丰一号’为试验材料,采用盆栽接种根结线虫的方法研究噻唑膦与生防菌剂以不同剂量配施对番茄根结线虫的防效及对根际土壤微生物的影响。结果表明:噻唑膦减量50%配施50%生防菌剂处理后,土壤中的根结线虫数量和番茄根系的根结指数相比单独使用噻唑膦或生防菌剂及清水处理均显著降低,番茄移栽后60 d,根结线虫减退率为49.61%,根结指数为32.50,防治效果达64.77%。与仅用噻唑膦处理相比,噻唑膦减量50%配施50%生防菌剂处理还显著增加了番茄根际土壤中可培养细菌、放线菌数量及微生物的总量,其中细菌和放线菌数量较仅用噻唑膦处理增加76.21%和47.96%,微生物总量增加69.60%。此外,放线菌门、子囊菌门的相对丰度也显著增加,而酸杆菌门和芽胞杆菌门的相对丰度则正好相反。无论使用生防菌剂还是噻唑膦减量配施生防菌剂均显著增加了番茄根际土壤中髌骨细菌门、浮霉菌门和木霉属的相对丰度,但仅使用噻唑膦处理则显著降低了木霉属的相对丰度。综上,噻唑膦减量50%配施50%生防菌剂可通过增加番茄根际土壤中可培养微生物数量及放线菌门和木霉属等有益微生物的丰度来提高对番茄根结线虫的防效。

间甲氧基苯甲酸和噻唑膦复配对土传病原微生物的联合毒力评价

为筛选出更适合作物土传病害防治的高效农药品种,在室内条件下分别测定了间甲氧基苯甲酸与噻唑膦单剂及其复配对青枯雷尔氏菌、尖孢镰刀菌和根结线虫的毒力,并采用Wadley法对复配药剂的联合毒力进行评价。结果表明,不同复配比混合物对土传病原物的活性有所差异。间甲氧基苯甲酸与噻唑膦体积比为1∶1时,对青枯雷尔氏菌和南方根结线虫的增效作用最强,增效系数SR分别为1.67和1.83;而该体积比下对尖孢镰刀菌的SR同样最高,为1.16,表现为相加作用。间甲氧基苯甲酸和噻唑膦按体积比1∶1复配可用于防治土传病原微生物引起的植物病害。