西藏飞蝗研究进展

西藏飞蝗Locusta migratoria tibetensis是为害小麦Triticum aestivum、青稞Hordeum vulgare等禾本科作物及牧草的重要高原害虫,具有发生面积大、繁殖能力强和为害重等特点,在西藏自治区雅鲁藏布江沿岸、青海省玉树藏族自治州和四川省甘孜藏族自治州等地均有过多次暴发的历史记录,给当地农牧业造成了严重的经济损失。为全面了解西藏飞蝗的发生规律及其相关研究进展,本文主要综述了西藏飞蝗的地理分布、形态学特征、生物学特性、生态学特征和防治措施等内容,同时对西藏飞蝗未来的研究方向以及综合防控进行了展望。     

6种杀虫剂对苹果园苹褐带卷蛾的田间防效

为了阐明茶刺蛾（Iragoides fasciata Moore)幼虫的取食为害及生长发育特征,明确其防治适期和防治指标。通过室内饲养观察,测定了茶刺蛾各龄幼虫的取食量、体长、体宽及体重,按防治后挽回的损失与防治成本相等的方法估算了其在有机茶园的防治指标。结果表明整个幼虫期取食茶叶1.547 g/头,其中1~3龄的取食量极小,从4龄开始取食量逐渐增大,6、7龄的取食量分别占总取食量的19%和71.4%。幼虫体重随龄期增加而增长的趋势与取食量一致,从4龄起开始快速增长,至7龄时达到最高值0.167 g。为防止茶刺蛾暴发为害,应在取食量小的4龄前开展防治。有机茶园防治指标拟定为6头/m2。     

西藏雅鲁藏布江中下游飞蝗发生频繁

据西藏自治区农业科学研究所王成明同志来信称,近几年西藏地区飞蝗频繁发生。1963年中国科学院动物研究所陈永林研究员将西藏发生的飞蝗定名为“西藏飞蝗”Locusta mi-gratoria tibensis Chen。近年来发生数量呈上升趋势,特别是雅鲁藏布江中、下游地区虫口密度较高,多次造成严重危害。1988年6月19日,米林县差纳区暴发大面积飞蝗,王成明目睹成群蝗蝻和成虫,从空中和水面横跨雅鲁藏布江,蝗群迁移危害青稞、冬小麦,甚至苜蓿,经县领导发动组织全县人民,齐心协力及时扑打,但仍有1000多亩小麦、青稞和少量     

3种生物农药对西藏飞蝗的防治效果

西藏飞蝗是川西北草原主要的生物灾害之一,近年来平均危害面积在7.5万hm2左右,且呈现出逐年加重趋势。为加大对西藏飞蝗的防治力度,试验应用瑞·苏生防剂、2%阿维·苏云菌可湿性粉剂、1%苦参碱可溶液剂3种生物农药分别对西藏飞蝗进行小区和大面积防治试验,比较3种生物药剂的防治效果。结果表明,3种生物农药对西藏飞蝗的小区试验防治效果在89.99%~92.12%之间,大面积防治效果在86.50%~92.41%之间,均具有较高的防效,可作为防治川西草原西藏飞蝗的选用药剂。     

不同龄期及密度亚洲小车蝗取食对牧草产量的影响

采用田间罩笼和人工模拟取食两种方式,分别测定了亚洲小车蝗1～3龄、4龄、5龄和成虫在虫口密度5、15、30头/m²下取食牧草对草地产草量的影响。结果表明:低龄期蝗虫取食对牧草有明显的超补偿生长作用,产草量增加,罩笼试验产草量高于模拟取食试验;随亚洲小车蝗龄期增加,取食量加大,草地产草量迅速下降,成虫期产草量最低。罩笼方法与模拟方法结合能真实地反应蝗虫取食与草地产草量的相互关系。     

轮纹异痂蝗生物学特性初步研究

研究结果表明:轮纹异痂蝗在通辽1年发生1代,以卵在土中越冬。越冬卵于翌年5月上中旬孵化,蝗蝻共4龄,全蝻期26～32 d,6月上、中旬为羽化盛期。7月上、中旬为产卵盛期,卵产在土中深4～6 cm处。成虫可活到9月中旬。轮纹异痂蝗喜食菊科和百合科等幼嫩多汁的植物,食量为每头每日食鲜草1.05 g,每666.7 m²可损失鲜草10.25～12.75 kg。     

