阿维菌素在3种十字花科蔬菜中的残留消解动态

为探明阿维菌素在十字花科蔬菜芥蓝、叶芥菜和芜菁中的残留消解行为和安全性,建立了高效液相色谱测定3种蔬菜中阿维菌素残留量的分析方法。样品经丙酮提取,C18柱净化,高效液相色谱-紫外检测器检测,外标法定量;运用所建立的方法对阿维菌素在山东烟台、河北保定、浙江绍兴、贵州贵阳、黑龙江哈尔滨和安徽宿州6个试验点的芥蓝、叶芥菜、芜菁中的残留消解动态和最终残留量进行了研究。结果表明:阿维菌素在芥蓝、叶芥菜和芜菁中的消解速率很快,半衰期分别为0.3~0.6、2.2~3.1和0.8~1.0 d,其残留量随时间延长而递减,符合一级反应动力学方程,属易消解型农药。     

Genetic basis of resistance and studies on cross-resistance in a population of diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae)

The genetic basis of abamectin resistance was studied in a strain of the diamondback moth, Plutella xylostella (L), following laboratory selection of a field population collected at Xuanhua, Hebei Province, China. Data from the testing of F1 progeny from reciprocal crosses between abamectin-resistant and abamectin-susceptible strains indicated that resistance might be autosomal and incompletely recessive with a degree of dominance of -0.13. Chi-squared analyses from the response of a backcross of crossed F1 progeny and the resistant strain and F2 progeny were highly significant, suggesting that the resistance was probably controlled by more than one gene. The results of cross-resistance studies showed that there was little cross-resistance between abamectin and four pyrethroid insecticides (deltamethrin, beta-cypermethrin, fenvalerate and bifenthrin) and no cross-resistance between abamectin and the acylureas chlorfluazuron or flufenoxuron.     

小菜蛾对阿维菌素抗药性的研究进展

小菜蛾是在世界范围内最难防治的害虫之一,小菜蛾对阿维菌素的抗性是目前十字花科蔬菜生产中的突出问题.现主要综述了小菜蛾对阿维菌素抗性现状、交互抗性、抗性机理方面的研究进展,以期对其抗性治理提供参考.     

朱砂叶螨的抗药性选育及其解毒酶活性研究

在室内模拟田间药剂的选择压力,用阿维菌素和甲氰菊酯对朱砂叶螨Tetranychus cinnabarinus 进行逐代处理,以选育其抗药性品系。阿维菌素品系选育至42代,抗性增长到8.7倍,甲氰菊酯品系选育至40代,抗性增长到68.5倍。阿维菌素抗性品系羧酸酯酶(CarE)、谷胱甘肽-S-转移酶(GSTs)、多功能氧化酶(MFO)的活性分别为敏感品系的2.7、3.4和1.4倍,差异达显著水平。推测3种解毒酶活性显著升高是朱砂叶螨对阿维菌素产生抗性的重要原因。甲氰菊酯抗性品系GSTs的活性为敏感品系的2.8倍,差异显著,表明该抗性品系的形成与GSTs活性增强有关。羧酸酯酶动力学测定结果表明,朱砂叶螨阿维菌素抗性品系体内存在变构的羧酸酯酶。     

阿维菌素与蚜虱净混配防治中国梨木虱药效试验

为克服梨木虱对单一药剂长期使用产生抗性以及高毒农药对环境的污染,研究阿维菌素与蚜虱净的混配药剂对梨木虱的防治效果。结果表明:阿维菌素与蚜虱净混配防治梨木虱,具有良好的速效性和持效性;药后1 d的防治效果为87.1%,高于各单剂和对照药剂;药后15 d的防治效果为93.2%,显著高于单剂10%吡虫啉WP 1 000倍和对照药剂40%水胺硫磷EC1 000,与1.8%阿维菌素EC 2 000倍差异不显著,但阿维菌素与蚜虱净混配扩大了杀虫谱。     

树干注药技术预防松材线虫病的效果评价

松材线虫病是松林的毁灭性病害,过去几十年已在日本、韩国及中国等东亚国家迅速传播扩散.加强对非疫区的监测与保护是目前关注的重点,利用1％阿维菌素微囊悬浮剂对马尾松进行树干注药以预防松材线虫病,研究结果表明,树干注药处理区的枯死松树要显著少于不实施注干的对照区,且处理区内枯死松树比率不超过2％.因此,通过树干注药技术施用1％阿维菌素微囊悬浮剂对预防松材线虫病能起到显著效果.     

