In vitro and in vivo effects of some pesticides on glucose-6-phosphate dehydrogenase enzyme activity from rainbow trout (Oncorhynchus mykiss) erythrocytes

We investigated the in vitro and in vivo effects of some pesticides on rainbow trout erythrocyte glucose-6-phosphate dehydrogenase enzyme. The enzyme was purified 1691-fold with a specific activity of 16.235 U/mg protein and a yield of 63%. Cypermethrin, and propoxur inhibited glucose-6-phosphate dehydrogenase enzyme in vitro and deltamethrin inhibited both in vivo and in vitro. The obtained IC₅₀ values for deltamethrin, cypermethrin, and propoxur were 0.63, 1.02, and 12 mM, respectively. The activity of the control was determined as 5.17 ± 0.62 U/g Hb in in vivo studies. The enzyme activities of the groups treated with 0.25 g/L deltamethrin were measured at 6, 12, 24, 48, and 72 h, and found to be 4.32 ± 0.47, 3.57 ± 0.39, 3.47 ± 0.45, 2.86 ± 0.37, and 2.31 ± 0.32 U/g Hb. In vivo experiments showed that deltamethrin significantly inhibited the G6PD enzyme activity after the 48th h (p < 0.05).     

溴氰菊酯对马铃薯腐烂茎线虫的毒力及对其运动和摄食的影响

采用药液浸渍法、沙柱法以及与荧光染料Cy3共孵育的方法,以丙溴磷、克百威和阿维菌素为对照药剂,测定了溴氰菊酯对马铃薯腐烂茎线虫Ditylenchus destructor的毒力以及对其运动扩散和摄食的影响。结果表明:溴氰菊酯对马铃薯腐烂茎线虫具有一定的杀灭活性,其LC50值为459.8mg/L,活性低于丙溴磷(159.9mg/L)、克百威(331.9mg/L)和阿维菌素(257.3mg/L);溴氰菊酯对马铃薯腐烂茎线虫运动扩散的抑制作用IC50值为3.1mg/L,其活性低于阿维菌素(0.8mg/L),但高于丙溴磷(8.3mg/L)和克百威(16.1mg/L)。当丙溴磷和克百威质量浓度分别低至0.6和40mg/L时,可刺激90%以上的线虫摄食;当丙溴磷和克百威质量浓度最低分别为360和300mg/L时,可抑制全部线虫的摄食;溴氰菊酯与阿维菌素则对线虫的摄食无刺激作用;用10mg/L的丙溴磷处理线虫2h后再分别用阿维菌素和溴氰菊酯处理,发现阿维菌素和溴氰菊酯质量浓度最低分别为20和200mg/L时可抑制全部马铃薯腐烂茎线虫的摄食。研究表明,溴氰菊酯对马铃薯腐烂茎线虫具有较高的活性,其在线虫防治领域的开发应用潜力较好。     

马铃薯桃蚜对拟除虫菊酯类杀虫剂的敏感性及其体内羧酸酯酶活性研究

为明确内蒙古马铃薯主要种植区马铃薯桃蚜的抗药性水平及抗性形成机制,采用室内生物测定方法,检测了内蒙古呼和浩特市及呼和浩特武川县马铃薯桃蚜田间种群(分别简称为呼市种群和武川种群)和室内饲养未接触任何药剂的马铃薯桃蚜敏感种群对7种拟除虫菊酯类杀虫剂的敏感性,并对供试各种群桃蚜的羧酸酯酶(CarE)活性进行了研究。结果表明:相对于敏感种群,呼市种群和武川种群对氯氰菊酯均产生了高水平抗性(抗性倍数为74.11和549.4);呼市种群对联苯菊酯产生了中等水平抗性(16.03倍),对氰戊菊酯、高效氯氰菊酯和高效氯氟氰菊酯仍保持敏感(1.00~4.00倍);武川种群对溴氰菊酯(10.14倍)、甲氰菊酯(26.46倍)和联苯菊酯(33.74倍)处于中等抗性水平,对高效氯氰菊酯、氰戊菊酯和高效氯氟氰菊酯仍较为敏感(50值分别为0.54、1.07和0.93 nmol/L。三唑磷分别与高效氯氰菊酯和溴氰菊酯联用可显著增强其毒力,表明三唑磷与这两种拟除虫菊酯类药剂复配在武川和呼市马铃薯桃蚜防治中具有很好的应用潜力。     

