土壤和水体中20种除草剂的气相色谱-质谱法多残留分析

建立了土壤和水体中20种除草剂残留的气相色谱-质谱(GC-MS)分析方法。土壤样本通过乙腈提取,Florisil固相萃取柱净化,V(石油醚):V(乙酸乙酯)=9:1洗脱,GC-MS测定;水体样本用C18固相萃取柱进行富集和净化,以V(甲醇):V(乙酸乙酯)=1:1洗脱,GC-MS测定。20种除草剂在土壤和水体中的平均添加回收率分别为72%～109%和77%～113%,相对标准偏差(RSD)分别在0.15%～16.5%和0.45%～16.3%之间,方法定量限(LOQ)在土壤中为0.01 mg/kg,在水体中为0.1 μg/L。用所建方法可同时检测土壤和水中20种常用除草剂,方法净化效果好、灵敏度高、重现性好、简便快速。     

滤过型净化柱净化-超高效液相色谱-三重四极杆/复合线性离子阱质谱法测定草鱼中11种农药残留

采用推杆式滤过型净化柱净化,结合超高效液相色谱-三重四极杆/复合线性离子阱质谱仪(UPLC-QTRAP-MS/MS)建立了草鱼样品中11种农药残留的检测方法。以乙腈为提取剂,样品经超声、冷冻、离心后,上清液采用以50 mg PSA为净化填料的推杆式滤过型净化柱进行1次快速净化;超高效液相色谱快速分离,三重四极杆/复合线性离子阱质谱仪进行测定。基质匹配法制作标准曲线,外标法定量。结果表明:11种农药在1.0~50.0 μg/kg内的线性关系良好,相关系数均大于0.99;定量限为1.0~2.0 μg/kg。不同添加水平下的回收率为83%~119%,日内相对标准偏差为2.6%~20%,日间相对标准偏差为0.7%~15%。该方法经济、简便、高效,灵敏度高,重复性好,可作为草鱼中农药残留的日常检测方法。     

QuEChERS/GC-MS快速分析土壤中的苯醚甲环唑残留

采用QuEChERS方法结合气相色谱-质谱(GC-MS)法建立了土壤中苯醚甲环唑残留的快速分析方法。用乙腈提取土壤中的苯醚甲环唑,基质固相分散净化后,GC-MS外标法定量。结果表明:方法具有快速、简便、高效、灵敏等优点,苯醚甲环唑在0.005~0.5 μ g/mL质量浓度范围内呈线性关系,相关系数达0.999。土壤中苯醚甲环唑添加水平为0.01~0.5 mg/kg时,平均回收率为74.2%~91.9%,相对标准偏差在4.59%~6.62%之间,检出限(LOD)为0.002 mg/kg,定量限(LOQ)为0.005 mg/kg。田间土壤消解动态试验表明:苯醚甲环唑在北京土壤中的消解半衰期为17.4 d,属于易降解农药。     

气相色谱-串联质谱法快速检测当归中102种农药残留

建立了当归中102种农药残留的快速检测方法。样品采用优化的QuEChERS前处理方法，利用气相色谱-串联质谱 (GC-MS/MS) 检测，动态多反应监测 (dMRM) 模式，基质匹配外标法定量。结果表明:在样品前处理过程中，经对提取溶剂、提取体系、净化体系的组成和用量进行筛选优化后，样品采用乙腈、1.0 g氯化钠、4.0 g无水硫酸镁、1.0 g柠檬酸钠和0.5 g柠檬酸二钠盐提取，无水硫酸镁800 mg、PSA 150 mg、C₁₈ 150 mg净化，通过基质匹配外标法校正，当归中基质效应对目标化合物的定性、定量影响明显减弱。在0.02~0.64 mg/kg范围内，102种农药的质量浓度与对应的峰面积间呈良好的线性关系，R2均大于0.99，检出限为0.002 5~0.025 mg/kg，定量限为0.005~0.05 mg/kg；在0.04、0.08和0.32 mg/kg 3个添加水平下，102种农药的平均回收率为52 %~128%，RSD为1.0%~10 %。该方法快速简便、耗时短，具有良好的灵敏度、正确度和精密度，为提高当归中农药安全水平，降低健康风险提供了一种快速、高效、可靠的分析手段。     

