啶虫脒和阿维菌素在4种不同类型土壤中的吸附及迁移

采用薄层层析和平衡振荡法,分别测定了啶虫脒和阿维菌素在紫色土、砖红土、黄壤土和黑土4种不同类型土壤中的迁移率(Rf )和吸附常数(Kd),比较了2种农药在单用及混用下迁移和吸附行为的差异。结果表明:2种农药在单用及混用下的迁移行为几乎不存在差异,在4种土壤中的Rf 值大小顺序均为:黄壤土>紫色土>黑土>砖红土;2种农药的吸附过程均符合经典的Freundlich模型,混用时阿维菌素对啶虫脒的吸附无影响,但啶虫脒的存在会减少土壤对阿维菌素的吸附,表现为竞争吸附作用。     

Longevity of a mixture of acetamiprid and bifenthrin (Transport(TM) ) at the termiticidal application rate

BACKGROUND: The 30 month longevity, mobility and insecticidal activity of a combination of acetamiprid and bifenthrin currently marketed in the United States for the prevention of termite infestation in buildings was investigated in greenhouse and laboratory studies. RESULTS: Acetamiprid dissipated to below the limit of detection within 7 months of application, while bifenthrin remained in the soil at levels sufficient to kill termites for the duration of the study. Acetamiprid was detected in decreasing amounts in eluates of treated soil from months 1 to 4, while no bifenthrin was detected in eluates at any time. The treated soil remained toxic to termites for the 30 month duration of the study. Two indices of synergy between technical‐grade acetamiprid and bifenthrin demonstrated that it is unlikely that there would be any synergism between the two active ingredients in the field. The presence of vegetation did not have a significant effect on the longevity of bifenthrin, except at intermediate times, where residues in the treated soil were higher in vegetated plots, depending on depth and time. CONCLUSIONS: Acetamiprid has a short residual time in soil, and this formulation's effectiveness beyond about 7 months against subterranean termites is due to the bifenthrin content. Copyright © 2011 Society of Chemical Industry     

Rapid report acetamiprid resistance and cross-resistance in the diamondback moth, Plutella xylostella

A 110-fold acetamiprid-resistant Plutella xylostella (L) strain was established after four selection experiments (in five generations) on a 9.5-fold resistant colony in the laboratory. The resistant strain did not show cross-resistance to chlorfluazuron or Bacillus thuringiensis subsp kurstaki Berliner, but displayed low resistance to cartap and phenthoate.     

露地和大棚条件下啶虫脒在黄瓜和土壤中的残留及消解动态

采用乙腈提取、固相萃取净化和高效液相色谱法,分析测定了啶虫脒在露地和大棚2种种植条件下黄瓜和土壤中的残留及消解动态。结果表明:9%啶虫脒可湿性粉剂同时在露地和大棚中按有效成分30.375 g/hm2剂量(推荐高剂量的1.5倍)施药1次,啶虫脒在露地和大棚黄瓜及其土壤中的原始沉积量分别为0.20、0.13 mg/kg和0.29、0.14 mg/kg,露地黄瓜和土壤中的原始沉积量均分别低于大棚;相应地,啶虫脒在黄瓜和土壤中的半衰期分别为9.7、9.4 d(露地)和10.1、11.9 d(大棚)。9%啶虫脒可湿性粉剂同时在露地和大棚中按有效成分20.25 g/hm2和30.375 g/hm2的剂量施药1次和2次,在相同施药剂量、施药次数和采收间隔期情况下,除个别情况外,露地黄瓜中啶虫脒的最终残留量均低于大棚,分别为0.01~0.05 mg/kg(露地)和0.01~0.09 mg/kg(大棚)。     

