草地贪夜蛾对甲氨基阿维菌素苯甲酸盐和虱螨脲的抗性风险评估

甲氨基阿维菌素苯甲酸盐(甲维盐)和虱螨脲是目前生产上防治草地贪夜蛾的主要杀虫剂,为评估其抗性风险,以福建省草地贪夜蛾田间种群为研究对象,在实验室抗性汰选品系选育基础上,采用数量遗传学域性状分析法并结合交互抗性测定,进行草地贪夜蛾对上述两种杀虫剂的抗性风险评估。结果表明：非连续汰选11代和10代后,草地贪夜蛾对甲维盐(F₁₁)和虱螨脲(F₁₀)的抗性倍数分别达30.57倍和11.35倍;抗性现实遗传力分别为0.403和0.555,且前半段筛选的抗性遗传力都远大于后半段;药剂在室内对草地贪夜蛾致死率为50%～90%时,对甲维盐和虱螨脲抗性倍数上升10倍需要汰选8～15代和6～12代。交互抗性测定显示,甲维盐汰选品系对氯虫苯甲酰胺、虱螨脲、虫螨腈无交互抗性,对茚虫威和乙基多杀菌素存在一定交互抗性。虱螨脲汰选品系对氯虫苯甲酰胺、甲维盐、茚虫威、虫螨腈和乙基多杀菌素均无交互抗性。结果表明：草地贪夜蛾对甲维盐和虱螨脲存在快速产生抗性的风险,但可通过与无交互抗性药剂轮用来延缓抗性发展。     

阿维菌素和甲维盐对家蚕的毒性测定

本文测定了阿维菌素和甲氨基阿维菌素苯甲酸盐（简称＂甲维盐＂）4种杀虫剂制剂对家蚕的急性食下毒性和残毒期,结果表明：对3龄起蚕的LC50值分别为阿维菌素乳油7.2343×10-4mg/L,阿维菌素水乳剂7.6512×10-4mg/L,甲维盐微乳剂8.5940×10-4mg/L,甲维盐乳油14.0112×10-4mg/L。阿维菌素和甲维盐4种制剂的相同质量浓度（13.33 mg/L）稀释液喷洒桑树,在桑叶上的残毒期分别为3.2%阿维菌素乳油2400倍约为50 d,1.8%阿维菌素水乳剂1350倍、2.3%甲维盐乳油1725倍约为60 d,2.2%甲维盐微乳剂1650倍＞60 d;阿维菌素类4种制剂对家蚕的急性食下毒性极强,处理间差异较小,但在桑叶上的残毒期很长,处理间差异较大。     

Stability,cross-resistance and fitness costs of resistance to emamectin benzoate in a re-selected field population of the beet armyworm,Spodoptera exigua (Lepidoptera: Noctuidae)

Spodoptera exigua (Hübner) has a worldwide distribution with a high capacity for damaging a wide range of food, forage and fiber crops. It has been reported extensively from all over the world that populations of this pest species have developed field resistance against many insecticides. The objectives of this study were to determine whether an emamectin benzoate resistant field population of S. exigua re-selected with emamectin benzoate in the laboratory (Ema-SEL) showed cross-resistance to other insecticides, whether resistance was stable under laboratory conditions, and whether there were fitness costs associated with emamectin benzoate resistance. Bioassays at G₁ for the field population, gave resistance ratios (RRs) of 220, 149 and 38-fold for emamectin benzoate, spinosad and lufenuron, respectively, compared with a susceptible laboratory population (Lab-PK). Resistance ratios were increased by 526-fold and 6-fold compared with Lab-PK and the unselected field population (Ema-UNSEL, G₆), respectively after selection with emamectin benzoate (Ema-SEL) for five generations (G₆). Selection with emamectin benzoate had no apparent effect on susceptibility of Ema-SEL to spinosad and lufenuron, instead toxicity to the latter insecticides reduced, suggesting there was no cross-resistance between these compounds. Analysis of various life history traits suggested that the Ema-SEL population had a lower overall fitness (0.38) compared with the Lab-PK (1.0). Lack of cross-resistance and the apparent instability of resistance to emamectin benzoate suggest that spinosad and lufenuron are suitable alternatives for use with emamectin benzoate in resistance management. In addition, the high relative fitness costs observed suggests that emamectin benzoate-resistant insects are at a considerable disadvantage to susceptible populations in the absence of selection pressure although this remains to be tested under field conditions.     

