Baseline susceptibility of Haemaphysalis longicornis to organophosphate,carbamate, and pyrethroid acaricides

BACKGROUND

The Asian longhorned tick, Haemaphysalis longicornis, continues to expand its range in North America, and synthetic acaricides are likely to play an increasing role in managing this species. Acaricide resistance is common in some tick species that infest livestock. However, baseline acaricide susceptibility has not previously been examined in this invasive tick.

RESULTS

We used a standard larval packet test to evaluate the susceptibility of the Asian longhorned tick to acaricides currently or formerly used in tick control: propoxur, carbaryl, bifenthrin, permethrin, and coumaphos. Discriminating concentrations were estimated at 6.5, 27.9, 988, 2242, and 808 ppm, respectively. The half-maximal lethal concentration (LC₅₀) values for propoxur, carbaryl, permethrin and coumaphos were compared with data available for other tick species and showed that H. longicornis was more susceptible to propoxur, carbaryl and coumaphos, and had a similar susceptibility to permethrin.

CONCLUSIONS

The results indicate that resistance to these acaricides is not currently a concern for H. longicornis in the United States. However, responsible integrated management and early detection of resistance can help ensure the long-term efficacy of products used for controlling this tick species. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

降解氨基甲酸乙酯酿酒酵母的筛选及其应用

以宁夏5个产区的酿酒葡萄为原料筛选可以降解氨基甲酸乙酯（Ethyl carbamate,EC）且具有优良酿酒特性的红葡萄酒和白葡萄酒酿酒酵母。初筛试验获得了10株酵母,复筛试验以EC作为唯一氮源筛选出6株EC降解能力较好的酵母菌株,最后通过产气试验和耐受性试验筛选出了2株发酵性能较好的菌株。经过18S rDNA分子生物学鉴定后确定这2个菌株为酿酒酵母。使用筛选出的2个菌株发酵红葡萄酒和白葡萄酒,并以商业酵母作为对照,测定其理化指标及EC含量;再通过GC-MS分析其香气物质并结合感官评价最终筛选出具有优良酿酒特性和降解EC功效的红葡萄酒酿酒酵母（Saccharomyces cerevisiae）NXSC2和白葡萄酒酿酒酵母（Saccharomyces cerevisiae）NXSC1。     

气相色谱-串联质谱法测定豆乳中12种有机磷及氨基甲酸酯类农药残留

建立QuEChERS-气相色谱-串联质谱法测定豆乳中12 种有机磷及氨基甲酸酯类农药残留的方法。样品经乙腈提取,柠檬酸盐缓冲条件下分离,无水硫酸镁、乙二胺-N-丙基硅烷化硅胶和C18净化处理,气相色谱-串联质谱仪测定。结果表明：12 种农药的定量限均为0.004 mg/kg;标准曲线在5～200 ng/mL范围内线性良好,相关系数＞0.99;进行3 个不同水平的加标实验,加标回收率为71.8%～114.9%,相对标准偏差为4.6%～13.3%。该方法快速、高效、准确,可用于豆乳中有机磷及氨基甲酸酯类农药残留的测定。     

紫甘蓝中氨基甲酸酯类农药多残留分析方法研究

建立了高效液相色谱柱后衍生法测定紫甘蓝中 9种氨基甲酸酯类农药及 2种代谢物残留量的方法。采用C18、PSA小柱固相萃取分离净化, 用ODS柱 (柱槽温度 50℃) 在梯度淋洗条件下对 9种氨基甲酸酯类农药及 2种代谢物进行分离, 通过柱后衍生化, 荧光检测器 (荧光波长为 445nm) 定性定量测定紫甘蓝中 9种氨基甲酸酯类农药及 2种代谢物(杀线威、灭多威、涕灭威、恶虫威、甲萘威、硫苯威、硫双灭多威、仲丁威、甲硫威、甲硫威代谢物 1、甲硫威代谢物2) 的残留量。结果表明, 9种农药及 2种代谢物在 28min内可以得到很好的分离, 线性范围为 0 01~50mg·L-1, 线性相关系数R2≥0 998 0, 检出限为 0 70~5 0μg·L-1, 方法回收率为 80 6% ~103 3%。     

甲氧基丙烯酸酯类制剂的木材防腐性能研究

目的木材防腐处理是延长木材使用寿命,减少森林砍伐,保护生态环境的有效方法。本研究对甲氧基丙烯酸酯类杀菌剂、碘代丙炔基丁基氨基甲酸酯(IPBC)和4,5-二氯正辛基-4-异噻唑啉-3-酮（DCOIT）的防腐性能进行了系统测试,旨在筛选出生态友好型木材防腐制剂,丰富木材防腐剂体系。方法采用抑菌圈法测试嘧菌酯、醚菌酯、吡唑醚...     

气相色谱-质谱法测定发酵乳中氨基甲酸乙酯含量

采用气相色谱-质谱法定量,建立测定发酵乳中氨基甲酸乙酯含量的分析方法。通过优化前处理条件,同时考察方法的线性关系、精密度、加标回收率、检出限及定量限等指标,内标法定量。结果表明：该方法在0～200?ng/mL范围内线性良好（r＞0.999）,氨基甲酸乙酯检出限为2.0?μg/kg,定量限为5.0?μg/kg,加标回收率为89.9%～105.2%,相对标准偏差小于10%。该方法灵敏、准确、重复性好,能满足发酵乳中氨基甲酸乙酯含量的测定要求。     

氨基甲酸乙酯麻醉对家兔生理指标的影响

[目的]研究氨基甲酸乙酯麻醉后家兔呼吸频率、体温和心率的变化规律。[方法]以大耳白兔为研究对象,研究氨基甲酸乙酯麻醉对家兔呼吸频率、体温和心率的影响。[结果]氨基甲酸乙酯麻醉10 min后,家兔呼吸频率下降50%,与麻醉前差异在0.05水平显著,此后呼吸频率呈缓慢下降趋势。麻醉后家兔体温开始下降,45 min后达到最低值(37.0℃),与麻醉前差异在0.05水平显著,此后体温略有上升。麻醉后家兔心率总体上呈降-升-降的趋势,20 min后家兔心率降至206次/min,此后心率有所升高,但麻醉45 min后心率又呈下降趋势。[结论]氨基甲酸乙酯麻醉后,家兔呼吸频率、体温和心率均有所降低。该研究为生理试验中麻醉剂的选择提供参考依据。     

高效液相色谱柱后衍生化法检测蔬菜中氨基甲酸酯类杀虫剂农药残留

本文建立蔬菜中多种氨基甲酸酯类杀虫剂残留分析方法。样品以丙酮、二氯甲烷混合溶剂提取，以活性炭/Celite545柱净化，以高效液相色谱柱后衍生系统、荧光检测器检测。方法最低检出浓度1-2μg/kg,添加回收率70%-111.1%，相对标准偏差2.02%-12.09%。     

A novel immobilized cholinesterase for on-site screening of organophosphate and carbamate compounds

Acetylcholinesterase was physically adsorbed on polyvinylpyrrolidone K30 to prepare a novel immobilized cholinesterase, which was described for the first time. The immobilized enzyme was tested for its reactivity, enzyme activity stability, the solubility, the influence of pH and buffer, and characteristic reactivity with inhibitors, e.g., organophosphate and carbamate compounds. The result revealed that the immobilized cholinesterase held its original activity in solution, stable enough, easy to dissolve for convenient operation, and this immobilized cholinesterase could be well used for rapid, on-site screening of organophosphate and carbamate compounds, together with a portable pesticide analyzer.