啶虫脒亚致死剂量对豌豆蚜生长发育和繁殖的影响

在室内毒力测定的基础上,采用离体叶片饲养法,研究了啶虫脒亚致死剂量(LC₂₅、LC₁₅、LC_5)对豌豆蚜生长发育和繁殖的影响。发现啶虫脒对豌豆蚜的致死中浓度LC₅₀为2.751 mg/L。不同亚致死剂量对豌豆蚜的生长发育和繁殖也均有显著影响。经不同亚致死剂量处理后,豌豆蚜若蚜发育历期明显延长,而成蚜期、成蚜产蚜天数、平均产蚜量和日平均产蚜量与对照相比明显缩短或降低,亚致死剂量越大差异越明显。表明了啶虫脒亚致死剂量对豌豆蚜生长发育和繁殖均具抑制作用。     

Synergism and stability of acetamiprid resistance in a laboratory colony of Plutella xylostella

The involvement of metabolic enzymes in the resistance of a laboratory colony of diamondback moth, Plutella xylostella (L), to the neonicotinoid insecticide acetamiprid was determined with the synergists piperonyl butoxide (PBO), which suppresses the activity of cytochrome P-450 monooxygenases, and S,S,S-tributyl phosphorotrithioate (DEF), an inhibitor of esterases, using the leaf-dipping method. Both PBO and DEF enhanced the insecticidal activity of acetamiprid significantly in the resistant P. xylostella strain but not in a reference strain, suggesting that cytochrome P-450 monooxygenases and esterases play an important role in the resistance of P. xylostella to acetamiprid. The resistant P. xylostella strain was also reared without further exposure to acetamiprid to determine the stability of resistance. Maintaining the resistant strain for seven generations in the absence of selection pressure resulted in a drop in resistance ratio from 110 to 2.42, indicating that acetamiprid resistance in P. xylostella is not stable.     

Biological characterization of sulfoxaflor, a novel insecticide

BACKGROUND: The commercialization of new insecticides is important for ensuring that multiple effective product choices are available. In particular, new insecticides that exhibit high potency and lack insecticidal cross‐resistance are particularly useful in insecticide resistance management (IRM) programs. Sulfoxaflor possesses these characteristics and is the first compound under development from the novel sulfoxamine class of insecticides. RESULTS: In the laboratory, sulfoxaflor demonstrated high levels of insecticidal potency against a broad range of sap‐feeding insect species. The potency of sulfoxaflor was comparable with that of commercial products, including neonicotinoids, for the control of a wide range of aphids, whiteflies (Homoptera) and true bugs (Heteroptera). Sulfoxaflor performed equally well in the laboratory against both insecticide‐susceptible and insecticide‐resistant populations of sweetpotato whitefly, Bemisia tabaci Gennadius, and brown planthopper, Nilaparvata lugens (Stål), including populations resistant to the neonicotinoid insecticide imidacloprid. These laboratory efficacy trends were confirmed in field trials from multiple geographies and crops, and in populations of insects with histories of repeated exposure to insecticides. In particular, a sulfoxaflor use rate of 25 g ha^?1 against cotton aphid (Aphis gossypii Glover) outperformed acetamiprid (25 g ha^?1) and dicrotophos (560 g ha^?1). Sulfoxaflor (50 g ha^?1) provided a control of sweetpotato whitefly equivalent to that of acetamiprid (75 g ha^?1) and imidacloprid (50 g ha^?1) and better than that of thiamethoxam (50 g ha^?1). CONCLUSION: The novel chemistry of sulfoxaflor, its unique biological spectrum of activity and its lack of cross‐resistance highlight the potential of sulfoxaflor as an important new tool for the control of sap‐feeding insect pests. Copyright © 2010 Society of Chemical Industry     

