二点委夜蛾触角感器的超微结构研究

对二点委夜蛾成虫触角感器的形态结构进行了扫描电镜观察,结果表明:二点委夜蛾触角由柄节、梗节和鞭节组成,鞭节由72个亚节组成,触角内侧面覆盖有鳞片。雌蛾触角上存在9种感器:毛形感器、刺形感器、耳形感器、腔锥形感器、锥形感器、栓锥形感器、腔乳头状感器、鳞形感器和Bhm氏鬃毛。不同感器在触角各节上的分布与数量各不相同,且雌雄之间存在差异。鳞形感器为雌蛾特有,雄蛾触角上的毛形感器多于雌蛾,腔锥感器少于雌蛾。     

南美斑潜蝇触角感器的扫描电镜观察

利用扫描电镜对南美斑潜蝇触角形态和感器进行了观察.结果表明,南美斑潜蝇触角为具芒状,由柄节、梗节、鞭节三部分组成,鞭节上着生触角芒.触角感器有五种,分别为刺形感器、毛形感器、锥形感器、钟形感器和腔锥形感器,所有的触角感器都分布在鞭节上.雌雄成虫在触角形态、感器种类与分布上没有显著性差异.     

杂拟谷盗触角感器的扫描电镜观察

利用扫描电镜对杂拟谷盗成虫触角形态及感器进行了观察,结果表明,杂拟谷盗成虫触角为棒形,由柄节、梗节和鞭节组成,其中鞭节又分为9个亚节,不存在雌雄二型现象。雌、雄成虫触角上均存在以下6类14种感器,包括Bhm氏鬃毛、3种毛形感器、1种栓锥形感器、6种锥形感器、1种刺形感器、2种指形感器。雌雄个体之间触角感器的类型、分布、长度、基部直径没有明显差异。结合感器的形态、分布和已报道的触角电位反应数据,对杂拟谷盗触角各类感器的功能进行了推测。     

栗实象成虫触角感器超微结构观察

栗实象Curculio davidi是为害板栗Castanea mollissima的主要种实害虫,严重影响着板栗的品质和产量。为探明栗实象成虫触角感器类型、形态和分布,本文利用扫描电镜对栗实象雌雄成虫触角及触角感器进行观察。结果表明:栗实象雌雄成虫触角柄节、梗节、鞭节1~6亚节长度存在显著差异。雌、雄成虫触角上均有7类12种感器,包括4种刺形感器、2种锥形感器、1种叉形感器、2种毛形感器,1种B?hm氏鬃毛、1种腔形感器和1种端指形感器。其中雄虫刺形感器Ⅰ、毛形感器Ⅰ、叉形感器的长度显著长于雌虫,雄虫鞭节第7、8亚节的锥形感器数量显著多于雌虫。     

Q隐种烟粉虱头部感器观察及功能初步研究

为研究Q隐种烟粉虱头部感器与嗅觉的相关性,应用扫描电镜观察了Q隐种烟粉虱头部感器的分布和形态,结果表明,烟粉虱雄成虫触角长度为191.55μm,雌成虫触角长度为235.97μm明显长于雄成虫。雌、雄成虫的柄节和梗节长度均无显著性差异,雄成虫鞭节为144.90μm,雌成虫鞭节为187.34μm,雌成虫明显长于雄成虫,但两者在感器形态、大小、位置和数量上无显著性差异。雌、雄成虫的头部均有微毛感器、刺形感器、腔锥感器、锥形感器和钟形感器等5种感器。其中,微毛感器和刺形感器在头部分布广泛,数量众多。腔锥感器、锥形感器和钟形感器仅存在于触角上,且主要位于触角鞭节的背面和腹面,锥形感器的长度最长,雌、雄成虫的锥形感器长度分别为11.37和11.67μm。在分别对触角、梗节和鞭节进行切除后,烟粉虱成虫对其嗜食寄主黄瓜失去趋向性,表明触角鞭节是Q隐种烟粉虱的重要嗅觉器官。触角鞭节上的感器在雌、雄Q隐种烟粉虱成虫对黄瓜幼苗气味选择的过程中起重要作用,而位于触角柄节和梗节上的感器对黄瓜气味没有识别作用。     

轮纹异痂蝗触角感器的扫描电镜观察

利用扫描电镜观察了轮纹异痂蝗[Bryodemella tuberculatum dilutum(Stoll)]成虫触角感器的类型和分布。结果表明:轮纹异痂蝗触角为丝状,由柄节、梗节和鞭节组成,雄性个体鞭节包括24个亚节,雌性个体鞭节包括23个亚节。雌雄个体均具有12种感受器,即毛形感受器、刺形感受器(Ⅰ型和Ⅱ型)、锥形感受器(Ⅰ型、Ⅱ型、Ⅲ型、Ⅳ型和Ⅴ型)、腔锥形感受器、腔形感受器及Bhm氏鬃毛。根据各类感器的形态、分布和显微结构探讨了其可能承担的功能。     