Deltamethrin induced alterations of hematological and biochemical parameters in fingerlings of Catla catla (Ham.) and their amelioration by dietary supplement of vitamin C

The present study was carried out to investigate the sub-lethal toxicity of technical grade deltamethrin (a synthetic pyrethroid) of concentration 1.61 μg/L (1/3rd of 96 h LC₅₀) on hematological and biochemical parameters of catla (Catla catla) fingerlings and its amelioration through dietary vitamin C. The deltamethrin exposed fishes were fed with different levels of supplemented vitamin C such as 50, 250, 500 and 1000 mg/kg diet to see its ameliorating effect by assaying hematological parameters viz. total erythrocyte count (TEC), total leukocyte count (TLC), hemoglobin content (Hb), total serum protein, albumin, globulin, albumin–globulin ratio and biochemical parameters such as lactate dehydrogenase (LDH), acetylcholine esterase (AChE), alanine amino transferase (ALT), aspartate amino transferase (AST), total adenosine triphosphatase (ATPase), magnesium adenosine triphosphatase (Mg²⁺-ATPase) and sodium potassium adenosine triphosphatase (Na⁺, K⁺-ATPase) activities. The finding of this study showed that deltamethrin had negative effect on the hematological and biochemical parameters of Catla catla. The experimental group, which was exposed to deltamethrin and fed with normal diet showed significantly lower values (P ? 0.05) of all parameters studied except ALT activity. This might be due to possible disruption of hematopoiesis and proteosynthesis. However, the fish fed with varied concentration of vitamin C in diets neutralized the toxic effect of deltamethrin, as evidenced by significantly lowered hematological and biochemical response. Vitamin C @ 1000 mg/kg diet was the most effective in amelioration of harmful effect of deltamethrin on hematological and biochemical parameters of catla fingerlings. The result suggests that vitamin C can be effectively used to neutralize the toxic effect of deltamethrin on catla.     

Insecticide resistance status of the codling moth Cydia pomonella (Lepidoptera: Tortricidae) from Greece

The codling moth Cydia pomonella L. is controlled mostly with chemical insecticides in Greece and control failures have been reported. However, there are no insecticide resistance studies in the country as yet. We examined the insecticide resistance status of 33 and 38 populations of fifth-instar non-diapausing and diapausing larvae, respectively by applying bioassays, biochemical and DNA diagnostics. Diagnostic concentrations of azinphos-methyl, phosalone, deltamethrin, thiacloprid, fenoxycarb, tebufenozide, methoxyfenozide and diflubenzuron were used in bioassays. Almost all populations showed reduced susceptibility to at least one insecticide and approximately half of them to all insecticides examined compared to a laboratory susceptible strain used as reference. However, only one out of six populations tested showed reduced susceptibility in ovicidal tests with fenoxycarb. Cross-resistances were observed among most insecticides, except from the pairs fenoxycarb–phosalone and thiacloprid–phosalone, in non-diapausing larvae. The more obvious biochemical marker associated with the reduced susceptibility observed in both larval instars was elevated cytochrome P₄₅₀ polysubstrate monooxygenases activity, followed by elevated glutathione-S-transferase activity and reduced carboxylesterases activity. Neither sodium channel nor AChE known resistance mutations were found in any of the approximately 1000 individuals of each larval instar screened with diagnostic PCR. Actions for Integrated Resistance Management and application of alternative control methods are discussed.     

Rational use of deltamethrin on potato against Leptinotarsa decemlineata and other significant pests1

In trials of deltamethrin against Leptinotarsa decemlineata on potato crops in several European and Mediterranean countries, high levels of efficacy were obtained. Recommendations are accordingly presented for rational use of this insecticide to control L. decemlineata, and also several other important insect pests of potato, taking due account of results on the safety of deltamethrin for the user, consumer and environment.     