高效液相色谱-串联质谱法检测稻田中吡嘧磺隆和苯噻酰草胺残留

采用高效液相色谱-串联质谱法(HPLC-MS/MS),建立了稻田水、土壤、水稻植株、稻秆、稻壳及糙米基质中吡嘧磺隆和苯噻酰草胺的残留分析方法。样品经20 m L V(乙腈)∶V(水)=70∶30的混合溶液提取,提取液用20 mg石墨化碳黑(GCB)与30 mg乙二氨基-N-丙基硅烷(PSA)净化,HPLC-M S/M S检测。吡嘧磺隆在上述各基质中的添加回收率在76%~107%之间,相对标准偏差(RSD)在1.5%~14%之间,定量限为0.004~0.01 mg/kg;苯噻酰草胺的添加回收率在77%~101%之间,RSD在2.4%~13%之间,定量限为0.001~0.01 mg/kg。实现了对两种除草剂同时简便、快速测定的要求。采用该方法测定了26%吡嘧磺隆·苯噻酰草胺水面扩展粒剂在稻田施用后,其有效成分吡嘧磺隆和苯噻酰草胺在实际样品中的残留量。结果表明,两种除草剂均属于易降解农药,在本试验条件下其在糙米中的残留量均低于我国最大残留限量(MRL)(吡嘧磺隆0.1 mg/kg;苯噻酰草胺0.05 mg/kg)。     

磁性分散固相萃取-QuEChERS结合气相色谱-串联质谱法检测不同柑橘基质中多种农药残留

基于磁性分散固相萃取 (MDSPE)-QuEChERS前处理技术，采用气相色谱-串联质谱法 (GC-MS/MS) 进行定性定量分析，建立了快速检测宽皮柑橘、甜橙、柠檬、柚子和金桔5种柑橘基质中75种农药残留的方法，优化了石墨化碳黑 (GCB)、N-丙基乙二胺 (PSA) 和磁性纳米粒子 (MNPS) 用量对不同柑橘中目标分析物回收率的影响。在优化条件下，目标分析物的线性范围在0.01~0.5 mg/kg之间，平均回收率为63%~118%，相对标准偏差为0.30%~16%。方法的检出限 (LOD) 为1~7 μg/kg，定量限 (LOQ) 为10~20 μg/kg。该方法简便、快速、安全、价格低廉，重现性良好，可用于不同柑橘中多种农药残留的快速确证检测。     

QuEChERS-气相色谱-质谱法测定粮谷中氰烯菌酯残留

建立了一种适用QuEChERS前处理结合气相色谱-质谱 (GC-MS) 技术测定4种粮谷（糙米、小麦、高粱及玉米）中氰烯菌酯残留的方法。样品经乙腈提取、PSA净化和浓缩后，采用GC-MS检测，内标法定量。结果表明:在10～500 μg/L质量浓度范围内，氰烯菌酯峰面积与进样质量浓度间线性关系良好，决定系数 (R2) > 0.9983，定量限 (LOQ) 低于0.005 mg/kg；在添加水平分别为0.005、0.02、0.05及0.1 mg/kg时，该方法的平均回收率在85%～108%之间，相对标准偏差 (RSDs) 为1.1%～10.4%。该方法简便、快速，具有良好的灵敏度和重现性，适用于粮谷中氰烯菌酯的残留量测定。     

