High level of metaflumizone resistance and multiple insecticide resistance in field populations of Spodoptera exigua (Lepidoptera: Noctuidae) in Guangdong Province,China

Spodoptera exigua is a phytophagous pest that causes critical economic losses in vegetable crops, and insecticides are commonly used against it in vegetable growing areas. However, excessive and frequent applications of insecticides cause resistance in S. exigua. The current resistance in field populations of S. exigua collected from Huizhou, Guangdong Province, China to 12 insecticides was investigated. S. exiguahad developed very high resistance to lambda cyhalothrin (2925- to 3449-fold), chlorpyrifos (>1786-fold), emamectin benzoate (174- to 867-fold), and metaflumizone (60.3- to 942-fold). High resistance to tebufenozide (51.5- to 75.4-fold) and chlorfluazuron (60.4- to 63.0-fold) was also found. Synergism assays revealed that the resistance to metaflumizone and lambda cyhalothrin was associated with esterase and microsomal oxidases, respectively. The resistance to emamectin benzoate was not affected by detoxification enzymes inhibitors and might be conferred by other mechanisms. The selection of the field population by metaflumizone for 10generations in the laboratory resulted in a 6.1-fold increase in metaflumizone resistance but did not lead to increases in resistance to other insecticides. After metaflumizone selection, susceptibilities to spinosad and endosulfan did not change, and the susceptibilities to indoxacarb, methomyl, pyridalyl, tebufenozide, chlorfluazuron, emamectin benzoate and lambda cyhalothrin decreased slightly. However, no statistically significant differences in the resistance levels were observed among the selected population, its starting strain and the unselected strain. The resistance to chlorantraniliprole noticeably decreased in unselected strain and the strain subjected to selection for 10 generations compared with their starting strains. Lack of cross-resistance to tested insecticides suggested the involvement of multiple mechanisms of resistance and the need for wise application of these insecticides for the management of S. exigua.     

Intravaginal administration of estradiol benzoate capsule for estrus synchronization in goats

Estrus synchronization requires multiple treatments of hormonal drugs, requiring considerable time and cost. The aim of the present study was to develop an estrus synchronization protocol using intravaginal administration of estradiol benzoate (EB) capsules in goats. Two types of capsules were prepared: an EB capsule that melted immediately after administration and a sustained-release (SR) EB capsule that dissolved slowly and reached a peak after 24 h. Goats with functional corpus lutea were intramuscularly treated with prostaglandin F_2α (PG). At 24 h after PG administration, goats were administered 1 mg of EB solution intramuscularly (PG + 24IM; n = 6) or 1 mg of EB capsule intravaginally (PG + 24EB; n = 6). The SR EB capsule was administered intravaginally at the time of PG administration (PG + SR; n = 6). The control group (n = 6) received only PG. All groups showed estrus within 72 h after PG administration. The onset of estrus did not differ significantly between the PG + 24IM and PG + SR groups but was earlier than in the control group. Estradiol concentration in the PG + SR group peaked at 11.5 ± 6.1 h after EB and PG administration. Peak estradiol concentrations were not significantly different between the PG + 24IM and PG + SR groups (78.0 ± 25.8 and 64.0 ± 38.1 pg/ml, respectively), and were higher than the PG + 24EB and control groups (27.3 ± 8.8 and 14.6 ± 6.1 pg/ml, respectively). These results suggest that intravaginal administration of an EB capsule with a sustained-drug release base is applicable for estrus synchronization, as an alternative to intramuscular administration.     