星豹蛛PaCYP3001U16基因的克隆与表达分析

为探究细胞色素P450基因在星豹蛛Pardosa astrigera体内的表达特性及对溴氰菊酯胁迫的响应,采用反转录PCR技术克隆其细胞色素P450基因并进行序列分析,采用实时荧光定量PCR(quantitative real-time PCR,RT-qPCR)技术分析其在星豹蛛各发育阶段及雌雄成蛛不同部位的表达水平,同时分析其在溴氰菊酯不同浓度胁迫下和不同处理时间后的表达模式。结果显示,在星豹蛛雌成蛛中克隆得到1个细胞色素P450基因,其开放阅读框为1 473 bp,编码490个氨基酸,命名为PaCYP3001U16(GenBank登录号为MZ643213)。PaCYP3001U16基因在星豹蛛各发育阶段均有表达,其中在成蛛期的表达量最高,在6龄幼蛛期的表达量最低;该基因在雌雄成蛛腹部的表达量显著高于在头胸部及足部的表达量。星豹蛛雄成蛛经LC10(5.151 mg/L)、LC30(8.619 mg/L)和LC50(12.311 mg/L)溴氰菊酯处理12 h,PaCYP3001U16基因的表达量均被抑制,且在LC50处理下表达量最低。PaCYP3001U16基因经LC30溴氰菊酯处理...     

Evaluation of toxicity and genotoxic effects of spinosad and deltamethrin in Drosophila melanogaster and Bactrocera oleae

BACKGROUND: The insecticides spinosad and deltamethrin are being increasingly used in pest management programmes. In order to assess further their toxic effects to target and non‐target insect species, an evaluation was made of their insecticidal profile on Bactrocera oleae (Rossi) and Drosophila melanogaster (Meig.). Moreover, possible genotoxic effects of the two pesticides were investigated using the somatic mutation and recombination test (SMART) in D. melanogaster. RESULTS: Both insecticides were highly effective against B. oleae, exhibiting similar LC₅₀ values. Moreover, they were found to be more effective against Bactrocera than against Drosophila adults. However, spinosad was significantly more toxic than deltamethrin to D. melanogaster. The results showed a lack of genotoxic activity of both insecticides under the in vivo experimental procedure employed, at least at applied doses. CONCLUSION: The present study provides information for lethal and sublethal effects of spinosad and deltamethrin against a target and a non‐target species. Both insecticides can exert high toxicity to B. oleae when adults are exposed even to very low doses for long periods of time. The results contribute to the database on the genotoxic potential of spinosad and deltamethrin, suggesting a safety profile for both insecticides. Copyright © 2011 Society of Chemical Industry     

A new aqueous suspension concentrate formulation of cis‐permethrin and its insecticidal activity

Isomers of pyrethroids usually have different insecticidal activities. Permethrin, a non‐cyano pyrethroid, is not an exception and cis‐permethrin is much more active than the trans‐isomer against Triatoma infestans, vector of Chagas' Disease in Argentina. The large‐scale separation of cis‐ and trans‐permethrin was performed by successive recrystallizations from ethanol‐water mixtures. An aqueous suspension concentrate (flowable) formulation of pure crystalline cis‐permethrin was prepared and assayed for its insecticidal activity on wood and ceramic surfaces against nymph V of T infestans. This formulation was at least three times more effective than deltamethrin, with LC₅₀ values on ceramic of 0.11 µg cm⁻² and 0.33 µg cm⁻² respectively. On wood surfaces, the LC₅₀ value was 0.57 µg cm⁻² compared with 3.20 µg cm⁻² for deltamethrin. Against other insect species such as Periplaneta americana, Aedes aegypti and Culex quinquefasciatus, the suspension concentrate formulation of cis‐permethrin was, however, less effective than similar formulations of deltamethrin or β‐cypermethrin. © 2000 Society of Chemical Industry     

Suppression ofbactra venosana,a potential natural enemy ofcyperus rotundus,bytrichogrammatoidea bactrae in Bangalore,India

Bactra venosana Zeller (Lepidoptera: Tortricidae) is the predominant natural enemy ofCyperus rotundas L. in Bangalore, India. Although the insect was found to have potential, it was incapable of suppressing the weed due to low incidence. Laboratory studies involving field-collected insect stages revealed that heavy parasitism of eggs byTrichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae) was the most important mortality factor suppressing its potentiality.     

