感染Bt的铜绿丽金龟幼虫对化学杀虫剂的敏感性变化及相关酶活性测定

采用Bt预处理和Bt与化学杀虫剂混用的方法,研究了感染Bt的铜绿丽金龟幼虫对辛硫磷、毒死蜱的敏感性变化及幼虫体内相关酶活性的变化.结果表明,随着Bt预处理时间和感染剂量的增加,铜绿丽金龟幼虫对化学杀虫剂敏感性显著增强,20μg/g的Bt预处理3和5d后,对辛硫磷和毒死蜱的敏感性分别提高1.96、3.28倍和6.71、16.14倍;80μg/g预处理对辛硫磷和毒死蜱的敏感性分别提高了10.22、27.10倍和13.03、51.33倍.Bt与化学杀虫剂混用后,该幼虫对两种化学杀虫剂的敏感性也有大幅度提高,Bt分别以1：50和1：200与杀虫剂混用时,铜绿丽金龟幼虫对辛硫磷和毒死蜱敏感性分别提高6.06、4.00倍和16.05、12.78倍.经Bt预处理后,金龟子幼虫体内的乙酰胆碱酯酶的比活力与对照相比略有降低,谷胱甘肽-S-转移酶和羧酸酯酶的比活力均有不同程度的升高.     

灭幼脲对韭菜迟眼蕈蚊的活性及其应用技术研究

作者测定了灭幼脲对韭菜迟眼蕈蚊Bradysia adoriphaga Yang et Zhang 不同龄期幼虫及预蛹和蛹毒力，结果表明：低龄幼虫对灭幼脲最敏感，随着龄期的增加敏感性降低，4龄幼虫的LC50是2龄幼虫的2．13倍，预蛹对灭幼脲的敏感性强，蛹对灭幼脲的敏感性低，田间试验结果表明：20％灭幼脲悬浮剂667^m2用量600—800mL加水灌根，可较好地控制该虫危害，且持效期可长达90d。明显优于常规农药辛硫磷和乐斯本的防治效果。     

Long-term foliar persistence and efficacy of spinosad against beet armyworm under greenhouse conditions

BACKGROUND: The immediate lethality caused by spinosad has been widely studied on Spodoptera exigua (Hübner). However, long‐term effects can also provide valuable information on insecticide toxic action. Here, the persistence of spinosad on Capsicum annuum L. foliage and the lethal and sublethal effects of greenhouse‐aged foliar residues of this insecticide on third instars of S. exigua are reported. RESULTS: Foliage was collected at 0, 3, 5, 10, 20, 30, 40 and 50 days after application, and spinosad residues were measured. Residues decreased over time according to first‐order kinetics. The average rate constant and half‐life of disappearance were 4.44 × 10^?3 and 156 days and 5.80 × 10^?3 and 120 days for 60 and 120 mg L^?1 respectively. Larval mortality gradually decreased, corresponding to the residues, but was still appreciable (35 and 65% for 60 and 120 mg L^?1 respectively) when the larvae were fed with foliage collected 50 days after treatment. Subsequently, pupal development was reduced and varied between 20 and 60% and between 21 and 41% for 60 and 120 mg L^?1, respectively, in all ages of leaf residues that were bioassayed. At all time points, the consumption rate by the larvae was reduced between 62 and 84% for both concentrations that were bioassayed. CONCLUSION: It is concluded that, under the present greenhouse conditions, the degradation of spinosad was slower than that reported by other authors in the field, and, because of that, its residues could cause lethal and sublethal effects to S. exigua larvae. Copyright © 2011 Society of Chemical Industry     

炔类化合物对亚洲玉米螟拒食活性和电生理反应

利用饲料柱法测定了人工合成的 9个共轭二炔和 3个单炔类化合物对亚洲玉米螟 Ostrinia furnacalis(Guene'e) 5龄幼虫的拒食活性 ,并利用顶端记录技术 ,诱发该虫栓锥感受器感受细胞的电位脉冲反应。结果表明 :受试的炔类化合物对亚洲玉米螟幼虫具有不同程度的拒食活性 ,特别是化合物 2 (6,6-二甲基-2,4-庚二炔-1-醇、化合物 3(2,4-己二炔-1,6-二醇 )、化合物 9(1-苯基-2 ,4-己二炔 )和化合物 11(3-溴-2-丙炔-1-醇 ) ,实验剂量为 500μg/g饲料时 ,2 4 h非选择性拒食率在 80%左右。电生理测定结果表明 :浓度为 1mg/mL时 ,该系列化合物刺激中栓锥感受器能诱发感受细胞发放不同频率的脉冲和振幅 ,脉冲频率在 8.30～31.00imp/s,振幅在 400～1000μV之间。刺激侧栓锥感受器 ,也能诱发感受细胞发放不同频率的脉冲 ,脉冲频率在 6.00～ 15.66imp/s之间。将化合物诱发中栓锥感受细胞电位脉冲频率与生测拒食活性进行比较 ,发现二者存在一定程度的相关性。在剂量 -发放频率测试中 ,测得化合物 9诱发栓锥感受器脉冲频率具有浓度依赖性。     

