新烟碱类杀虫剂的作用机制、应用及结构改造的研究进展

新烟碱类杀虫剂具有高效、低毒、广谱、选择毒性强和对环境安全等现代提倡的有机农药特点,是目前常用的最佳杀虫剂品种之一。本文结合最新进展,介绍了新烟碱类杀虫剂及其受体的结构特点、作用机制、应用及新烟碱类杀虫剂化合物分子结构改造等方面的研究。     

新烟碱类杀虫剂选择作用的分子机理

新烟碱类是一类重要的新颖杀虫剂,其发现是近20年来杀虫剂研究的一个里程碑。烟碱类和新烟碱类杀虫剂虽然都是作为后突触烟碱乙酰胆碱受体(nAChRs)的激动剂作用于昆虫的神经系统,但由于作用方式不同,新烟碱类杀虫剂对昆虫表现出选择性毒性。根据烟碱类和新烟碱类杀虫剂结构与活性的关系、分子特性以及它们与nAChR的结合部位和亚部位的选择性阐释了新烟碱类杀虫剂选择作用的分子机理。     

欧盟新烟碱类农药限用政策对我国农药相关产业的风险分析

欧盟宣布从2013年7月1日起对新烟碱类农药实施限用政策,以降低或避免对蜜蜂的种群危害。根据欧盟的这一法规,新烟碱类杀虫剂除冬播麦类外几乎不能在其它大田、露地作物上使用,首批涉及农药品种有吡虫啉、噻虫嗪和噻虫胺3个品种。新烟碱类农药是我国目前使用在蔬菜水果和粮食作物上的最广泛的杀虫剂品种,也是我国农药出口创汇的主打品种,欧盟新烟碱类农药管理政策的变化,势必将对我国农药生产、使用以及农产品贸易带来较大影响。本文详细阐述了欧盟新烟碱类农药限用政策背景、我国新烟碱类农药登记使用情况以及新烟碱类农药管理政策调整对我国可能产生的影响和应对措施。通过对限用新烟碱类农药进行风险分析,以期减少或降低该政策对我国农药相关产业的负面影响。     

害虫对新烟碱类杀虫剂的抗药性及其治理策略

烟碱和新烟碱类杀虫剂都是作为后突触烟碱乙酰胆碱受体(nAChRs)的激动剂作用于昆虫中枢神经系统,但这两类杀虫剂存在明显不同的选择毒性:烟碱类对哺乳动物毒性较高,而杀虫活性低;新烟碱类具有高杀虫活性,而对哺乳动物低毒。由于新烟碱类杀虫剂的作用方式独特,对以前使用的如拟除虫菊酯类、氯化烃类、有机磷类和氨基甲酸酯类等杀虫剂很少或无交互抗性,该类杀虫剂为防治一些世界性重大害虫(包括对以前使用的杀虫剂具有长期抗性的害虫)作出了重要贡献。但现已发现不少害虫对新烟碱类杀虫剂产生了抗性。文章就害虫对新烟碱类杀虫剂的抗性概况、抗性机理和抗性治理策略进行了综述。     

新烟碱类杀虫剂登记与管理现状分析

新烟碱类杀虫剂已成为全球使用最广泛和增长最快的杀虫剂类型。本文介绍了对新烟碱类杀虫剂在我国、美国、欧盟、加拿大和澳大利亚登记和管理现状,提出了新烟碱类杀虫剂的风险-效益分析方面的建议。     

新烟碱类杀虫剂及稠环固定的顺式衍生物研究进展

新烟碱类杀虫剂是第四大类重要的杀虫剂,主要作用于昆虫的烟碱乙酰胆碱受体(nAChRs)。概述分析了新烟碱类杀虫剂的结构特征、作用机制及其构型,综述了近5年来新烟碱类杀虫剂的研究进展,并在比较分析的基础上,阶段性总结了作者近年来在稠环固定的顺式衍生物方面的研究工作。     