Spatial and temporal changes in acetolactate synthase activity as affected by new herbicide ZJ0273 in rapeseed, barley and water chickweed

Propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzylamino)benzoate (ZJ0273), derived from a precursor compound pesticide (a derivative of 2-pyrimidinyloxy-N-aryl benzoate), is a novel herbicide used in the rapeseed field. This paper studied the differential tolerance or susceptibility of four plant species viz. Brassica napus L. (rapeseed), Hordeum vulgare L. (barley), Malachium aquaticum (L.) Fries (water chickweed), and Alopecurus aequalis Sobol. (equal alopecurus), to various concentrations of ZJ0273, based on the rate of inhibition of acetolactate synthase (ALS) activity. Brassica napus was observed as the most tolerant among four species in which ALS activity in vivo was hardly affected by ZJ0273 at 100 mg/L (recommended dose in the rapeseed field). In contrast, H. vulgare was found to be more susceptible which was reflected in the relative decline of ALS activity and lower biomass production even under at a lower rate of 10 mg/L of ZJ0273. The two weed species exhibited moderate susceptibility as compared to H. vulgare. The present study confirmed that ZJ0273 at 100 mg/L is the optimal dose of herbicide for rapeseed field. Seedling stage was critical in determining the tolerance of crops and susceptibility of weeds which indicated that over seven leaf stage was much safer for rapeseed whereas the two leaf stage juvenile water chickweed was more susceptible to the same rate of ZJ0273. Spatial and temporal variations in ALS activity as affected by 100 mg/L ZJ0273 in water chickweed, rapeseed and barley also suggested that the synchronized sampling based on the tissue position and seedling stage was necessary to examine precisely, the special difference in tolerance or susceptibility to ALS-inhibiting herbicide. The uppermost younger leaf seemed to be the most appropriate sample for evaluation. Furthermore, the variant tendency of ALS activity from different parts of plants between monocotyledons and dicotyledons to ZJ0273 treatments showed differential response which revealed some possible mechanism related to the altered absorption and translocation of the herbicide.     

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

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     

菊酯类药剂对草地贪夜蛾的毒力及对钠离子通道的诱导特性

为明确菊酯类药剂对草地贪夜蛾Spodoptera frugiperda的防治效果,采用点滴法在室内测定高效氯氟氰菊酯、高效氯氰菊酯、联苯菊酯、溴氰菊酯和茚虫威原药对草地贪夜蛾3龄幼虫的毒力,利用实时荧光定量PCR技术测定3龄幼虫在这5种药剂诱导不同时间下其体内钠离子通道基因片段的表达量变化。结果显示,高效氯氟氰菊酯、溴氰菊酯、联苯菊酯、茚虫威和高效氯氰菊酯这5种药剂处理草地贪夜蛾3龄幼虫24 h后的LD50值分别为74.911、83.280、152.662、179.372、567.250 mg/L;处理48 h后的LD50值分别为18.946、67.874、120.888、132.790、461.635 mg/L;同时发现草地贪夜蛾3龄幼虫钠离子通道基因的表达均呈现不被诱导或诱导下调现象,表明草地贪夜蛾幼虫可通过降低靶标基因的表达量进而减少药剂对其的毒性。表明供试4种拟除虫菊酯类药剂和1种氯虫苯甲酰胺类药剂可作为草地贪夜蛾田间应急防控药剂施用。     

Efficacy of insecticide mixtures against pyrethroid‐ and organophosphate‐resistant populations of Spodoptera litura (Lepidoptera: Noctuidae)

BACKGROUND: Spodoptera litura (F.) is an important pest worldwide, with over 112 host plants, and is exposed to insecticides throughout the year, resulting in the rapid development of resistance. Insecticide mixtures can delay the development of resistance more effectively than sequences or rotations. Cypermethrin, deltamethrin, profenofos, chlorpyrifos and fipronil were assessed separately and in mixtures against laboratory susceptible S. litura and two field‐collected populations. RESULTS: The field‐collected population from Khanewal (KWL) was significantly more resistant to cypermethrin, deltamethrin, chlorpyrifos and profenofos than one collected from Muzaffar Garh (MGH). Mixtures of cypermethrin + chlorpyrifos or profenofos and of deltamethrin + chlorpyrifos or profenofos at 1:1, 1:10 and 1:20 ratios significantly increased (P < 0.01) toxicity to cypermethrin and deltamethrin in field populations. The combination indices of cypermethrin + chlorpyrifos at 1:1 and 1:10 ratios and cypermethrin + fipronil at 1:1, 1:10 and 1:20 ratios for the KWL strain and of cypermethrin + profenofos or fipronil at 1:1, 1:10 and 1:20 ratios for MGH were significantly below 1, suggesting synergistic interactions. The inhibitors DEF and PBO largely overcame resistance to deltamethrin, cypermethrin and profenofos, suggesting that resistance to the insecticides was associated with esterase and monooxygenase detoxification respectively. CONCLUSION: Chlorpyrifos, profenofos and fipronil could be used in mixtures to restore cypermethrin and deltamethrin susceptibility. These findings may have considerable practical implications for S. litura resistance management. Copyright © 2008 Society of Chemical Industry     