钩臀蚁蛉头部附器感器的超微结构观察

利用扫描电镜技术对钩臀蚁蛉Myrmeleon bore(Tjeder)雌、雄成虫头部附器感器类型、形态、数量与分布进行观察。结果表明:钩臀蚁蛉成虫触角为棒状,由柄节、梗节和鞭节组成,其中鞭节约由38个亚节组成。成虫触角和口器上共有7类14种感器,分别是B#x00F6;hm氏鬃毛、毛形感器(5种)、锥形感器(4种)、腔乳头形感器、腔形感器、刺形感器及钟形感器。不同感器在触角和口器下颚须、下唇须上的分布与数量各不相同,雌、雄成虫之间无差异。结合感器的形态、分布和已报道感器功能的相关研究等,对钩臀蚁蛉的触角各类型感器的功能进行了分析与推测。     

暗黑鳃金龟触角超微结构

利用扫描电镜对暗黑鳃金龟(Holotrichia parallela)雌、雄成虫的触角形态和感器进行了观察。结果表明:暗黑鳃金龟触角分为4部分,即柄节、梗节、鞭节棒状部和鳃状部,其中鞭节棒状部由5节组成,鳃状部由鞭节末端3节扩展构成。暗黑鳃金龟触角感器共7种,分别为板形感器、腔锥感器、腔形感器、刺形感器、毛形感器、锥形感器和Bhm氏鬃毛。雌、雄个体之间触角感器的类型、分布均没有明显差异。不同感器在触角各节上的数量与分布各不同。     

豆卜馍夜蛾触角感器的超微结构与分布

为了解豆卜馍夜蛾Bomolocha tristalis Lederer成虫触角感器的类型、超微结构、数量和分布,探索其化学感受机制。利用扫描电镜技术对豆卜馍夜蛾雌、雄蛾的触角感器进行观察。结果表明:在豆卜馍夜蛾触角上共观察到8种类型感器:B?hm氏鬃毛(两种亚型,BBⅠ型和BBⅡ型)、毛形感器、锥形感器、刺形感器、腔锥形感器、耳形感器、鳞形感器和栓锥形感器。其中毛形感器数量最多,其次是腔锥形,除刺形和栓锥形感器外,其他感器数量在触角鞭节从基部到端部呈现由少到多,再减少的趋势。毛形、锥形和耳形感器表皮具多孔属于嗅觉感器。雄蛾触角与雌蛾相比,鞭亚节多2～4节;毛形、刺形和鳞形感器明显长于雌蛾,耳形感器明显短于雌蛾;毛形和腔锥形感器数量均明显多于雌蛾。豆卜馍夜蛾触角感器种类丰富,数量较多,雌、雄蛾间存在性二型现象,B?hm氏鬃毛、刺形和栓锥形感器在结构和分布上存在有利其功能的特化现象。     

马铃薯甲虫成虫触角及感器的扫描电镜观察

为了系统的了解与掌握马铃薯甲虫成虫触角感器的类型及分布,本研究利用扫描电镜对马铃薯甲虫雌、雄成虫的触角形态特征及超微结构进行了观察.研究结果表明:触角由柄节、梗节及鞭节组成;马铃薯甲虫雌雄成虫触角感器共分为4类13种,即3种毛形感器(ST1、ST2、ST3)、7种锥形感器(SB1、SB2、SB3、SB4、SB5、SB6...     

Application of reverse-phase h.p.l.c. for the determination of partition coefficients

Reverse-phase high performance liquid chromatography (h.p.l.c.), using a C₁₈ analytical column, has been applied to the determination of partition coefficients for a range of agrochemicals and industrial chemicals. Using a correlation plot of the logarithm of the capacity factor (k) with the logarithm of the n-octanol/water partition coefficient (P_ow), partition coefficients were predicted with a 95% tolerance interval of ± log 0.80 of the literature ‘shake flask’ value for compounds of random structure over the log P_ow range 0–6. Individual regression lines were fitted for compounds of comparable size and functional grouping, which reduced any bias and thereby enabled more accurate predictions to be made. The reverse-phase h.p.l.c. method has a number of advantages over the traditional ‘shake-flask’ method. Quantitative methods are not required or do not have to be developed and only the determination of the retention time is necessary. Quick and precise determinations of retention times are facilitated by h.p.l.c. and further improvement can be obtained by automation of solvent mixing, solute injection and data processing. H.p.l.c. was used to generate partition coefficient data for highly hydrophobic materials and, because of its resolving power, data for mixtures and solvent fractions. Dual detection, using u.v. and r.i. in series, was necessary for some compounds, particularly unknown mixtures and impure compounds. Calculations of log P_ow based on the fragment-addition method using the structural data file, MACCS, was of considerable value in confirming experimentally derived values. In certain cases, calculated log P_ow values were considered more trustworthy than experimental values.     