甲氨基阿维菌素苯甲酸盐研究进展

大环内酯类杀虫剂甲氨基阿维菌素苯甲酸盐(简称为甲维盐)以昆虫γ-氨基丁酸(GABA)和谷氨酸作为作用靶标。作者就甲维盐的理化性质、作用机制、害虫对甲维盐的抗性、交互抗性和抗性机制、甲维盐剂型、原药的致突变性及亚慢性毒性、中毒救治、分析方法和残留动态进行了综述。     

防腐剂浸种对玉米种子萌发及幼苗生长的影响

采用水培法研究了不同浓度苯甲酸钠、山梨酸钾浸种对玉米种子萌发和幼苗生长的影响,初步探讨了防腐剂对作物生长造成的危害。结果显示:2种防腐剂浸种对玉米种子的萌发均呈现明显的抑制作用,当苯甲酸钠和山梨酸钾含量分别为1.0%、0.3%时,玉米种子发芽势和发芽率均由对照组的96.67%降至80%以下;幼苗的形态指标和生理指标测定值也均有显著变化。因此,2种防腐剂对玉米种子萌发和幼苗生长均呈现抑制作用。     

甲维盐·多杀菌素3%乳油高效液相色谱分析

本文采用高效液相色谱法,以甲醇＋乙腈＋水（0.5%乙酸钠）为流动相,使用Nova-Pak C18 4μm为填料的不锈钢柱和紫外波长检测器,检测波长250nm,对甲维盐.多杀菌素3%乳油进行了定量分析。结果表明,方法的标准偏差分别为0.007、0.019,变异系数为0.575%、0.790%,平均回收率为100.10%、100.43%,线性相关系数为0.999、0.998。     

ETP对苹果小卷叶蛾的毒力测定

作者测定了保幼激素类似物ETP即4—[2—(特丁基甲酰氧基)丙氧基]苯甲酸乙酯对苹果小卷叶蛾(Adoxophyes orana)的毒理效应,其作用主要表现在以下两方面:①ETP处理幼虫,使变态异常产生了幼虫一蛹中间体,以不正常蛹等级率为指标的半有效剂量分别为:点滴ED_(50)=29.80μg/头、幼虫饲喂EC_(50)=161.57mg/L、田间喷洒EC_(50)=1075mg/L;②ETP处理幼虫,使雌蛾产卵力明显下降,其半有效剂量分别为:点滴ED_(50)=9.58μg/头、幼虫饲喂EC_(50)=206.7mg/L、田间喷洒EC_(50)=914mg/L。     

甲胺基阿维菌素苯甲酸盐研究概述

本文介绍了甲胺基阿维菌素苯甲酸盐的研究概况，包括其理化性质、原药和残留分析方法以及合成方法。并介绍了使用甲维盐的方法、抗性治理、注意事项及急救措施。     

Thioester-Containing Benzoate Derivatives with α-Glucosidase Inhibitory Activity from the Deep-Sea-Derived Fungus Talaromyces indigoticus FS688

Eurothiocins C–H (1–6), six unusual thioester-containing benzoate derivatives, were isolated from the deep-sea-derived fungus Talaromyces indigoticus FS688 together with a known analogue eurothiocin A (7). Their structures were elucidated through spectroscopic analysis and the absolute configurations were determined by X-ray diffraction and ECD calculations. In addition, compound 1 exhibited significant inhibitory activity against α-glucosidase with an IC₅₀ value of 5.4 μM, while compounds 4 and 5 showed moderate effects with IC₅₀ values of 33.6 and 72.1 μM, respectively. A preliminary structure–activity relationship is discussed and a docking analysis was performed.     

0.2%高渗甲氨基阿维菌素苯甲酸盐微乳剂防治甘蓝甜菜夜蛾田间药效试验

对0.2％高渗甲氨基阿维菌素苯甲酸盐微乳剂防治甘蓝甜菜夜蛾进行了田间药效试验。结果表明：0．2％高渗甲氨基阿维菌素苯甲酸盐微乳剂40ml／667m^2的剂量,对甘蓝甜菜夜蛾具有良好的防效,药后7d杀虫效果达97％以上。     

苯甲酸盐水剂防除金钟藤试验研究

在秋季,应用苯甲酸盐水剂对金钟藤进行挂瓶滴加的防除试验,结果表明:5%的苯甲酸盐水剂滴加24~36 h最经济有效,防除金钟藤效果达100%;用药量与金钟藤藤茎的直径成正比。在1~6 cm藤茎范围内,用药量在50~200 m l范围增减。