马铃薯块茎蛾幼虫致病黏质沙雷氏菌的分离鉴定及杀虫活性

从马铃薯田自然罹病马铃薯块茎蛾幼虫上,分离到1株对马铃薯块茎蛾幼虫具有较强致病作用的菌株ML-1,通过形态及16S rRNA序列测定分析,确定该菌株ML-1为黏质沙雷氏菌Serratia marcescens。采用饲喂法分别测定了该菌株ML-1菌悬液、发酵液及发酵上清液对马铃薯块茎蛾初孵3日龄幼虫的毒力。结果表明,用ML-1菌悬液、发酵液及发酵上清液饲喂后第7 d时,马铃薯块茎蛾3日龄幼虫的累积校正死亡率分别为63.16%、80.70%和49.12%,在3.0×10⁹ cfu/mL浓度下的LT₅₀分别为4.71、3.04和6.47 d,在发酵液处理后第3、5和7 d的LC₅₀分别为9.784×10¹⁰、1.855×10⁸和5.434×10⁵ cfu/mL。综上所述,黏质沙雷氏菌ML-1菌株对马铃薯块茎蛾幼虫有较强的毒力,在马铃薯块茎蛾绿色防控中具有一定的开发潜能。     

Impact of sub-lethal residues of azinphos-methyl on the pheromone-communication systems of insecticide-susceptible and insecticide-resistant obliquebanded leafrollers Choristoneura rosaceana (Lepidoptera: Tortricidae)

The effects of sub-lethal residues of azinphos-methyl on pheromone production, calling, female attractiveness and the ability of males to locate sources of natural and synthetic pheromone were compared in azinphos-methyl-susceptible (susceptible) and azinphos-methyl-resistant (resistant) obliquebanded leafrollers, Choristoneura rosaceana (Harris). The amount of pheromone in susceptible females was reduced by 29-33% after exposure to azinphos-methyl; this treatment did not affect the pheromone content of resistant females. Azinphos-methyl-treated resistant females contained 39-43% less pheromone than azinphos-methyl-treated susceptible females. Resistant females that were not treated with azinphos-methyl contained 35-56% less pheromone than susceptible females that were not treated with insecticide. The incidence of calling was reduced by 67-100% in azinphos-methyl-treated susceptible females; the incidence of calling by resistant females was not affected by exposure to azinphos-methyl. The incidence of calling by azinphos-methyl-treated susceptible females was 58-100% lower than that of azinphos-methyl-treated resistant females. There was no difference in the incidence of calling between susceptible and resistant females that had not been treated with insecticide. In a flight tunnel, treatment with insecticide reduced the attractiveness of susceptible females by 38%; treatment with insecticide did not affect the attractiveness of resistant females. There was no difference in the proportion of males attracted to susceptible and resistant females that had, or had not been treated with insecticide. In an apple orchard, the attractiveness of susceptible and resistant females treated with azinphos-methyl was reduced by 84 and 12%, respectively. The proportion of males attracted to azinphos-methyl-treated susceptible females was 58% lower than the proportion attracted to azinphos-methyl-treated resistant females, whereas, if females were not treated with insecticide, the proportion attracted to resistant females was 57% lower than the proportion attracted to susceptible females. In a flight tunnel, azinphos-methyl did not affect the ability of susceptible or resistant males to locate a source of pheromone gland extract. Likewise, in an apple orchard, the insecticide treatment had no effect on the ability of susceptible or resistant males to locate a source of synthetic pheromone. In a flight tunnel, there was no difference in the proportion of azinphos-methyl-treated susceptible and resistant males locating a source of pheromone gland extract; however, in the orchard, 39% fewer azinphos-methyl-treated resistant males located a source of synthetic pheromone than azinphos-methyl-treated susceptible males. A similar proportion of susceptible and resistant males that had not been treated with insecticide located a source of pheromone gland extract in the flight tunnel, but in the orchard, the proportion of resistant males not treated with azinphos-methyl that located the source of synthetic pheromone was 32% lower than the proportion of susceptible males not treated with this insecticide. The implications of the differences in the effect of sub-lethal residues of azinphos-methyl on the pheromone communication system of susceptible and resistant moths are discussed in relation to the theory of the development of insecticide resistance, the detection of resistance in feral populations of moths using sex pheromone-baited traps, and the control of moths using sex pheromone-mediated mating disruption.     