新烟碱类杀虫剂对蜜蜂亚致死效应的研究进展

蜜蜂是一种经济型昆虫,其授粉作用在农业生产、濒临植物保护等方面具有重要意义。新烟碱类杀虫剂的广谱性、高效性、对哺乳动作的低毒性使得这类药剂备受人们关注,被广泛使用在农业生产生活中。近年来,新烟碱类杀虫剂对蜜蜂的潜在威胁也成为研究的热点,特别是对蜜蜂亚致死效应的研究。本文简要介绍了新烟碱类杀虫剂的应用概况及其作用机理,重点阐述了亚致死剂量的新烟碱类杀虫剂对蜜蜂生长发育及行为等的影响,并提出了几个有待进一步研究解决的问题,以期为我国新烟碱类杀虫剂对蜜蜂的安全性评价工作提供参考信息。     

新烟碱类杀虫剂亚致死剂量对麦长管蚜和棉蚜取食行为的影响

为了明确新烟碱类杀虫剂亚致死剂量对麦长管蚜和棉蚜拒食作用的差异,通过铷标记法、蜜露法以及两种蚜虫体内总糖、总脂含量的测定研究了新烟碱类杀虫剂亚致死剂量对麦长管蚜和棉蚜取食的影响。结果表明,铷标记法和蜜露法测定的新烟碱类杀虫剂亚致死剂量对麦长管蚜的拒食率均在80%以上,而对棉蚜的拒食率均在25%以下。蚜虫体内总糖总脂含量测定结果表明,新烟碱类杀虫剂亚致死剂量处理后麦长管蚜体内总糖、总脂含量均显著低于对照,而棉蚜体内总糖、总脂含量与对照均无显著差异。三种方法测定结果一致表明新烟碱类杀虫剂亚致死剂量对麦长管蚜具有很强的拒食作用,而对棉蚜没有明显的拒食作用。     

棉蚜对新烟碱类杀虫剂的抗性现状及其治理策略

棉蚜Aphis gossypii Glover是棉花生产中最严重的害虫之一。长期以来防治棉蚜主要依赖于化学杀虫剂,其中新烟碱类杀虫剂扮演着十分重要的角色,但由于其长期、大量的使用,棉蚜已对该类杀虫剂产生了较高水平的抗性,严重影响了对棉蚜的防治效果。抗性机制研究表明,棉蚜对新烟碱类杀虫剂产生抗性的机制主要涉及解毒代谢能力增强和靶标敏感性下降。细胞色素P450、羧酸酯酶、谷胱甘肽S-转移酶、UDP-葡糖基转移酶等解毒酶基因过量表达介导的解毒代谢增强和烟碱型乙酰胆碱受体β1亚基突变引起的靶标敏感性下降是棉蚜对新烟碱类杀虫剂产生抗性的关键。针对我国棉蚜对新烟碱类杀虫剂抗性问题突出的现状,为更好地利用该类药剂防治棉蚜,亟需根据棉蚜抗性机制制定合理的抗性治理策略。本文将从棉蚜对新烟碱类杀虫剂的抗性现状、抗性机制以及抗性治理策略等方面进行综述,以期为抗性棉蚜的科学治理提供参考。     

先正达/拜耳建言欧盟新烟碱类杀虫剂计划

为推动破解欧盟有关新烟碱类杀虫剂对蜜蜂健康"理论风险"僵局,先正达和拜耳提出一份行动计划建议。此举是在欧盟委员会就其一项有关2年内禁止在某些作物上使用噻虫胺、吡虫啉和噻虫嗪等新烟碱类杀虫剂     

Dermestid beetles in ‘evolution Canyon’, lower Nahal Oren, Mt. Carmel, including new records for Israel

