Leaf surfaces and the bioavailability of pesticide residues     

Chowdhury AB  Jepson PC  Howse PE  Ford MG 《Pest management science》2001,57(5):403-412

Laboratory bioassays were carried out to determine the toxicity to Folsomia candida Willem (Collembola: Isotomidae) of residues of a pyrethroid insecticide, deltamethrin, and an organophosphorus insecticide, dimethoate, on different leaf surfaces. The test leaves included a range of species and leaves of different ages. Dose-response relationships were estimated for F candida walking over the various treated leaf substrates. Probit analysis was used to estimate the means and standard deviations of the associated tolerance distributions expressed as gAIha-1. Parallelism tests were undertaken to compare the susceptibilities of F candida to the two compounds applied to the different leaf surfaces. On deltamethrin-treated leaf surfaces, the LD50 values for F candida varied from 6.36 to 77.14 gAIha-1. F candida was least susceptible to deltamethrin residues when applied to leaves of dwarf bean (Phaseolus vulgarus L) and the highest susceptibility was observed following application to leaves of seedlings of barley (Hordeum vulgare L). In contrast, the LD50 values observed for dimethoate treatments did not differ significantly between leaf types, ranging from 1.35 to 8.69 gAIha-1. The laboratory data on susceptibility of F candida on different leaf types for different pesticides can be used to investigate the role of leaf surface properties in modifying the toxicity of applied pesticides to exposed invertebrates.  相似文献   

溴氰菊酯胁迫下罗非鱼组织中过氧化氢酶和单胺氧化酶的变化   总被引：2，自引：0，他引：2  

陈家长  吴伟  瞿建宏  胡庚东 《农业环境科学学报》2006,25(6):1441-1445

以罗非鱼Tilipia为试验鱼类,采用人工水族箱培养法,研究了其暴露于不同浓度溴氰菊酯后组织中过氧化氢酶CAT和单胺氧化酶MAO活性的动态变化。结果表明,罗非鱼肌肉和肝脏组织中的CAT正常值分别为(8.56±0.2)U.mg-1prot和(15.48±0.1)U.mg-1prot,MAO的正常值分别为(0.045±0.002)U.h-.1mg-1prot和(0.465±0.010)U.h-.1mg-1prot,均是肝脏组织高于肌肉组织。采用不同浓度的溴氰菊酯处理罗非鱼25d,除了1.0μg.L-1浓度组罗非鱼体内CAT和MAO与对照组相比无显著差异外,其余各浓度组的CAT和MAO均发生了明显的变化,两者的变化趋势正好相反。CAT的变化规律为先降低后升高,即溴氰菊酯对罗非鱼体内的CAT具有一定的抑制作用,可使鱼体内的CAT失活,且这种变化幅度肝脏比肌肉大。MAO的变化规律为先升高后降低再恢复,即溴氰菊酯对罗非鱼体内的MAO具有诱导和激活的作用,这种变化的幅度肝脏比肌肉小一些。研究表明,1.0μg.L-1以下的溴氰菊酯对罗非鱼没有生化毒性影响,罗非鱼组织中的CAT和MAO可作为生物标志物来评价农药对鱼类的生化毒性。  相似文献   

Identification and characterisation of ten glutathione S-transferase genes from oriental migratory locust, Locusta migratoria manilensis (Meyen)     

Qin G  Jia M  Liu T  Xuan T  Yan Zhu K  Guo Y  Ma E  Zhang J 《Pest management science》2011,67(6):697-704

BACKGROUND: Synthetic pyrethroids are the primary insecticides that are widely used for controlling Locusta migratoria manilensis (Meyen), a major pest in eastern and southern Asia and the Pacific region. In this paper, ten cDNAs encoding glutathione S‐transferases (GSTs) were sequenced and characterised in L. migratoria manilensis. The effects of deltamethrin on the ten GST gene expressions were studied. RESULTS: Phylogenetic analysis revealed nine GSTs in three different classes, including seven in sigma, one in delta and one in theta. The remaining GST (LmGSTu1) was unclassified. RT‐PCR analysis showed that most GST genes were expressed in all tissues examined, including the foregut, midgut, gastric caecum, hindgut, Malpighian tubules, fat bodies, muscles, spermaries and ovaries, except that LmGSTs2, LmGSTs4, LmGSTs7 and LmGSTu1 were expressed in several tissues. LmGSTu1 appeared to be the only gene whose expressions could not be detected in eggs. Real‐time quantitative PCR showed that deltamethrin at 0.08 and/or 0.12 µg mL^?1 increased almost all ten GST gene expressions in third‐instar nymph locusts. However, deltamethrin at 0.16 and/or 0.2 µg mL^?1 decreased the expressions of LmGSTd1, LmGSTs1, LmGSTs5 and LmGSTs6. CONCLUSION: The increases in GST gene expressions after deltamethrin exposure in L. migratoria manilensis might result in its elevating tolerance to other insecticides and xenobiotics. Copyright © 2011 Society of Chemical Industry  相似文献   