Cross-resistance between a Bacillus thuringiensis Cry toxin and non-Bt insecticides in the diamondback moth

BACKGROUND: Bacillus thuringiensis Berliner (Bt) crystal (Cry) toxins are expressed in various transgenic crops and are also used as sprays in integrated pest management and organic agricultural systems. The diamondback moth (Plutella xylostella L.) is a major worldwide pest of crucifer crops and one that has readily acquired field resistance to a broad range of insecticides.RESULTS: Selection of a subpopulation of the P. xylostella SERD4 population with the pyrethroid deltamethrin increased resistance to both deltamethrin and Cry1Ac relative to an unselected subpopulation. Selection of a second subpopulation with the Bt toxin Cry1Ac also increased resistance to both Cry1Ac and deltamethrin. A complementation test between the Cry1Ac-selected and deltamethrin-selected subpopulations suggested the presence of a common genetic locus or loci that control resistance to both insecticides. A piperonyl butoxide analogue with potent inhibitory activity against insect esterases significantly increased the toxicity of Cry1Ac and deltamethrin against the respective resistant subpopulations, but showed no such synergism with the unselected subpopulation of SERD4.CONCLUSION: Selection of one resistance phenotype resulted in the simultaneous selection of the other. This phenomenon could be due to a single mechanism acting against both classes of insecticide or to genetically linked, but separate, mechanisms.     

The insecticidal and acaricidal actions of compounds fromAzadirachta indica (A. Juss.) and their use in tropical pest management

The pest control potential demonstrated by various extracts and compounds isolated from the kernels and leaves of the neem plant (Azadirachta indica) A. Juss. (Meliaceae) seem to be of tremendous importance for agriculture in developing countries. Laboratory and field trial data have revealed that neem extracts are toxic to over 400 species of insect pests some of which have developed resistance to conventional pesticides, e.g. sweet potato whitefly (Bemisia tabaci Genn. Diptera: Aleyrodidae), the diamond back moth (Plutella xylostella L. Lepidoptera: Plutellidae) and cattle ticks (Amblyomma cajennense F. Acarina: Ixodidae andBoophilus microplus Canestrini. Acarina: Ixodidae). The compounds isolated from the neem plant manifest their effects on the test organisms in many ways, e.g. as antifeedants, growth regulators, repellents, toxicants and chemosterilants. This review strives to assess critically the pest control potential of neem extracts and compounds for their use in the tropics. This assessment is based on the information available on the wide range of pests against which neem extracts and compounds have proven to be toxic, toxicity to non-target organisms, e.g. parasitoids, pollinators, mammals and fish, formulations, stability and phytotoxicity.     

直接竞争酶联免疫吸附分析法测定小白菜中溴氰菊酯的残留量

应用作者所在实验室自制的、对溴氰菊酯具有特异性亲和力的多克隆抗体和酶标半抗原,建立了包被抗体-酶标半抗原直接竞争酶联免疫吸附分析法(DC-ELISA)。小白菜样品经超声提取、浓缩和10%甲醇定容后采用DC-ELISA法测定,并采用高效液相色谱法进行验证。结果表明:在抗体包被浓度为2.0 mg/L、辣根过氧化物酶(HRP)标记溴氰菊酯半抗原稀释2.0×105倍、包被介质为pH 7.2 PB、反应介质为含0.125 mol/L NaCl pH 6.8 PB的优化条件下,DC-ELISA法检测溴氰菊酯的线性范围为0.10~10 mg/L,溴氰菊酯对抗体-酶标半抗原反应的抑制中浓度(IC50)为1.68 mg/L,相对标准偏差(RSD,n=5)为2.11%,IC10值为0.16 mg/L。在5、1和0.2 mg/kg 3个添加水平下,DC-ELISA法测定小白菜中溴氰菊酯的平均回收率分别为97%、106%和95%,RSD(n=5)分别为8.5%、8.1%和8.1%。高效液相色谱法同步测定小白菜中添加0.2 mg/kg溴氰菊酯的回收率为107%。本研究建立的DC-ELISA法可用于小白菜中溴氰菊酯含量的快速测定。     