啶虫脒金标免疫速测试纸条研制及其在茶叶中的应用

阐述了一种基于直接竞争免疫层析法的啶虫脒金标速测试纸条的研制方法,及其在茶叶中快速检测与诊断啶虫脒残留的应用情况。通过制备啶虫脒人工抗原,获得了高灵敏度的单克隆抗体,抗体效价大于1:10000。据此研制的金标速测试纸条对啶虫脒肉眼判断的检出限为10ng/mL,检测时间为10min;可特异性地检测茶叶(绿茶、红茶、铁观音)中烟碱类农药啶虫脒的残留量,而对其他烟碱类农药(吡虫啉、噻虫嗪、烯啶虫胺等)无交叉反应,能满足中国茶叶中啶虫脒最大残留限量(0.5mg/kg)下的检测要求,具有灵敏度高、使用便捷、结果准确、成本低等优点。该技术可以实现成品茶样品中啶虫脒的现场快速测试诊断。     

Benzpyrimoxan: Design,synthesis, and biological activity of a novel insecticide

Benzpyrimoxan (5-(1,3-dioxan-2-yl)-4-{[4-(trifluoromethyl)phenyl]methoxy}pyrimidine, NNI-1501) was discovered as a novel insecticide structurally characterized by a pyrimidine derivative substituted with 1,3-dioxanyl and 4-trifluoromethylbenzyloxy groups. The compound showed remarkable activity against nymphs of rice planthoppers, including strains resistant to existing insecticides. Furthermore, benzpyrimoxan had low adverse effects on pollinators and beneficial arthropods. Because of these features, benzpyrimoxan is expected to be a suitable part of an integrated pest management strategy. In this report, the history of the discovery to reach benzpyrimoxan and details of the structure–activity relationships are described.     

防治蚜虫、白粉虱的新颖杀虫剂-吡蚜酮(pymetrozine)

嗪酮类杀虫剂可分为二嗪酮类和三嗪酮类杀虫剂,因其具有高效、低毒、作用机制独特等特点而在农药研究领域具有重要的地位,其中吡蚜酮是此类杀虫剂中的典型代表。本文综述了吡蚜酮的开发历程和作用机制,以及二嗪酮类和三嗪酮类杀虫剂的研究进展,对该类杀虫剂的构效关系进行了总结,对其发展前景进行了展望。     

Flonicamid, a novel insecticide with a rapid inhibitory effect on aphid feeding

Flonicamid (IKI220; N-cyanomethyl-4-trifluoromethylnicotinamide), a pyridinecarboxamide compound, is a novel systemic insecticide with selective activity against hemipterous pests, such as aphids and whiteflies, and thysanopterous pests. The purpose of this study is to clarify the biological properties of flonicamid against aphids. Flonicamid is very active against aphids, regardless of differences in species, stages and morphs. This compound inhibited the feeding behaviour of aphids within 0.5 h of treatment without noticeable poisoning symptoms such as convulsion, and this antifeeding activity was not recoverable until death. The nymphs born from adults exposed to flonicamid for 3 h showed high mortality. The effect of flonicamid on the feeding activity of an individual aphid was studied using electronic monitoring of insect feeding behaviour (EMIF). Although the treated aphid attached the head of its proboscis to the leaf surface, salivation and sap feeding were strongly inhibited. These results suggest that the main insecticidal mechanism of flonicamid is starvation based on the inhibition of stylet penetration to plant tissues.     

A novel photodegradable insecticide: Preparation, characterization and properties evaluation of nano-Imidacloprid

Imidacloprid (IMI) microcrystals were directly encapsulated with nature polysaccharides chitosan (CHI) and sodium alginate (ALG) through layer-by-layer (LbL) self-assembly. The coated colloids were characterized using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The in vitro controlled release pattern of IMI through the PE diffusion barrier was studied using a diffusion cell assembly at physiological pH of 7.4. Photocatalysts were characterized by Brunauer-Emmett-Teller (BET) surface area and SEM. The adsorption and photocatalytic activities of photocatalysts were evaluated by isothermal adsorption and IMI degradation under UV light and natural light illumination. The toxicity of the photodegradable insecticide was evaluated against the adult stage of Martianus dermestoides. The results showed that thermodynamically stable IMI microcrystals were obtained by association and had a mean length of 7 μm and a ζ-potential of −37.5. The drug loading and encapsulation efficiency were 56.15 ± 0.96% and 81.57 ± 0.96%, respectively. The polysaccharide capsules prolonged the release time of the encapsulated IMI crystals. Among the photocatalysts, SDS/Ag/TiO₂ had the highest photocatalytic activity. Toxicity of the novel 50% nano-SDS/Ag/TiO₂-IMI was higher in the adult stage compared to the 95% IMI as indicated by the lower LC₅₀ value.     