Fifteen species of dermestid beetles were recorded at ‘Evolution Canyon’ (EC), Lower Nahal Oren, Mt. Carmel, Israel. They represent ~35% of known Israeli dermestid species. The following three species were recorded for the first time in Israel:Trogoderma svriaca Dalla Torre, 1911;Ctesias svriaca Ganglbauer, 1904; andAnthrenus (s.str.) jordaniens Pic, 1934. Adults of 13 species were collected on the more solar radiated, warmer and climatically more fluctuating south-facing slope (SFS); ten species were collected on the opposite, north-facing slope (NFS), which was cooler and climatically more stable. The abundance of adult dermestid beetles was 1.9 times higher on the SFS than on the NFS (86 and 47, respectively). Species richness and abundance distribution at EC (three collecting stations on each slope and one at the valley bottom) were significantly negatively correlated with the plant cover that consisted of trees and bushes (Spearmanr _s ,P=0.007 and 0.039, respectively) and perennials (Spearmanr _s ,P=0.039 and 0.077, respectively), indicating that non-woody plants were preferred by adult dermestid beetles.     

Diagnostics,genetic diversity and pathogenic variation of ascochyta blight of cool season food and feed legumes

Molecular diagnostic techniques have been developed to differentiate the Ascochyta pathogens that infect cool season food and feed legumes, as well as to improve the sensitivity of detecting latent infection in plant tissues. A seed sampling technique was developed to detect a 1% level of infection by Ascochyta rabiei in commercial chickpea seed. The Ascochyta pathogens were shown to be genetically diverse in countries where the pathogen and host have coexisted for a long time. However, where the pathogen was recently introduced, such as A. rabiei to Australia, the level of diversity remained relatively low, even as the pathogen spread to all chickpea-growing areas. Pathogenic variability of A. rabiei and Ascochyta pinodes pathogens in chickpea and field pea respectively, appears to be quantitative, where measures of disease severity were based on aggressiveness (quantitative level of infection) rather than on true qualitative virulence. In contrast, qualitative differences in pathogenicity in lentil and faba bean genotypes indicated the existence of pathotypes of Ascochyta lentis and Ascochyta fabae. Therefore, reports of pathotype discrimination based on quantitative differences in pathogenicity in a set of specific genotypes is questionable for several of the ascochyta-legume pathosystems such as A. rabiei and A. pinodes. This is not surprising since host resistance to these pathogens has been reported to be mainly quantitative, making it difficult for the pathogen to overcome specific resistance genes and form pathotypes. For robust pathogenicity assessment, there needs to be consistency in selection of differential host genotypes, screening conditions and disease evaluation techniques for each of the Ascochyta sp. in legume-growing countries throughout the world. Nevertheless, knowledge of pathotype diversity and aggressiveness within populations is important in the selection of resistant genotypes.     

Epidemiology of Toxigenic Fungi and their Associated Mycotoxins for Some Mediterranean Crops

Recent data on the epidemiology of the common mycotoxigenic species of Fusarium, Alternaria, Aspergillus and Penicillium in infected or colonized plants, and in stored or processed plant products from the Mediterranean area are reviewed. Emphasis is placed on the toxigenicity of the causal fungal species and the natural occurrence of well known mycotoxins (aflatoxins, ochratoxins, fumonisins, trichothecenes, zearalenone, patulin, Alternaria-toxins and moniliformin), as well as some more recently described compounds (fusaproliferin, beauvericin) whose toxigenic potential is not yet well understood. Several Fusarium species reported from throughout the Mediterranean area are responsible of the formation of mycotoxins in infected plants and in plant products, including: Fusarium graminearum, F. culmorum, F. cerealis, F. avenaceum, F. sporotrichioides and F. poae, which produce deoxynivalenol, nivalenol, fusarenone, zearalenone, moniliformin, and T-2 toxin derivatives in wheat and other small grains affected by head blight or scab, and in maize affected by red ear rot. Moreover, strains of F. verticillioides, F. proliferatum, and F. subglutinans, that form fumonisins, beauvericin, fusaproliferin, and moniliformin, are commonly associated with maize affected by ear rot. Fumonisins, were also associated with Fusarium crown and root rot of asparagus and Fusarium endosepsis of figs, caused primarily by F. proliferatum. Toxigenic A. alternata strains and associated tenuazonic acid and alternariols were commonly found in black mould of tomato, black rot of olive and citrus, black point of small cereals, and black mould of several vegetables. Toxigenic strains of A. carbonarius and ochratoxin A were often found associated with black rot of grapes, whereas toxigenic strains of A. flavus and/or P. verrucosum, forming aflatoxins and ochratoxin A, respectively, were found in moulded plant products from small cereals, peanuts, figs, pea, oilseed rape, sunflower seeds, sesame seeds, pistachios, and almonds. Finally, toxigenic strains of P. expansum and patulin were frequently found in apple, pear and other fresh fruits affected by blue mould rot, as well as in derived juices and jams.     

