Residues of cypermethrin,fenvalerate and deltamethrin on cauliflower

Following the application of Cypermethrin, fenvalerate and deltamethrin to a cauliflower crop at rates of 50, 50 and 12 g a.i. ha^-1, the maximum initial deposits of these insecticides on heads and leaves were 1.10 and 0.75, 1.14 and 0.60, and 0.32 and 0.12 mg kg^-1, respectively. These residue values for fenvalerate were less than the maximum residue limit (MRL) of 2 mg kg^-1 for this crop. While the maximum initial deposits of Cypermethrin and deltamethrin on cauliflower leaves were less than their respective MRL values of 1 and 0.2 mg kg^-1 for brassica leafy vegetables, it took one day for their residues on cauliflower heads to decline below this level.     

苏云金杆菌降低储粮害虫对磷化氢的抗药性

主要研究经过苏云金杆菌处理的米象对磷化氢、马拉硫磷、溴氰菊酯的敏感性。试验结果表明,抗磷化氢的米象品系经过苏云金杆菌处理7代后,对磷化氢的抗性有所降低;但经过苏云金杆菌处理的米象对马拉硫磷、溴氰菊酯却未表现负交互抗性。     

白僵菌油剂与溴氰菊酯混合超低量喷雾防治马尾松毛虫

对不同浓度白僵菌油剂与溴氰菊酯混合超低量喷雾防治马毛松毛虫的效果进行了研究。在每hm^2使用量为1500mL白僵菌油剂、1．5mL2.5％溴氰菊酯时，48h内的死亡率为28．1％；在用量为6000mL白僵菌油剂、12mL2．5％溴氰菊酯时，48h内的死亡率高达94．4％。到松毛虫化蛹时以上两处理的总体防治效果分别为48．8％和99．6％。各防区的白僵率从7．5％—31．5％不等。与白僵菌油剂的用量呈相关性。结果表明，白僵苗与溴氰菊酯混合的防治是快速而持续控制松毛虫的有效手段。     

溴氰菊酯对克氏原螯虾肌肉组织的毒性研究

为研究溴氰菊酯对克氏原螯虾的毒性效应及致毒机制,实验将克氏原螯虾成虾暴露于农药溴氰菊酯0.5、0.1和0.005μg/L三个浓度的药液中24h后,采用透射电镜观察克氏原螯虾肌肉组织超微结构损伤情况,并以细胞色素氧化酶活力(CCO)、乳酸脱氢酶活力(LDH)和乳酸(LD)含量为生物标志物评价溴氰菊酯对克氏原螯虾肌细胞呼吸产能功能的影响。结果显示,三个浓度的溴氰菊酯都会造成肌细胞超微机构不同程度的损伤,且浓度越大损伤越严重,损伤主要表现为肌原纤维断裂、肌浆网溶解,线粒体溶解。此外,三个浓度的溴氰菊酯都会对CCO活力、LDH活力和LD含量产生影响。其中0.1 μg/L的溴氰菊酯在6~24 h的暴露处理过程中会对肌肉的CCO活力产生极显著的抑制作用(P<0.01), LDH活力增强,乳酸含量上升。研究表明,0.5、0.1和0.005μg/L溴氰菊酯可以造成克氏原螯虾肌细胞超微结构损伤,激活细胞的厌氧呼吸,在组织中产生大量的乳酸,乳酸的蓄积会对造成细胞酸化而加重对细胞的毒性。     

近红外光谱法快速测定农药中溴氰菊酯含量

用近红外(NIR)光谱技术结合偏最小二乘法(PLS)进行了敌杀死乳油中有效成分溴氰菊酯含量的快速检测。通过比较敌杀死乳油与常用溶剂的近红外光谱,确定了乳油中使用的溶剂为二甲苯。在敌杀死乳油中加入二甲苯或溴氰菊酯原药来配制不同浓度的校正集,采用PLS建立了有效成分溴氰菊酯的分析模型,模型的决定系数R2、校正标准差(SEC)、交互验证参差均方根(RMSECV)值分别为0.999 9,0.013和0.022。结果表明:近红外光谱技术可以准确测定商品农药制剂中有效成分含量,方法简便、快速,适用于溴氰菊酯制剂的现场、在线分析。     