Long-term efficacy of a deltamethrin-impregnated collar for the control of the Australian paralysis tick, Ixodes holocyclus, on dogs     

Webster MC  Fisara P  Sargent RM 《Australian veterinary journal》2011,89(11):439-443

Objective To determine the duration of efficacy of a 4% deltamethrin‐impregnated collar for dogs (Scalibor® ProtectorBand, MSD Animal Health) against adult female paralysis ticks (Ixodes holocyclus). Procedures A controlled pen study was conducted. Dogs were artificially infested at 14‐day intervals with unfed adult female ticks for up to 140 days following application of the collar to the dogs. Efficacy was assessed by manually counting ticks on dogs at 24, 48 and 72 h after each infestation. Results Efficacy at the 72‐h count was 96% after the day 14 tick infestation. The 72‐h efficacy remained above 94% from the day 14 to the day 98 infestations, when efficacy was still 99.5%. Efficacy at 72 h was above 90% after the day 112 infestation and was still 93% at 72 h after the day 140 infestation. Conclusions The deltamethrin‐impregnated collar gave greater than 90% control of paralysis ticks for at least 14 weeks.  相似文献   

农药对烟蚜茧蜂的影响   总被引：2，自引：0，他引：2  

陈家骅  陈达荣  李芳  张玉珍 《中国生物防治》1989,(3)

以5种杀蚜农药的田间使用浓度,对烟蚜茧蜂的成蜂和僵蚜体内该蜂的毒杀作用进行了研究。对烟蚜茧蜂成蜂测定的结果,其毒性顺序为:溴氰菊酯>功夫菊酯>氧化乐果>来福灵>杀灭菊酯。在田间实际用药浓度下,来福灵对成蜂影响最小,但喷药后24小时接蜂,48小时后,其存活率亦仅40％。而对僵蚜中的蚜茧蜂均影响较小。其中氧化乐果羽化率达96.6％,杀灭菊酯、来福灵和溴氰菊酯达60.0～66.3％。  相似文献   

近红外光谱法快速测定农药中溴氰菊酯含量   总被引：3，自引：0，他引：3  

熊艳梅  李春子  王冬  段佳  段云青  闵顺耕 《农药学学报》2010,12(3):367-370

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。  相似文献   

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

Mónica D Germano  Claudia V Vassena  María I Picollo 《Pest management science》2010,66(7):705-708

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  相似文献   

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

John E Casida 《Pest management science》2010,66(11):1163-1170

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  相似文献   

Insensitive Acetylcholine Receptor Conferring Resistance of Plutella xylostella to Nereistoxin Insecticides     

Luo-gen CHENG  Guang YU  Zi-hao CHEN  Zhong-yin LI 《中国农业科学(英文版)》2008,7(7):847-852

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.  相似文献   

辛硫磷与溴氰菊酯混配对防治美洲大蠊增效机理研究     

高永闯  王淑敏  刘秀华  刘安西 《河北农业大学学报》2007,30(3):69-72

利用电生理和生化方法,以美洲大蠊为材料,研究辛硫磷与溴氰菊酯混用的增效机理。结果表明:辛硫磷与溴氰菊酯混配,特别是1×10-5mol/L辛硫磷与1×10-6mol/L溴氰菊酯混配,兴奋性突触后电位(EPSP)开始兴奋时间比单用溴氰菊酯缩短了67%,阻断时间缩短了36 min以上,说明混剂提高了乙酰胆碱的释放和在突触间隙的积累。生化分析认为,混剂增效的原因之一是提高了对靶标酶——AchE的抑制。  相似文献