分散固相萃取-超高效液相色谱-串联质谱法快速检测棉花和土壤中氟铃脲的残留

建立了分散固相萃取-超高效液相色谱-串联质谱快速检测棉花和土壤中氟铃脲残留的分析方法。样品采用乙腈提取,N-丙基乙二胺(PSA)净化,超高效液相色谱分离,电喷雾电离、负离子扫描,三重四级杆串联质谱检测以及基质匹配标准品的外标法定量。结果表明,在0.005~0.5 mg/kg 添加水平范围内,氟铃脲的平均添加回收率在71.1% ~110.0%之间,相对标准偏差在2.7% ~8.4%之间。该方法对土壤、棉叶和棉籽3种基质中氟铃脲的检出限 (LOD)分别为0.04,0.12,0.22 μ g/kg,定量限(LOQ)分别为0.14,0.41,0.74 μ g/kg。方法灵敏度高、操作简便、定量准确、测定浓度范围宽,可用于氟铃脲在棉叶、棉籽和土壤中的残留分析。     

高效液相色谱法检测环氧虫啶在柑橘及土壤中的残留

建立了环氧虫啶在柑橘和土壤中残留量测定的高效液相色谱(HPLC-UVD)分析方法。柑橘样品采用V(蒸馏水):V(二氯甲烷)=1:2提取后经弗罗里硅土柱净化(土壤样品提取后直接测定),HPLC-UVD测定,外标法定量,并运用此方法对田间样品进行了环氧虫啶残留量检测验证。结果表明:在0.05~5mg/L范围内,环氧虫啶质量浓度与对应的峰面积间呈良好线性关系,线性方程为y=10243x+233.0(R2=0.9990);土壤和柑橘中环氧虫啶的最低检测浓度均为0.1mg/kg;在0.1~1mg/kg3个添加水平下,环氧虫啶在土壤和柑橘中的平均回收率在76%~93%之间,相对标准偏差(RSD,n=5)在1.6%~5.8%之间。该方法快速、灵敏、稳定,可用于柑橘和土壤中环氧虫啶残留量的检测。     

多壁碳纳米管固相萃取气相色谱-串联质谱法测定乌龙茶及土壤中10种三嗪类除草剂残留

建立了乌龙茶及土壤中10种三嗪类除草剂(西玛津、莠去津、扑灭津、特丁津、敌草净、环丙津、西草净、莠灭净、扑草净和特丁净)残留的气相色谱-串联质谱(GC-MS/MS)分析方法。样品经乙腈提取后,以多壁碳纳米管(MWCNTs)、N-丙基乙二胺(PSA)、C18、MgSO4为净化剂分散净化后,在GC-MS/MS多反应监测(MRM)模式下进行测定,空白基质匹配标准曲线外标法定量。研究了不同提取溶剂、不同吸附剂种类及用量对提取净化效率的影响。结果表明:在各自质量浓度范围内(西草净和扑草净在10~500 μg/kg,其余8种除草剂在5~500 μg/kg)具有良好线性关系,相关系数(r)均大于0.99,10种三嗪类除草剂的定量限(LOQ)为5.0~10 μg/kg。在5~100 μg/kg添加水平下,10种三嗪类除草剂在乌龙茶和土壤中的平均回收率在75%~111%之间,相对标准偏差(RSD)在3.1%~8.7%(n=6)之间。该方法操作简单、净化效果好、灵敏度高,具有良好的适用性,能够满足乌龙茶及土壤中10种三嗪类除草剂残留分析测定的要求。     

Richtlinien der Verbände des ökologischen Landbaus zum Vorratsschutz

Zusammenfassung Verbände des ökologischen Landbaus wie z. B. Bioland, Gäa, Demeter; Naturland, Ernte für das Leben oder Bio Suisse beschränken ihre Mitglieder bei der Wahl von Vorratsschutzmaßnahmen. Vorrang besitzen Maßnahmen zur Vermeidung von Schädlingen gegenüber Bekämpfungsmaßnahmen. Fallen müssen zur Befallsüberwachung eingesetzt werden, um einen Befall durch Vorratsschädlinge frühzeitig zu erkennen. Diese Maßnahmen sollen den weitgehenden Verzicht auf chemisch-synthetische Mittel ermöglichen. In diesem Beitrag werden die Empfehlungen der Verbände mit den derzeit verfügbaren chemischen Mitteln für den Vorratsschutz abgeglichen. Erfahrung in der praktischen Umsetzung von physikalischen und biologischen Verfahren werden diskutiert und Defizite bei der Befallsüberwachung und Bekämpfung beschrieben.     

