玉米螟赤眼蜂适宜生境的研究与利用:Ⅲ.夏玉米间作匍匐型绿豆对赤眼蜂的增诱作用及其在穗期玉米螟防治中的利用

本文就夏玉米间作匍匐型绿豆对玉米螟赤眼蜂增诱作用及其在穗期玉米螟防治中利用的可行性进行了研究。结果表明，夏玉米间作匍匐型绿豆结合接种式放蜂区，与平作夏玉米结合接种式放蜂区和不放蜂对照区相比，明显提高了玉米螟赤眼蜂对螟卵的寄生率，１９９２年三者人工挂卵的卵块总寄生率分别为２６．７％、３．６％和０；１９９３年分别为２８．０％、６．６％和１．０％，自然落卵的寄生率分别为６９．１％、２２．４％和４．６％。１９９４年用心叶期抗螟品种间作绿豆结合接种式放蜂区，人工挂卵的卵块总寄生率为３０．７％，而平作夏玉米不放蜂对照区仅为２．５％；自然落卵的卵块寄生率前者为５６．２％，后者为１２．３％。心叶期抗螟品种间作匍匐型绿豆结合接种式放蜂区、心叶期抗螟夏玉米平作不放蜂和感螟品种不放蜂对照区的平均百株蛀孔数分别为５４．８、１０２．６和２７７．２个，放蜂区与两个不放蜂对照区相比，对玉米螟的防效分别为４６．６％和８０．２％。试验结果显示采用心叶期玉米抗螟品种间作匍匐型绿豆，并接种释放少量赤眼蜂等综合措施对穗期玉米螟害有明显的控制作用     

利用松毛虫赤眼蜂共寄生柞蚕卵繁育玉米螟赤眼蜂

为明确玉米螟赤眼蜂Trichogramma ostriniae Pang et Chen与松毛虫赤眼蜂T. dendrolimi Matsumura共寄生柞蚕Antheraea pernyi(Guérin-Méneville)卵后能否借助松毛虫赤眼蜂在柞蚕卵上的羽化孔顺利出蜂,在不同温度(20、23、26、29、32℃)、相对湿度(50%、60%、70%、80%、90%)以及光照周期(L∶D=24∶0、19∶5、14∶10、10∶14、5∶19、0∶24)条件下对这2种赤眼蜂共寄生柞蚕卵的各项生物学参数进行了比较分析。结果表明:利用松毛虫赤眼蜂与玉米螟赤眼蜂共寄生柞蚕卵可以提高玉米螟赤眼蜂的羽化率,在温度为26℃时,2种赤眼蜂对柞蚕卵的寄生率达90.0%,羽化率达96.8%,单卵玉米螟赤眼蜂出蜂数达到最高,为3.8头;相对湿度为80%时,2种赤眼蜂对柞蚕卵的寄生率达83.3%,羽化率达92.0%,单卵玉米螟赤眼蜂出蜂数达到最高,为6.5头;光照条件为L 24 h:D 0 h时,2种赤眼蜂对柞蚕卵的寄生率达93.3%,羽化率达96.4%,单卵玉米螟赤眼蜂出蜂数达到最高,为6.9头。表明利用松毛虫赤眼蜂和玉米螟赤眼蜂共寄生柞蚕卵的方法可以实现柞蚕卵正常繁育玉米螟赤眼蜂。     

亚洲玉米螟一、二代成虫扩散规律研究

１９９１－１９９２年在河北省衡水市亚洲玉米螟一、二代成虫盛发期，在田间释放用人工饲养、苏丹蓝Ⅱ标记的玉米螟成虫３４万头，在距释放点１、２、４、６、８、１０、２０、３０、４０、５０ｋｍ处设点回收，以研究玉米螟田间扩散规律和远距离迁飞的可能性。用玉米螟性诱剂回收时，两年回收到标放雄蛾一代分别为１１９和１９５头，二代分别为５３和２４９头，回收到标记蛾距释放点的最远距离均８ｋｍ，其中１－２ｋｍ范围内回收到     

玉米螟赤眼蜂适宜生境的研究与利用Ⅱ.夏玉米间作匍匐型绿豆对玉米螟赤眼蜂寄生率的影响

通过人工挂卵和自然落卵定期观察的方法，对夏玉米平作、夏玉米间作直立型和匍匐型绿豆３种生境条件对玉米螟赤眼蜂自然种群和寄生率的影响进行了研究。结果表明，间作匍匐型绿豆田中玉米螟赤眼蜂的寄生率明显高于平作田和间作直立型绿豆田。夏玉米间作匍匐型绿豆田中玉米螟赤眼蜂自然种群数量在一相当长的时间内保持较高水平，说明对赤眼蜂确有增诱作用。玉米与匍匐型绿豆的不同间作比对赤眼蜂自然种群的增诱作用明显不同，当间作比为２：１和４：１时，其增诱作用最强，随着夏玉米比例的提高，增诱作用明显减弱     

玉米螟赤眼蜂寄生卵低温保存技术初探

试验表明:冷藏玉米螟赤眼蜂的寄生卵,赤眼蜂的发育阶段、发育温度和冷藏时间,均能影响蜂的羽化率和产卵量。以在8℃、25℃变温中发育到卵后期冷藏的寄生卵,羽化率和雌蜂产卵量最高。冷藏90天,羽化率为87.5％,单雌产卵55.8粒。     