季铵盐和有机硅助剂对啶虫脒杀虫活性及水生生物毒性的影响

分别以浸渍法和相加指数法,评价了5种季铵盐助剂和3种有机硅助剂分别与啶虫脒混合使用时对苹果黄蚜Aphis citricola的联合作用,以及对两种非靶标水生环境生物大型溞Daphnia magna和斑马鱼Brachydonio rerio的毒性。结果表明,有机硅助剂和季铵盐助剂对啶虫脒防治蚜虫具有明显的增效作用,且silwet 618的增效倍数高达210.2。环境毒性试验结果表明:啶虫脒对两种水生生物均为低毒;供试季铵盐和有机硅助剂对大型溞的单一毒性均为剧毒,季铵盐助剂对斑马鱼为高毒,而有机硅助剂对斑马鱼为中毒。与农药联合作用测定结果表明:有机硅助剂对两种水生生物均表现为增毒作用;而5种季铵盐助剂除十四烷基二甲基苄基氯化铵（1427）对大型溞表现为增毒作用外,其他4种对两种水生生物均呈现不同程度的拮抗作用。此外,季铵盐和有机硅助剂还可以显著降低清水的表面张力（由清水的74.37 mN/m降为20.50~40.07 mN/m）,提高叶片上的最大持留量（由清水的1.54 μg/cm2提高到2.39~4.34 μg/cm2）。因此,使用季铵盐和有机硅助剂作为增效剂时应考虑其对水生生物的毒性,其中季铵盐助剂对环境生物的潜在威胁更小。     

Effects of cycloxaprid,a novel cis‐nitromethylene neonicotinoid insecticide,on the feeding behaviour of Sitobion avenae

BACKGROUND: Cycloxaprid with cis‐configuration is a novel neonicotinoid insecticide, developed in China, that has good industrialisation prospects for its high activity against imidacloprid‐resistant pests. Studies were carried out to investigate the biological activity of cycloxaprid and its effect on the feeding behaviour of Sitobion avenae. RESULTS: The results demonstrated that cycloxaprid had good contact and root‐systemic activity. The electrical penetration graph (EPG) revealed that cycloxaprid significantly increased the total time of non‐probing periods and greatly inhibited phloem ingestion of treated aphids because it significantly reduced the total time and the frequency of phloem ingestion. Furthermore, cycloxaprid can increase the phloem salivation of treated aphids by comparison with aphids treated with imdacloprid and distilled water. Consequently, a sublethal dose of cycloxaprid impaired aphid ingestion of phloem sap and thereby reduced the weight of aphids. On the other hand, EPG data showed that a sublethal dose of cycloxaprid had no significant effect on xylem sap ingestion, in contrast to imidacloprid. CONCLUSION: All these tests indicated that cycloxaprid had both contact and root‐systemic activity, with sublethal effects resulting in reduction in Sitobion avenae phloem‐feeding behaviour and growth rate. Copyright © 2012 Society of Chemical Industry     

啶虫脒在小麦及土壤中残留行为研究

利用气相色谱外标法定量分析检测3%啶虫脒乳油在小麦和麦田土壤中的消解动态以及残留量,为制定啶虫脒在小麦上的合理使用提供科学依据。检测结果表明,啶虫脒在小麦植株和土壤中的半衰期分别为5.3~5.8d和7.1~7.8d。啶虫脒在距离最后施药14d采样时麦秸中的残留量为0.030 5~0.182 2mg/kg,土壤中残留量为0.009 1~0.026 1 mg/kg,麦粒中残留量0.002 7~0.072 5mg/kg。     