Hymenopteran Parasitoids on Fruit-infesting Tephritidae (Diptera) in Latin America and the Southern United States: Diversity, Distribution, Taxonomic Status and their use in Fruit Fly Biological Control

We first discuss the diversity of fruit fly (Diptera: Tephritidae) parasitoids (Hymenoptera) of the Neotropics. Even though the emphasis is on Anastrepha parasitoids, we also review all the information available on parasitoids attacking flies in the genera Ceratitis, Rhagoletis, Rhagoletotrypeta, Toxotrypana and Zonosemata. We center our analysis in parasitoid guilds, parasitoid assemblage size and fly host profiles. We also discuss distribution patterns and the taxonomic status of all known Anastrepha parasitoids. We follow by providing a historical overview of biological control of pestiferous tephritids in Latin American and Florida (U.S.A.) and by analyzing the success or failure of classical and augmentative biological control programs implemented to date in these regions. We also discuss the lack of success of introductions of exotic fruit fly parasitoids in various Latin American countries. We finish by discussing the most pressing needs related to fruit fly biological control (classical, augmentative, and conservation modalities) in areas of the Neotropics where fruit fly populations severely restrict the development of commercial fruit growing. We also address the need for much more intensive research on the bioecology of native fruit fly parasitoids.     

Development of protocols for detection of Colletotrichum acutatum and monitoring of strawberry anthracnose using real-time PCR

Real-time PCR (TaqMan®) assays were developed for the specific detection and discrimination of Colletotrichum spp., C. acutatum and C. gloeosporioides causing anthracnose in strawberry using the most divergent area of the internal transcribed spacers (ITS1 and ITS2) and 5·8S ribosomal RNA (rRNA) gene region. The specificity of the new assays was tested using DNA from six species of Colletotrichum and nine fungal species commonly found associated with strawberry material, and additionally by comparing the sequences with those from databases using a blast search. The sequences only showed identity with homologous sequences from the desired target organisms. The new assays were 10–100 times more sensitive than conventional PCR methods previously published for the diagnosis of strawberry anthracnose. When real-time PCR was compared with ELISA methods, PCR improved the sensitivity of the identification by obtaining positive results for samples of strawberry plant material that tested negative with ELISA. The development of C. acutatum was monitored using artificially infected strawberry crowns from two strawberry cultivars (Camarosa and Ventana) and a real-time PCR assay specific for this species between January and June 2006. The amount of C. acutatum detected using real-time PCR varied significantly by month ( P  < 0·001), but not by cultivar ( P  = 0·394). The new assays were shown to be useful tools for rapid detection and identification of these pathogens and to allow rapid and accurate assessment of the casual agents of anthracnose in strawberry.     

Brief Guide for Authors

正Journal of Arid Land(JAL)is an international journal(ISSN 1674-6767;CN 65-1278/K)for the natural sciences,sponsored by the Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences and Science Press.It is published by Science Press and Springer-Verlag Berlin Heidelberg bimonthly.JAL publishes original,innovative,and integrative research from arid and semiarid regions,ad     

The parasitoid complex ofLiriomyza cicerina on chickpea (Cicer arietinum)