温度对四川省甘孜州西藏飞蝗分布的影响

温度是西藏飞蝗分布的主要限制性因子,作者通过试验测定了四川省甘孜州西藏飞蝗各种虫态的过冷却点、发育起点温度及有效积温。该虫初产卵的过冷却点为-24.4℃,孵化前为-20.7℃,是耐寒性最强的虫态,1～5龄蝻、雌、雄成虫过冷却点分别为-9.28、-8.51、-7.18、-6.64、-8.07、-7.86、-7.96℃。卵、1～5龄蝻、全世代的发育起点温度分别为14.17、15.84、16.64、16.80、16.35、15.00、14.61℃,有效积温分别为179.14、67.53、61.07、62.09、71.16、91.20、787.78日度,卵到蝗蝻的有效积温为540.2日度。统计气象资料表明,夏季高温不是西藏飞蝗限制因素,甘孜州石渠、色达、理塘的冬季低温影响西藏飞蝗的安全越冬,在甘孜州其他县可以越冬,并可发生1代。作者在乡城县观测圃饲养西藏飞蝗能成功越冬,年发生1代,其发育进度与有效积温分析一致。     

关于东亚飞蝗防治适期的商榷

20世纪 90年代以来 ,由于受异常气候、农业生态环境及白洋淀水位变化等因素的影响 ,东亚飞蝗在河北省白洋淀蝗区出现了 1993、1995、1998、1999年和 2 0 0 1年持续大发生。 195 2年邱式邦等先生在毒饵治蝗方法一文中提出“将蝗虫消灭在 3龄以前” ;195 7年农业部在冀、鲁、豫、苏、皖 5省及天津市治蝗座谈会总结一文中 ,提出“力求做到在 3龄以前 ,一次喷药消灭秋蝗主力” ;196 3年郭尔溥先生在飞机喷粉防治东亚飞蝗的药量问题一文中 ,提出“应抓住蝗蝻 3龄以前的防治是十分必要的。”当前 ,由于环境及气候条件的变化使蝗蝻出土期延长、飞机…     

温度对安婀珍蝶取食量的影响

安婀珍蝶Actinote anteas(Doubleday&Hewitson)作为控制害草薇甘菊Mikania micrantha的生物防治因子,在14～26℃范围内,在相同温度不同龄期的取食量变化规律相同.1～4龄幼虫之间,幼虫的取食量变化不大,但在4龄以后,幼虫的取食量成倍增长.不同温度下安婀珍蝶幼虫各龄期取食量随温度的升高而增大;1、3、5、6龄幼虫的取食量在23℃时达最高,在26℃时有所回落;幼虫期的总取食量在14～26℃范围内,取食量随温度的升高而增大;14～17℃之间,取食量增加较快,在17℃以后,取食量增加缓慢.通过分析建立安婀珍蝶幼虫日平均取食量与温度间的回归模型Y=-60.054+8.788X-0.402X2+0.006X3,P＜0.05,R2=0.9989,对模型进行计算得出安婀珍蝶取食量最适温度为25.58℃.     

草原蝗虫防治指标的研究

作者测定了4种蝗虫从孵化至成虫期的食量,把草原蝗虫划分为以红翅皱膝蝗、邱氏异爪蝗和狭翅雏蝗为代表的大、中、小三种食量类型,混合种群虫口密度(x)与其对牧草取食量(y)的模型为y=16.4732x。通过野外混合种群不同密度下对牧草产量损失的测定,回归式为(ŷ)=-20.8070+14.4143x±15.56(r=0.9993,F>F_0.01),两种方法计算的防治指标分别为21.7、26.2头/m²,其经济允许损失均为8.8%。大、中、小三种食料类型的防治指标分别为5.2、17.6和32.3头/m²。     

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.     

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.     

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.     

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.     