基于文献计量学的沙漠蝗研究动态分析

为深入了解沙漠蝗在全球范围的研究动态和趋势,该文利用文献计量学方法,以知网、万方、维普、Web of Science和CAB Abstracts为数据源,对1910—2021年国内外发表的3 006篇沙漠蝗文献进行统计分析。结果表明,随着时间的推移有关沙漠蝗的文献数量整体上呈上升趋势,其暴发式增长出现在20世纪70年代。Journal of Experimental Biology和《植物保护学报》是发文量最多的外文期刊和中文期刊,分别为99篇和6篇。在外文发文量方面,英国、德国和美国等国家的研究机构和作者名列前茅;发文量分别为331、270和234篇。在中文发文量方面,中国农业科学院植物保护研究所为发表沙漠蝗相关中文文献最多的研究机构,为6篇。沙漠蝗的研究热点与其可持续防控高度相关,尤其侧重生物防治和有害生物综合治理方面的研究。     

Insecticide resistance status of Aedes aegypti (L.) from Colombia

BACKGROUND: To evaluate the insecticide susceptibility status of Aedes aegypti (L.) in Colombia, and as part of the National Network of Insecticide Resistance Surveillance, 12 mosquito populations were assessed for resistance to pyrethroids, organophosphates and DDT. Bioassays were performed using WHO and CDC methodologies. The underlying resistance mechanisms were investigated through biochemical assays and RT‐PCR. RESULTS: All mosquito populations were susceptible to malathion, deltamethrin and cyfluthrin, and highly resistant to DDT and etofenprox. Resistance to lambda‐cyhalothrin, permethrin and fenitrothion ranged from moderate to high in some populations from Chocó and Putumayo states. In Antioquia state, the Santa Fe population was resistant to fenitrothion. Biochemical assays showed high levels of both cytochrome P450 monooxygenases (CYP) and non‐specific esterases (NSE) in some of the fenitrothion‐ and pyrethroid‐resistant populations. All populations showed high levels of glutathione‐S‐transferase (GST) activity. GSTe2 gene was found overexpressed in DDT‐resistant populations compared with Rockefeller susceptible strain. CONCLUSIONS: Differences in insecticide resistance status were observed between insecticides and localities. Although the biochemical assay results suggest that CYP and NSE could play an important role in the pyrethroid and fenitrothion resistance detected, other mechanisms remain to be investigated, including knockdown resistance. Resistance to DDT was high in all populations, and GST activity is probably the main enzymatic mechanism associated with this resistance. The results of this study provide baseline data on insecticide resistance in Colombian A. aegypti populations, and will allow comparison of changes in susceptibility status in this vector over time. Copyright © 2011 Society of Chemical Industry     

溴氰菊酯降解菌的分离筛选与应用潜力评价

为解决杀虫剂溴氰菊酯的残留污染问题及丰富其降解菌资源库,采用富集培养法,从长期被溴氰菊酯污染的土壤中分离筛选到1株高效降解菌株XQ08,经形态学特征、生理生化及16S rDNA鉴定其为嗜麦芽寡养单胞菌Stenotrophomonas maltophilia,并对菌株发酵条件、菌剂制备方法及应用潜力进行了初步研究。结果表明:在纯培养条件下,XQ08菌株5 d内对50 mg/L溴氰菊酯的降解率可达66.76%;在35 ℃、pH=8及以麦芽糖为碳源、氯化铵为氮源的条件下可获得理想的发酵效果,同时明确了XQ08液体菌剂的制备方法。分别在室内盆栽与田间种植的香菜上喷施高剂量 (推荐剂量10倍,有效成分6.25 g/hm2) 的25 g/L溴氰菊酯乳油,于施药后2、24和48 h施用XQ08菌剂,3、5、7和9 d后,香菜上溴氰菊酯的降解率分别超过20%、50%、60%及70%;7 d后施用菌剂处理组溴氰菊酯残留量均低于0.5 mg/kg,9 d后残留量均低于0.2 mg/kg。本研究首次报道了嗜麦芽寡养单胞菌对溴氰菊酯的降解,发现其XQ08菌剂可有效促进溴氰菊酯的降解,且其降解符合一级动力学特征。嗜麦芽寡养单胞菌XQ08菌株能有效降低或清除蔬菜上的溴氰菊酯残留,具有较好的应用潜力和开发价值。