Identification of a novel trait associated with phytotoxicity of an insecticide etofenprox in soybean

Synthetic insecticides are widely used to control pests in various crop fields. Especially in soybean [Glycine max (L.) Merr.] fields, the insecticide etofenprox, which is a pyrethroid derivative, has been used to manage hemiptera pests. To date, soybean phytotoxicity response has not been reported to etofenprox derivatives, two Korean cultivars, Danbaek and Kwangan, were first identified to show leaf shape shrinkage damage after etofenprox application. We confirmed that the causal substance for phytotoxicity is etofenprox and that it had dosage effects. Through genetic analysis using three F₂ populations, sensitivity to etofenprox is confirmed to be managed by a single dominant gene, and that gene is the same in Danbaek and Kwangan. Although further genetic research is required to identify the gene responsible for sensitivity to etofenprox, the results of this study will help to elucidate the interaction between plants and chemicals when breeding new cultivars or developing pesticides.     

Lethal and sub-lethal effects of a novel sulfoximine insecticide,sulfoxaflor, against Asian citrus psyllid and its primary parasitoid under laboratory and field conditions

The Asian citrus psyllid, Diaphorina citri Kuwayama, is the most important international pest of citrus because it transmits the bacteria that cause huanglongbing (HLB). HLB limits citrus production globally. We evaluated the toxicity of sulfoxalor against D. citri and its parasitoid, Tamarixia radiata Waterston. Sulfoxaflor was as toxic as imidacloprid to adult D. citri. The LC₅₀ values for sulfoxaflor and imidacloprid were 8.17 and 5.7 µg AI mL^?1, respectively. The LC₅₀ of sulfoxaflor for T. radiata adults was 3.3 times greater than for D. citri adults. Treatment with sulfoxaflor resulted in reduced oviposition, development of nymphs, and emergence of adult D. citri on plants, as compared with controls. The lowest concentration that reduced adult emergence was 0.6 µg AI mL^?1. There was reduced feeding by D. citri adults on leaves treated with sulfoxaflor. The residual toxicity of sulfoxaflor was equivalent to imidacloprid. Under field conditions, formulated sulfoxaflor reduced populations of D. citri compared with untreated controls. Sulfoxaflor is a novel mode of action and is an effective tool for D. citri management.     

Bioresidual and integrated pest management status of a biorational agent and a novel insecticide against whitefly and its key parasitoids

The effects of continuous exposure of the adult and crawler stages of the whitefly, Trialeurodes vaporariorum, and adult of the parasitoids Encarsia formosa and Eretmocerus eremicus to spray deposits of potassium salts of a fatty acid and diafenthiuron applied at recommended rates were evaluated. French bean, Phaseolus vulgaris Prince, plants were sprayed and the adults confined on them using modified 5 cm Petri dishes. Fresh (4 - 5-h-old) deposits of fatty acids resulted in a 10.7% mortality rate of whitefly adults and 8.0 and 10.7% mortality rates of E. formosa and E. eremicus adults respectively, while fresh deposits of diafenthiuron resulted in a 62.7% mortality rate of whitefly adults and 12.0 and 14.7% mortality rates of E. formosa and E. eremicus respectively. The mortality rate (6.9 and 69.7%) of whitefly crawlers was recorded when exposed to 24-h-old deposits of fatty acids and diafenthiuron respectively. The mortality rate declined as the deposits aged. Adult parasitoid emergence from the treated pupae was unaffected. Spray deposits of diafenthiuron were effective against whitefly for up to 2-3 weeks in comparison with fatty acids, which were effective only when sprayed. Both products were harmless to adults as well as pupae of both parasitoids irrespective of the exposure period (age of deposits) tested (IOBC Class 1). These insecticides can be included in integrated pest management strategies against whitefly with the fatty acids used on horticultural crops.