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.     

A survey of the genera of<Emphasis Type="Italic">Microgaster</Emphasis> latreille and<Emphasis Type="Italic">Hygroplitis</Emphasis> thomson (Hymenoptera: Braconidae: Microgastrinae) from China

The genera ofMicrogaster Latreille 1804 andHygroplitis Thomson 1895 from China are presented systematically in this paper. Thirty-two species ofMicrogaster and three species ofHygroplitis are known in China. Diagnosis, character variation, distribution and host of each species among the two genera are presented, including its host and distribution. Keys to the species ofMicrogaster andHygroplitis are given. http://www.phytoparasitica.org posting Dec. 19, 2006.     

Plant Viruses Transmitted by Whiteflies

One-hundred and fourteen virus species are transmitted by whiteflies (family Aleyrodidae). Bemisia tabaci transmits 111 of these species while Trialeurodes vaporariorum and T. abutilonia transmit three species each. B. tabaci and T. vaporariorum are present in the European–Mediterranean region, though the former is restricted in its distribution. Of the whitefly-transmitted virus species, 90% belong to the Begomovirus genus, 6% to the Crinivirus genus and the remaining 4% are in the Closterovirus, Ipomovirus or Carlavirus genera. Other named, whitefly-transmitted viruses that have not yet been ranked as species are also documented. The names, abbreviations and synonyms of the whitefly-transmitted viruses are presented in tabulated form together with details of their whitefly vectors, natural hosts and distribution. Entries are also annotated with references. Whitefly-transmitted viruses affecting plants in the European–Mediterranean region have been highlighted in the text.     

The use of Solacol® (validamycin) as a growth retardant in the isolation of soil fungi