玉米螟赤眼蜂与松毛虫赤眼蜂提取液对亚洲玉米螟卵发育的影响

亚洲玉米螟Ostrinia furnacalis（Güenée）卵对玉米螟赤眼蜂Trichogramma ostriniae Pang et Chen的适合度高于对松毛虫赤眼蜂T. dendrolimi Matsamura的适合度,本文比较了两种赤眼蜂寄生不同龄期亚洲玉米螟卵的出蜂率,并利用显微注射的方法研究了两种赤眼蜂提取液对亚洲玉米螟卵发育的影响。结果表明,寄生各个龄期的玉米螟赤眼蜂出蜂率均显著大于松毛虫赤眼蜂寄生对应龄期寄主的出蜂率。玉米螟赤眼蜂整头雌蜂和高浓度雌蜂腹部提取液对卵龄为12 h亚洲玉米螟卵的孵化率都有显著影响,且玉米螟赤眼蜂的提取液能使亚洲玉米螟胚胎发育畸形;而松毛虫赤眼蜂整头雌蜂提取液和雌蜂腹部提取液对亚洲玉米螟卵的孵化率无显著影响。     

不同地理种群赤眼蜂对亚洲玉米螟的控制潜能

玉米螟赤眼蜂T.ostriniae为寄生玉米螟卵的优势种,其寄生能力无论在实验室,还是在大田均是最好的。但由于玉米螟赤眼蜂只嗜好寄生小粒卵,因此难以大面积推广应用。而利用人造卵繁殖寄生玉米螟的松毛虫赤眼蜂品系来防治亚洲玉米螟,其田间卵块与卵粒寄生率可达到79.64％和65.44％,对玉米螟的发生起了较好的抑制作用。     

利用蓖麻蚕卵繁殖玉米螟赤眼蜂试验简报

在北京、辽宁等地,玉米螟赤眼蜂是玉米螟第1～3代卵寄生蜂的优势种;人工繁殖释放后,玉米螟卵被寄生率达94.09％,玉米被害株率仅为8.2％,防治效果良好。据北京和辽宁试验,玉米螟赤眼蜂不能寄生于柞蚕卵,仅可寄生于米蛾卵中。为扩大人工繁殖寄主的范围,我们试验用蓖麻蚕卵进行繁蜂,获得了成功。现简报如下。蜂种来自北京市农科院,原寄主为米蛾卵。蜂种于1979年12月27日羽化雌蜂518头,雄蜂243头,当即接种于蓖麻蚕蛾剖腹卵中,供试卵727粒,结果卵寄生率为21.45％(156粒),子代蜂发育历期15天(12月27日～1月11日),羽化率为85.25％(143粒),平均每卵出蜂16.07头,其中雌蜂占80.85％,子代蜂寿命为7天。以后用蓖麻蚕产出卵继续繁殖,经第二、三、四代,寄生率逐渐稳定和提高。现将第四代寄生情况列入表1。     

麦蛾卵龄对玉米螟赤眼蜂寄生选择及后代质量指标的影响

比较了麦蛾卵龄对亚洲玉米螟赤眼蜂寄生以及其后代羽化率、雌蜂率、寿命和生殖力等质量指标的影响。研究结果显示,在仅供给单一卵龄寄主卵的条件下,玉米螟赤眼蜂对发育48 h以后的麦蛾卵寄生率显著降低,但在蜂卵比1:40的条件下,对卵龄48~84 h的麦蛾卵仍有不低于68.61%的寄生率,对卵龄84~96 h的麦蛾卵寄生率可达57.53%,表现出较好的寄生能力。在同时供给赤眼蜂不同卵龄寄主卵使其有选择寄生的条件下,玉米螟赤眼蜂对发育60 h以后的麦蛾卵寄生选择性显著下降,在总蜂卵比1:80的条件下,对卵龄60~72 h,卵的寄生比例达到总寄生卵数的9.13%,显著低于对卵龄低于36 h的3组卵的寄生比例,而对卵龄72~84 h、84~96 h两组卵的寄生比例则进一步降至6.46%和3.39%,显著低于卵龄60 h以内的所有处理组。对玉米螟赤眼蜂后代质量指标的测定结果显示,寄生不同卵龄麦蛾卵的赤眼蜂在试验条件下羽化率均高于95%,且处理间没有显著差异;寄生在卵龄2~12 h和12~24 h麦蛾卵内羽化的赤眼蜂雌蜂率分别为71.94%和71.40%,显著低于卵龄48 h以上各组卵内的羽化的赤眼蜂78.45%~79.79%的雌蜂率;随着寄主卵龄的增长,所羽化的赤眼蜂成蜂寿命呈下降趋势,且寄生卵龄高于60 h,寄主卵发育羽化的赤眼蜂成蜂平均存活时间降至5.3 d以下,显著低于卵龄2~12 h组6.4 d的存活时间;寄生在不同卵龄麦蛾卵上羽化的玉米螟赤眼蜂雌蜂生殖力没有显著差异。研究结果表明,玉米螟赤眼蜂对麦蛾卵的龄期有较广的选择适应性。     

江苏省第一代玉米螟幼虫的寄生率及其预测的研究

根据１９７７～１９９３年在江苏盐城的田间调查，在玉米螟幼虫期的天敌种群中，玉米螟长距茧蜂占７１．６％，玉米螟厉寄蝇占２２．４％，其它蜂占６％。一代玉米螟幼虫被寄生的幅度为１６．５～７５．８％。寄生率的高低常决定当代和下代玉米螟的发生数量。幼虫被寄生的程度与一代玉米螟卵的发生量、５月旬平均降雨量和６月旬平均气温有极显著的相关。利用回归方程式预测寄生率与田间实测的寄生率有很高的拟合性，因此可以在６月底以前利用回归方程来预测一代玉米螟的被寄生率     

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.