Liriomyza cicerina (Diptera: Agromyzidae) is an important pest on chickpea in Turkey. The objective of this study was to determine the parasitoids and rates of parasitism ofL. cicerina on chickpea (Cicer arietinum L.) during the 2005 and 2006 seasons in ?anl?urfa province, Turkey. Leaves with mines were sampled weekly and kept in the laboratory to observe and count emerging leafminer and parasitoid adults. Eight parasitoid species were collected: the braconidsOpius monilicornis Fischer andOpius tersus Foerster and the eulophidsDiaulinopsis arenaria (Erdös) andNeochrysocharis formosa (Westwood), which occurred in both the winter and summer seasons;Diglyphus crassinervis Erdös,Neochrysocharis ambitiosa Hansson,Neochrysocharis sericea (Erdös) andPediobius metallicus (Nees), which occurred only in the summer growing areas.Diaulinopsis arenaria was the predominant parasitoid with 4–7.7% parasitism rate whileN. ambitiosa andO. monilicornis were the second and third most predominant species. The results of these trials show that sinceDia. arenaria occurred throughout every season, it could potentially be used for control of the leafminerL. cicerina.     

Plant–herbivore asynchrony necessitates augmentative releases of the exotic beetle,Zygogramma bicolorata,to enhance the biological control of P arthenium hysterophorus

Systematic information on the quantitative impact of Z ygogramma bicolorata on the biology of P arthenium hysterophorus is crucial as the seeds of this weed continue to germinate from the accumulated soil seed bank throughout the year in the form of different germinating flushes, while the activity of the beetle ceases during winter as it enters diapause. Therefore, plant–herbivore interactions need to be explored to develop predictions of the overall impact of the introduced beetle on the weed. The findings revealed that defoliation by Z . bicolorata had a significant impact on the plant height, density and flower production in flushes F ₃, F ₄ and F ₅, but not in F ₁ and F ₂ that exhibited longer periodicity, profuse branching, a longer flowering period and maximum flower production and contributed mostly to the existing seed soil bank. Therefore, total depletion of the existing soil seed bank was not possible. Consequently, the effect of augmentative field releases of laboratory‐reared beetles was explored on F ₁ and F ₂ in February for three consecutive years (2011–2013). Before initiating the trial, random soil samples were taken from the plots that were assigned to the paired treatments (i.e. with the beetle and without the beetle [insecticide‐treated]) and it was found that the seed bank in those samples did not differ. The single release of Z . bicolorata adults at five per plant at the six‐leaf stage significantly reduced the soil seed bank, compared to without the biocontrol agent, irrespective of the flushes at the end of the season.     

Effects of the saprophytic leaf mycoflora on growth and productivity of winter wheat

The effects of the saprophytic mycoflora and its interference with cereal aphids on growth and yield of winter and spring wheat was studied in field experiments in 1980, 1981 and 1982.Yields varied between 5000 and 8000 kg dry matter of kernels per ha. The effect of the saprophytic mycoflora on yield was determined in different treatments: A) no control measures against cereal aphids and saprophytic and necrotrophic fungi, B) no control of cereal aphids, control of saprophytic and necrotrophic fungi, C) control of cereal aphids and control of saprophytic and necrotrophic fungi, D) control of cereal aphids and stimulation of saprophytic mycoflora and E) control of cereal aphids, no control of saprophytic and necrotrophic fungi nor stimulation of saprophytic mycoflora.Considerable differences in top densities of saprophytic mycoflora (10 times as large in A and D as in B and C) were determined. The consequences of these differences for the growth and productivity of wheat were minor. A negative effect of saprophytic mycoflora on the yield could not be detected in 1981 and 1982, whereas a small positive significant effect was found in 1980. This stimulation may have been due to competition between necrotrophic fungal pathogens and saprophytic mycoflora. As a result of favourable weather conditions necrotrophic fungal pathogens were very numerous in 1980 and could form an important yield reducing factor. Yield levels may effect the importance of the necrotrophic and saprophytic mycoflora as yield reducing factors. Additionally, in the presence of aphid honeydew captafol was found to be relatively ineffective against saprophytic fungi.