The autumn leafroller: Phenology,damage and parasitoids in a Dutch apple orchard

The phenology of the autumn leafroller,Syndemis musculana, a local pest of apple, was studied in order to forecast larval emergence. From 1983–1986, peak flight as determined with sexpheromone traps was always between 13–18 May. The duration of embryonic development was determined at various constant temperatures and used to estimate the periods of egg hatch in these four years. Each year, most eggs should have hatched in the second decade of June.Differences in attack rates between apple cultivars seem to be explained largely by the variation in picking time. Larvae are only half grown at the beginning of harvest (cv. James Grieve), and have gone into hibernation when the latest variety (cv. Golden Delicious) is picked. Moreover, the varieties Cox's Orange Pippin and Belle de Boskoop, picked about half time, are liable to receive additional damage by caterpillars brought with the picked fruits into storage.Various hymenopterous parasites were reared from caterpillars. As the only leafroller in the orchard which hibernates as mature larva,S. musculana may promote winter survival of some parasitoids, like the eulophidColpyclypeus florus.Samenvatting De fenologie van de herfstbladroller (Syndemis musculana Hübner), een incidentele plaag op appel, werd nader bepaald met het doel het uitkomen van de eieren te kunnen voorspellen. In 1983–1986 viel de piekvlucht, bepaald met behulp van feromoonvallen, steeds tussen 13 en 18 mei.De ontwikkelingsduur van de eieren bij verschillende constante temperaturen werd gebruikt om de periode van uitkomen te schatten. De meeste eieren zullen ieder jaar in de eerste helft van juni uitkomen.Geconstateerde verschillen in schade tussen appelrassen blijken goeddeels terug te voeren op verschillen in pluktijdstip. De rupsen van de herfstbladroller zijn pas half-was als de eerste appels eind augustus geplukt worden, terwijl tegen het einde van de oogst begin oktober de meeste al in winterslaap zijn. Met name tussentijdse rassen, als Cox's Orange Pippin and Schone van Boskoop, lopen extra schade op doordat grotere rupsen met de geplukte vruchten in de kist terecht komen.Uit de rupsen werden negen, al van andere boomgaardbladrollers bekende, sluipwespen gekweekt, Omdat deze bladrollersoort, als enige in de boomgaard, als volgroeide rups overwintert, lijkt zij bij uitstek geschikt als winterwaard.This study was carried out at the Experimental Orchard De Schuilenburg, Schuilenburg 3, 4041 BK Kesteren, the Netherlands, to which address correspondence should be addressed.     

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.     

Characterization of Sclerotinia minor populations in Texas peanut fields

In the summer of 2004 an epidemic of sclerotinia blight of peanut, a disease caused by Sclerotinia minor, occurred in Texas in fields where the disease was never previously detected. The disease was observed on many plants within one of the fields (>3000 disease foci), although most foci were <1 m. It is hypothesized that these observations were inconsistent with the recent introduction of a monocyclic pathogen, even if disease developed under conducive environmental conditions. The pattern of disease is most suggestive of the presence of foliar (ascospore) infections, although air temperature was above the known limits for apothecia development if the pathogen had arrived in the field in 2004 peanut seed. To further examine this epidemic, 232 isolates were collected, across a variety of spatial scales spanning this field and other Texas peanut fields, and evaluated for aggressiveness, fungicide sensitivity and genotypic diversity. There was wide variation among isolates for the phenotypic characteristics measured, but there was no evidence that a genotypically unique, highly aggressive, and fungicide resistant isolate had been introduced or evolved. The predominant genotype, TX1, which contained 154 isolates, was found in every county and field population.     

Eyespot of Cereals Revisited: ITS phylogeny Reveals New Species Relationships

Four species so far classified in Pseudocercosporella or Ramulispora (hyphomycetes) are associated with eyespot disease symptoms of cereals. Two of these have been linked to teleomorphs that were described in Tapesia. Sequence data derived from the Internal Transcribed Spacer region (ITS1, 5.8S and ITS2) of the rDNA operon showed, however, that the eyespot fungi associated with Tapesia are not congeneric with Ramulispora sorghi, the type of Ramulispora. The genus name Tapesia is now rejected in favour of the conserved name Mollisia, which appears to comprise heterogeneous fungi. Tapesia yallundae is not closely related to the type of Mollisia, M. cinerea, but clusters separately, being more closely allied to species with Cadophora anamorphs. A new holomorph genus, Oculimacula, is therefore proposed for teleomorphs of the eyespot fungi, while the anamorphs are accommodated in Helgardia gen. nov.