The Synthesis and Insecticidal Activity of a Series of 2-Aryl-1,2,3-triazoles

Two synthetic routes to 2-aryl-1,2,3-triazoles are outlined. These have been used to synthesise a wide range of compounds of this structural type. Their insecticidal activities were evaluated against a number of veterinary and public health pests. The activity of these compounds is especially good against the housefly (Musca domestica). Structure–activity relationships are discussed particularly in relation to the physical properties of the compounds.     

表皮碳氢化合物在云杉大墨天牛和云杉小墨天牛鉴定中的应用

云杉大墨天牛和云杉小墨天牛是进境木材及木质包装中常见的检疫性害虫,由于墨天牛属近缘种之间的幼虫形态相似,形态鉴定资料不完整,对低龄幼虫的鉴定尤其困难。为了鉴定云杉大墨天牛和云杉小墨天牛,本文利用气相色谱-质谱联用仪(GC-MS)对云杉大墨天牛和云杉小墨天牛幼虫的表皮碳氢化合物进行了分析,经NIST数据库检索,并与标准图谱比较,应用色谱峰面积归一法测定各组分及其相对含量。结果表明,云杉大墨天牛和云杉小墨天牛幼虫表皮中的主要碳氢化合物由C24~C44的直链或支链、饱和及不饱和的长链烃类组成。云杉大墨天牛幼虫表皮有9种碳氢化合物,而云杉小墨天牛幼虫表皮有8种碳氢化合物,其中6种碳氢化合物为两种昆虫共有,但在含量上有差异。云杉大墨天牛特有的成分为正二十四烷、正三十六烷、正四十四烷,而云杉小墨天牛特有的成分为2-甲基-二十六烷、9-二十六碳烯。这些特有表皮碳氢化合物可用于近缘种云杉大墨天牛和云杉小墨天牛的分类鉴定。     

N'-硝基缩氨基胍类化合物对蚜虫的室内毒力测定及相关酶活性的影响

Su50[N'-硝基-1-异丙基-2-(4-硝基苯亚甲基)氨基胍]和Su56(N'-硝基-1-烯丙基-2-正丙基氨基胍)是利用活性亚结构拼接原理合成的具有新烟碱类和缩氨基脲类杀虫剂共同结构特征的硝基缩氨基胍类化合物。为了解Su50和Su56对蚜虫的生物活性及作用机理,采用叶片浸渍法测定了其对多种蚜虫的杀虫活性,用棉叶涂抹药液后接入棉蚜Aphis gossypii Glover测定了其对棉蚜的拒食活性,并采用生化方法测定了不同亚致死浓度(LC_(10)、LC_(25))Su56对棉蚜羧酸酯酶(CarE)、乙酰胆碱酯酶(AChE)、谷胱甘肽S-转移酶(GSTs)和多功能氧化酶(MFO)的酶活性的影响。结果表明:Su50和Su56对棉蚜A.gossypii/桃蚜Myzus persicae Sulzer,苹果黄蚜Aphis citricola van der Goot和梅大尾蚜Hyalopterus amygdali Blanchard均具有一定的杀虫活性,但毒力差异不显著,其中Su50对棉蚜、桃蚜、梅大尾蚜和苹果黄蚜的LC_(50)值分别为13.0、24.2、62.6和14.3mg/L,Su56的LC_(50)值则分别为30.3、30.2、101和3.23 mg/L;同时Su50和Su56对供试棉蚜均具有一定的拒食活性。生化试验结果表明,Su56在LC_(10)和LC_(25)浓度下对棉蚜的CarE、GSTs和MFO酶活性无显著影响,但在LC_(10)浓度下对棉蚜的ACNE酶活性却有显著抑制作用。     

纳他霉素对冬枣浆胞病菌的毒力及保鲜生理效应研究

研究了不同浓度纳他霉素对冬枣浆胞病菌Alternaria Nees ex Wallr.的室内毒力以及对冬枣低温贮藏期间生理生化指标的影响。结果表明,纳他霉素对冬枣浆胞病菌的EC50和EC90值分别为39.56和208.48 mg/L,与对照药剂咪鲜胺、异菌脲相比,EC90值无显著差异;经500~1 000 mg/L 的纳他霉素处理可显著抑制冬枣丙二醛(MDA)含量的增加,并使多聚半乳糖醛酸酶(PG)与苯丙氨酸解氨酶(PAL)的活性提高,对保持果实硬度有很好的效果,并且抑制了可溶性固形物、抗坏血酸(Vc)含量的下降。经1 000 mg/L纳他霉素处理的冬枣贮藏到60 d其商品率达87.3%,高于对照组的商品率(72.9%);贮藏到100 d其商品率仍可达到75.0%,显著高于对照组(50.2％)。