菜豆中阿维菌素残留量的高效液相色谱检测方法及消解动态研究

建立了反相高效液相色谱法测定菜豆中阿维菌素残留量的方法,以乙酸乙酯为提取剂,液液萃取净化,经N-甲基咪唑和三氟醋酸酐衍生化,采用高效液相色谱法-荧光检测器(激发波长365 nm,发射波长为470 nm)进行测定。同时,为确定1%阿维菌素水乳剂在菜豆中的施用安全性,通过两年两地田间试验和样品室内检测试验,研究了其在菜豆上的消解动态及最终残留量。试验结果表明：在0.05~5.0 μg/mL浓度范围内,阿维菌素的浓度与峰面积线性关系良好,线性相关系数γ为0.9997。添加浓度在0.0044~0.44 mg/kg 时,方法的平均回收率为94.35~99.42%,相对标准偏差为4.81~5.84%；以1%阿维菌素水乳剂0.45 g/m²喷药,阿维菌素在菜豆上的消解半衰期为1.4~1.7 d；施药7 d后采集的菜豆样品中阿维菌素含量均低于0.05 mg/kg (中华人民共和国农业行业标准NY1500.1.3-2007规定阿维菌素在豇豆中的最大残留限量,即MRL值,本文以此作为菜豆中阿维菌素的推荐MRL值)。本方法简便、快速、准确,适用于阿维菌素在菜豆上的残留量测定。     

Persistent efficacy of abamectin and doramectin against gastrointestinal nematodes of cattle

Objective To assess the persistent activity of injectable formulations of abamectin and doramectin against gastrointestinal nematodes of cattle.
Design Controlled slaughter study assessing residual efficacy.
Procedure Nematode-free calves were treated with abamectin or doramectin (each at a dose of 200 μg/kg) and infections then induced with repeated doses of infective larvae of Trichostrongylus axei, Haemonchus placei, Ostertagia ostertagi and Cooperia species. The duration of challenge ranged from 14 to 28 days. The calves were slaughtered at either 38/39 or 45/46 days after the treatments and nematodes recovered from the gastro-intestinal tract.
Results Significant reductions in numbers of O ostertagi occurred for both abamectin and doramectin treatments (> 93%) relative to counts in untreated calves, when challenge was administered up to 21 days after treatment. For T axei and Cooperia spp significant reductions occurred when the challenge occurred for 14 days after treatment (99%). Although differences from untreated animals were not significant, the results for H placei suggested high efficacy (> 85%) for up to 21 days for doramectin and up to 28 days for abamectin.
Conclusion There was no significant difference between abamectin and doramectin for any parasite at any challenge point, indicating that there is equivalent persistent activity of doramectin and abamectin against important gastrointestinal nematodes of cattle.     

阿维菌素·哒螨灵10.5%乳油防治苹果红蜘蛛田间药效试验

对阿维菌素.哒螨灵10.5%乳油防治苹果红蜘蛛进行了田间药效试验,结果表明,阿维菌素.哒螨灵10.5%乳油对苹果红蜘蛛具有理想的防治效果,药后3d,2 000倍液的防效高达94.8%,在苹果红蜘蛛发生初期用药1次,持效期可达10d以上,且对苹果树生长无不良影响,安全性好。     

0.8％阿维菌素微胶囊悬浮剂对蔬菜几种主要害虫的毒力和田间药效

室内生测结果表明,0.8％阿维菌素微胶囊悬浮剂对斜纹夜蛾、小菜蛾、菜粉蝶的LC50分别为27.72、1.69、0.85 mg/L,与乳油剂型的毒力相当。持效性试验结果显示,0.8％阿维菌素微胶囊悬浮剂的持效性要优于乳油剂型,在1～14 d内表现尤为明显。对小菜蛾、菜粉蝶的田间药效试验表明,在14.4 g/hm2的剂量下,0.8％阿维菌素微胶囊悬浮剂药后7 d的防效在89％以上,药后14 d防效仍超过80%,持效期为14 d左右。