PCR-based differentiation of Fusarium oxysporum ff. sp. lycopersici and radicis-lycopersici and races of F. oxysporum f. sp. lycopersici

The pathogenic type (form and race) of Fusarium oxysporum, which generates wilt symptoms on tomato, was rapidly identified with a polymerase chain reaction (PCR)-based technique. We compared the partial nucleotide sequences of endo polygalacturonase (pg1) and exo polygalacturonase (pgx4) genes from isolates of F. oxysporum ff. sp. lycopersici (FOL) and radicis-lycopersici (FORL) from Japan and designed specific primer sets (uni, sp13, sp23, and sprl) based on the nucleotide differences that appeared among the pathogenic types. PCR with the uni primer set amplified a 670∼672-bp fragment from all isolates of FOL and FORL. With the sp13 primer set, an amplicon of 445 bp was obtained only from isolates of FOL race 1 and 3. With the sp23 primer set, a 518-bp fragment was obtained from isolates of FOL race 2 and 3. The sprl primer set yielded a 947-bp fragment from isolates of FORL, but not from FOL. A combination of amplifications with these primer sets effectively differentiated the pathogenic types of F. oxysporum in tomato.     

Dispersal of Formulations of Fusarium oxysporum f. sp. erythroxyli and F. oxysporum f. sp. melonis by Ants

ABSTRACT A natural epidemic of Fusarium wilt on coca (Erythroxylum coca) in Peru prompted the suggestion of possibly using the pathogen Fusarium oxysporum f. sp. erythroxyli as a mycoherbicide against this narcotic plant. During field trials conducted in Kauai, HI, to test the pathogenicity of the coca wilt pathogen, ants were observed removing formulations from test plots. While removal of formulations by ants was considered detrimental with respect to conducting field tests, ant removal was considered potentially beneficial in disseminating the mycoherbicide. Thus, research was initiated to assess the ability of formulation additives to alter the preference of ants for the formulated mycoherbicide. In Hawaii, preference of indigenous ants for removing formulations was tested using three different food bases (rice, rice plus canola oil, and wheat flour [gluten]). Similar tests were conducted at Beltsville, MD, using F. oxysporum f. sp. melonis, in which the formulation based on wheat flour was replaced by a formulation based on canola meal. Formulations based on wheat were preferred by ants in both locations; up to 90% of the wheat plus rice flour granules (C-6) and the wheat gluten plus kaolin granules (pesta) were removed within 24 h, while only 20% of those containing rice without oils were taken. However, when either canola, sunflower (Maryland only), or olive oil was added to the rice formulation, up to 90% of the granules were taken. The formulation based on canola meal was less attractive to ants, as only 65% of the granules were removed within a period of 24 h. Ants showed no preference with respect to presence or absence of fungal biomass. To alter the attractiveness of the C-6 formulation to ants, C-6 was amended with three natural products. Canna and tansy leaves were added to C-6 at a ratio of 1:5 (wt/wt), while chili powder was added at 1:25 or 1:2.5 (wt/wt). Canna, tansy, and the higher rate of chili powder significantly reduced the number of C-6 granules removed by ants. Canna and tansy leaves affected neither germination nor sporulation of the mycoherbicide, while the high concentration of chili powder reduced viability of propagules in the formulation. More F. oxysporum f. sp. erythroxyli-type colonies were recovered from inside ant nests (9 cm depth) than from nest surfaces, indicating that ants may distribute the mycoherbicide in the soil profile. Ants passively carried propagules of F. oxysporum f. sp. erythroxyli outside their bodies, as well as either very closely adhering to the outside or within their bodies.     

醉蝶白粉病的发生规律与防治

研究明确醉蝶白粉病菌以闭囊壳、分生孢子和菌丝在病残体上或土壤中越冬。醉蝶开花至盛花期为发生高峰期 ,高温干燥的气候条件发病严重。发生程度与土壤肥力、田间种植密度等关系密切。加强管理 ,清洁田园和30%特富灵、6%乐必耕、75%百菌清、25%粉锈宁可湿性粉剂等在定植后、开花前后喷药 ,每隔10d1次 ,连续5～6次 ,可基本控制该病发生。     

美国出境旅游市场特征及旅华美国市场拓展对策研究

美国是世界出游大国,同时也是我国第一大远程客源国和第四大入境旅游客源国,在我国入境旅游市场中占据着举足轻重的地位。文中运用2001-2010年美国出境旅游市场统计数据,采用季节变动指数、地理集中指数和首位度、位序-规模分布等理论,通过对美国出境旅游市场规模变化、季节分布、全球流向分布及在中国和亚洲其他国家之间分配特征的研究,提出拓展旅华美国市场的对策。研究发现美国出境旅游市场具有以下特征:1)出境旅游市场规模大且持续增长,但是受国内和国际危机事件影响显著;出境旅游旺季在3月、6月、7月和12月,最主要的出境旅游目的地是墨西哥、加拿大和欧洲,亚洲虽非美国人的主要旅游目的地,但其占美国出境市场的份额逐年上升;2)美国人在亚洲旅游的主要目的地包括日本、中国大陆、印度、中国香港、韩国、中国台湾等6个国家和地区;3)中国大陆对美国出境市场的旅游吸引力持续上升,日本对美国市场的垄断地位开始动摇,但仍是中国大陆最大的竞争对手。最后,根据研究结论提出旅华美国市场的拓展对策。