Solacol^®, a formulation of the antibiotic validamycin, at 0.33% in 2% malt extract agar, reduced the spread of fungi on dilution plates drastically and allowed twice as much incubation time before subculturing; this resulted in an elevated number of species isolated. Using pure cultures of 62 common soil fungi, it was shown that all fast-growing species (exceptPythium ultimum) were efficiently inhibited but not completely suppressed. Inhibition was comparable to that by 0.5% oxgall, though, while this substance completely suppressed several species, Solacol very strongly inhibited onlyGaeumannomyces graminis, Gerlachia nivalis, Harzia acremonioides, Verticillium biguttatum andRhizoctonia solani. In a further experiment each separate constituent of Solacol was tested against 22 fungi at equivalent concentrations. Validamycin strongly inhibitedChaetomium globosum and two Basidiomycetes, though hardly more than the non-ionic detergent which mainly inhibited the other fungi. A few species were, however, more inhibited by Solacol than by the detergent alone. Solacol at 0.33% is a suitable aid in dilution plating of soil fungi, by increasing the number of colonies and species observed.Samenvatting Solacol^®, een formulering van het antibioticum validamycine, remde de groei van schimmels in verdunningsplaten met een concentratie van 0.33% in 2% moutagar en maakte het mogelijk de periode tot afenten met een factor 2 te verlengen; daardoor was het aantal geïsoleerde soorten duidelijk toegenomen. Met reincultures van 62 algemene grondschimmelsoorten werd aangetoond, dat alle snelgroeiende soorten (met uitzondering vanPythium ultimum) voldoende geremd, maar niet volkomen onderdrukt werden. Het remmingspercentage was vergelijkbaar met dat van 0.5% ossegal, hoewel dit laatste sommige soorten volkomen onderdrukte; Solacol remde alleenGaeumannomyces graminis, Gerlachia nivalis, Harzia acremonioides, Verticillium biguttatum enRhizoctonia solani zeer sterk. In een volgend experiment werden de componenten van Solacol t.o.v. 22 fungi apart getoetst in concentraties equivalent aan 0.33% Solacol. Validamycine remde alleenChaetomium globosum en twee basidiomyceten behoorlijk, maar nauwelijks meer dan de niet-ionische uitvloeier, die in hoofdzaak de overige remeffecten veroorzaakte. Enkele soorten werden echter door het complete Solacol veel sterker geremd dan door de uitvloeier alleen. Solacol in een verdunning van 0,33% wordt aanbevolen bij verdunningsplaten voor het isoleren van grondschimmels ten einde het aantal kolonies en soorten te verhogen.     

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     

Broad bean mottle virus in Morocco; curculionid vectors,and natural occurrence in food legumes other than faba bean (Vicia faba)

Broad bean mottle virus (BBMV) was transmitted from infected to healthy faba-bean plants by the curculionid weevilsApion radiolus Kirby,Hypera variabilis Herbst,Pachytychius strumarius Gyll,Smicronyx cyaneus Gyll, andSitona lineatus L. The latter appeared to be an efficient vector: acquisition and inoculation occurred at the first bite, the rate of transmission was c. 41%, and virus retention lasted for at least seven days.S. lineatus transmitted the virus from faba bean to lentil and pea, but not to the three genotypes of chickpea tested. This is the first report on the generaHypera, Pachytychius, andSmicronyx as virus vectors, and onA. radiolus, H. variabilis, P. strumarius, andS. cyaneus as vectors of BBMV.Out of 351 samples of food legumes with symptoms suggestive of virus infection, 16, 11, 19, and 17% of the samples of chickpea, lentil, pea, and common bean, respectively, were found infected when tested for BBMV in DAS-ELISA. This is the first report on the natural occurrence of BBMV in chickpea, lentil, pea, and common bean. The virus should be regarded as a food-legume virus rather than a faba-bean virus solely, and is considered an actual threat to food legume improvement programmes.     

Characterization of potato potyvirus Y (PVY) isolates from seed potato batches. Situation of the NTN, Wilga and Z isolates

A collection of 38 PVY isolates from seed potato batches, originating from several Western European countries, was characterized by using current biological, serological and molecular tools differentiating PVY strains and groups. The correlation between the three kinds of tests was good but not absolute. No single serological or PCR method was able to discriminate among the five isolate groups found. Twenty-nine isolates belonged to the PVY^N strain and six to the PVY^O strain. No PVY^C was found. Two other isolates reacted serologically like PVY^O, but were unable to elicit a hypersensitive response from the Ny_tbr gene and probably represent the PVY^Z group. At the molecular level, these two isolates showed a combination of both PVY^O and PVY^N and could be recombinants of these strains. Another isolate reacted serologically like PVY^O, but induced vein necrosis in tobacco, like PVY^N-Wilga. Some PVY^N isolates caused tuber ring necrosis in glasshouse conditions. These might belong to the PVY^NTN group. The PVY^NTN, PVY^N-Wilga and PVY^Z groups probably represent pathotypes within strains PVY^N and PVY^O, respectively. The present study also confirms previous reports showing a high genetic variation at the 5 end within the PVYN strain.