Michael Elliott's billion dollar crystals and other discoveries in insecticide chemistry

The crowning achievement for Michael Elliott came in 1973 when his most outstanding candidate insecticide from 25 years of research crystallized from hexane solution. The stereochemically pure crystalline compound was the most potent synthetic insecticide ever made until that time, and it was highly selective for insects compared with mammals. It was given the name deltamethrin. Sequential stereospecific crystallization to isolate the most potent epimer and base‐catalyzed racemization of the remaining less active isomer could be used to produce deltamethrin efficiently on a large scale; it became the billion dollar crystals. Elliott's discoveries at Rothamsted in England with Norman Janes and David Pulman of resmethrin, permethrin, cypermethrin and ultimately deltamethrin provided crop protection and malaria control for millions of people. Michael also laid the background for lipophilic amide, dithiane and other insecticides and nerve probes that are not involved in pyrethroid cross‐resistance. Some aspects of these investigations were best conducted at Berkeley, where Michael studied pyrethrins in 1969, synthetic pyrethroids in 1974 and alternative insecticides in 1986–1988. This review considers Michael's seminal discoveries in insecticide chemistry, with emphasis on his Berkeley years. Copyright © 2010 Society of Chemical Industry     

Autosomal inheritance of deltamethrin resistance in field populations of Triatoma infestans (Heteroptera: Reduviidae) from Argentina

BACKGROUND: Triatoma infestans (Klug) is the major Chagas disease vector in the Southern Cone area of South America, and its chemical control is based on the use of pyrethroid insecticides. Resistance to deltamethrin in Salta Province, Argentina, has been detected in field populations since 2002, causing the failure of vector control campaigns in this disease‐endemic area. The inheritance of deltamethrin resistance in T. infestans was evaluated through reciprocal crosses conducted between resistant and susceptible insects. RESULTS: The response of the reciprocally mated insects' progeny to deltamethrin was intermediate between the highly resistant and the susceptible parent colonies. Lack of significant differences between the LD₅₀ and resistance ratios of the reciprocally mated insects indicated no sex linkage on this trait. CONCLUSION: Bioassay results, in addition to degree of dominance calculations, suggest that the resistance to deltamethrin in T. infestans is controlled by semi‐dominant, autosomally inherited factors. Copyright © 2010 Society of Chemical Industry     

溴氰菊酯对马尾松林昆虫群落多样性的影响

１９９５年７月至１９９６年６月,在湘中丘陵区马尾松林内用溴氰菊酯进行喷药防治害虫试验结果表明,溴氰菊酯对林内昆虫群落的物种丰富度和多样性均有影响．其中植食类群受影响的主要是同翅目、直翅目、鳞翅目、鞘翅目和半翅目昆虫,捕食类群主要是蚂蚁和蜘蛛．在药剂作用下,植食类群和寄生类群的物种丰富度及多样性水平均呈现下降,捕食类群的物种丰富度虽有所下降,但在整个群落中所占的比例及多样性水平均有较大程度的上升．施用溴氰菊酯可降低植食物种的优势度,提高天敌类群与植食类群之比值,使昆虫群落在一定时间内保持相对稳定．但它降低了群落内物种的丰富度（特别是稀有种和偶见种）及多样性水平,因此在生产上用其防治松林害虫时不宜在大面积范围内长期使用．     

Insensitive Acetylcholine Receptor Conferring Resistance of Plutella xylostella to Nereistoxin Insecticides

The combinative rate measurement of （3-[I125] iodotyrosyl） α-bungarotoxin was applied in the analysis of the relation between nerve acetylcholine receptor and three types of insecticide resistance in diamondback moth, Plutella xylostella （L.）. In the dimehypo-resistant strain and in the cartap-resistant strain, the nerve acetylcholine receptor showed the remarkable insensitivity to dimehypo and cartap, of which the binding rate to ligand was approximately 66 and 60%, respectively, of the susceptible strain. The sensitivity to deltamethrin in the deltamethrin-resistant strain did not show visible change. These results indicated that the decline in the sensitivity of nerve acetylcholine receptor to insecticide might be a potential mechanism to nereistoxin insecticides resistance in the diamondback moth.