EB+P4+阴道栓对荷斯坦青年牛超数排卵效果的影响

采用苯甲酸钠雌二醇(estradiolbenzoate,EB) 孕激素(progesterone,P4) 阴道栓方法对荷斯坦青年牛进行人工诱导卵泡波处理,比较不同剂量P4和不同阴道栓诱导新的卵泡波的发生,以及对同期发情效果和超排效果的影响。实验结果表明,海棉栓组PGF2α处理后到奶牛发情的时间间隔为48.3h,孕酮缓释阴道栓组为39h,两组差异极显著(P<0.05);海棉栓组的头均获胚数显著高于孕酮缓释阴道栓组(13.2和8.7枚,P<0.05),头均可用胚数显著高于孕酮缓释阴道栓组(5.7和3.3枚,P<0.05);外源注射50和100mgP4都能够成功地诱导新的卵泡波的发生,同期发情效果和超排效果没有显著差异(P>0.05)。     

甲维·毒死蜱高效液相色谱分析

介绍了以甲醇-乙腈-氨水溶液(体积比75︰10︰15)为流动相,使用HypersilODS不锈钢柱,在245nm条件下使用紫外检测器,对甲维.毒死蜱25%水乳剂进行高效液相色谱分离和测定,外标法定量。测定方法中各有效成分回收率分别为:甲氨基阿维菌素苯甲酸盐在99.06～100.00%范围内;毒死蜱99.83～100.04%,标准偏差:甲氨基阿维菌素苯甲酸盐为0.042;毒死蜱为0.095 0,变异系数:甲氨基阿维菌素苯甲酸盐为0.038%;毒死蜱为0.004%,线性相关系数:甲氨基阿维菌素苯甲酸盐为0.999 31;毒死蜱为0.999 72。该方法快速、准确、可靠。     

2%甲氨基阿维菌素苯甲酸盐微乳剂的高效液相色谱分析

采用高效液相色谱法对甲维盐微乳剂进行定量分析。结果表明,该方法的标准偏差为0.007;变异系数为0.35%;线性相关系数为0.999 9;平均回收率为99.99%;适用于2%甲维盐微乳剂的质量控制和产品检测。     

甲胺基阿维菌素苯甲酸盐与高效氯氰菊酯混配对甜菜夜蛾的增效作用

采用点滴法,测定了甲胺基阿维菌素苯甲酸盐与高效氯氰菊酯混配对甜菜夜蛾幼虫的增效作用。结果表明:甲胺基阿维菌素苯甲酸盐与高效氯氰菊酯以0.1∶3.9、0.2∶3.8、0.3∶3.7、0.4∶3.6、0.5∶3.5混配都表现出明显的增效作用,共毒系数(CTC)为256.2~757.1,其中以0.3∶3.7与0.4∶3.6混配增效作用最强,其共毒系数分别为753.4和757.1。     

5%甲维盐水分散粒剂防治鳞翅目害虫田间效果

【目的】评价5%甲氨基阿维菌素苯甲酸盐(甲维盐)水分散粒剂(WG)对鳞翅目害虫的田间防效。【方法】采用田间小区药效试验和五点取样法调查并计算供试药剂在甘蓝上对甜菜夜蛾和在水稻上对稻纵卷叶螟的田间防效。【结果】供试药剂5%甲维盐WG有效成分7.5、12.0、15.0 g/hm~2喷施后7 d对甜菜夜蛾的防治效果分别为82.87%、89.37%和91.02%,喷施后14 d对稻纵卷叶螟的防治效果分别为90.32%、94.20%和98.03%。差异显著性分析结果表明:供试药剂12.0 g/hm~2处理后7 d和14 d对甜菜夜蛾的防效显著高于对照药剂5.7%甲维盐乳油处理的防效;供试药剂12.0 g/hm~2 处理后14 d对稻纵卷叶螟的防效显著高于5.7%甲维盐乳油处理的防效。【结论】5%甲维盐WG对甜菜夜蛾和稻纵卷叶螟具有较好的防治效果,持效期较长,对农作物无药害,对有益生物无不良影响。     

适于草坪斜纹夜蛾防治的绿色农药室内筛选

为了筛选适于草坪害虫斜纹夜蛾（Prodenia litura）防治的绿色农药,采用浸叶法测定比较了5个不同化学类别共20种绿色杀虫剂对斜纹夜蛾3龄幼虫的室内活性。结果表明,7种常用农用拟除虫菊酯类杀虫剂的杀虫效果不及常规有机磷农药毒死蜱,而2种新型拟除虫菊酯四氟醚菊酯和四氟苯菊酯的杀虫效果相当或优于毒死蜱;苯甲酰脲类药剂虱螨脲、氟啶脲和氟铃脲,双酰肼类虫酰肼,杂环类茚虫威和虫螨腈,以及生物源类杀虫剂甲氨基阿维菌素苯甲酸盐7种药剂对斜纹夜蛾的活性高,均符合绿色无公害农药的基本要求,是值得进一步试验开发用于草坪斜纹夜蛾等夜蛾类害虫防治的候选药剂。