阿维菌素对南方小花蝽的毒杀作用

在室内条件下,研究了阿维菌素两种产品对南方小花蝽的毒杀效果。结果表明,两种产品对南方小花蝽不同虫态均有一定的毒杀作用。成虫、若虫对阿维菌素的敏感性基本相同,而卵的敏感性最低。阿维菌素对南方小花蝽除有直接的毒杀作用外,对其捕食能力也有一定影响。     

阿维菌素和阿维·吡虫啉对马铃薯桃蚜的亚致死效应

为了明确阿维菌素和阿维·吡虫啉不同亚致死剂量对马铃薯桃蚜F₀代成蚜和F₁代的干扰作用。通过在室内组建不同亚致死剂量下马铃薯桃蚜生命表的方法,分析了不同亚致死剂量对马铃薯桃蚜繁殖、发育和种群参数的影响。结果表明：用阿维菌素和阿维·吡虫啉LC₁₀、LC₂₅、LC₄₀分别处理马铃薯桃蚜成蚜后,成蚜的平均产蚜量显著小于对照,其平均寿命也显著短于对照。其中阿维·吡虫啉LC₄₀组的平均产蚜量最低,为9.52头,平均寿命最短,为8.07天。与对照组相比,F₁代的若蚜期显著延长,成蚜期显著缩短。对F₁代种群参数的影响体现在,净增殖率(R_o)、内禀增长率(r_m)以及周限增长率(λ)都显著降低,种群加倍时间(D_t)显著延长。即阿维菌素和阿维·吡虫啉不同亚致死剂量处理亲代成蚜后,会明显抑制其寿命和产蚜量,同时也可以有效控制F₁代种群再猖獗。     

Avermectin exposure induces apoptosis in King pigeon brain neurons

The effect of avermectin was studied on King pigeon brain nerve cells by cytotoxicity [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide, MTT] and apoptosis [acridine orange/ethidium bromide (AO/EB) assay, transmission electron microscope (TEM) evaluation, measurement of mitochondrial membrane potential (Δψm), phosphatidylserine (PS) exposure, caspases activities, DNA fragmentation, reactive oxygen species (ROS) and caspase-3 mRNA expression] within the 2.5–10 μg L⁻¹ concentration-range. The results revealed that within the concentrations of 2.5–10 μg L⁻¹, avermectin showed obvious cytotoxicity and induced apoptosis in a dose-dependent manner to neurons of King pigeon in vitro. Cell viability were 99.93 ± 8.52%, 82.02 ± 4.99% and 78.23 ± 5.67% after 24 h of treatment with avermectin at the concentrations of 0, 2.5 and 5 μg L⁻¹, which decreased to 56.36 ± 2.17% of 10 μg L⁻¹. Treated cells showed typical apoptosis morphological changes including cytoplasmic vacuolation, chromatin condensation, unclear nuclear membrane and decreased/swollen mitochondria. Typical biochemical hallmarks of apoptosis including Δψm loss, PS exposure, activations of caspase-3, caspase-8 and caspase-9, DNA fragmentation were observed too. Moreover, the levels of ROS in the avermectin treatment groups increased significantly compared to control group. Furthermore, the caspase-3 mRNA levels increased significantly following AVM treatment. In conclusion, our experimental results show that avermectin has cytotoxicity to brain neurons of King pigeon in vitro and the mechanism of neurotoxicity induced by avermectin is closely related to apoptosis.     

应用叶片保护率评价阿维菌素对小菜蛾的毒力

采用叶片保护率评价阿维菌素对小菜蛾(Plutella xylostella(Linnaeus))2龄、3龄幼虫的毒力.以期为该药毒力的准确评价提供资料.浸叶法测定阿维菌素对小菜蛾2龄、3龄幼虫室内毒力的同时,观察记录24 h、48 h、72 h校正死亡率、叶片保护率.对小菜蛾2龄幼虫,24 h、48 h、72 h的LC50分别为>10.00 mg/L、2.87 mg/L、0.56 mg/L;相同时间内PC50分别为0.25 mg/L、0.82 mg/L、1.43 mg/L.对3龄幼虫,24 h、48 h、72 h的LC50分别为>10.00 mg/L、6.20 mg/L、3.00 mg/L;相同时间内PC50分别为<0.16mg/L、0.04mg/L、4.25 mg/L.根据叶片保护率,可以发现阿维菌素对小菜蛾影响快,但是当阿维菌素毒力达到稳定时,必须有较高的校正死亡率,否则达不到理想的叶面保护效果.     

不同剂型阿维菌素理化性能及对小菜蛾活性的评价

研制了阿维菌素微乳剂和水乳剂配方，并在室内和田间测定了阿维菌素不同剂型对小菜蛾幼虫的生物活性．结果表明：微乳剂和水乳剂的表面张力、渗透时间、润湿时间等测定值均优于乳油，微乳剂是其中表现最稳定的水性化剂型．毒力测定表明阿维菌素与杀虫双复配剂的增效比值最高．当对照剂型乳油LC50设为1时，其毒力比值达3．24．田间施药后，阿维菌素和杀虫双复配剂对小菜蛾的防效最好，药后7d防效达89．12％，均明显高于阿维菌素单剂，3个单剂处理间差异显著．     

单剂量口灌阿维菌素在草鱼体内的药动学及残留研究

按0.1 mg/kg的剂量给草鱼(Ctenopharyngodon idellus)灌服阿维菌素,用高效液相色谱法检测用药后不同时间的血浆、肌肉和肝脏中的药物浓度,然后用3P97药代动力学软件处理药时数据,对药物在草鱼体内药动学及组织残留进行研究.结果表明:单剂量口灌阿维菌素在草鱼血浆中主要药动学参数为:AUC 1 6...