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1.
The origin of olfactory stimuli involved in the host microhabitat location inCotesia flavipes, a parasitoid of stem-borer larvae, was investigated in a Y-tube olfactometer. The response of femaleC. flavipes towards different components of the plant-host complex, consisting of a maize plant infested with two or more larvae of the stem borerChilo partellus, was tested in dualchoice tests. The concealed lifestyle of the stem-borer larvae did not limit the emission of volatiles attractive to a parasitoid. A major source of the attractive volatiles from the plant-host complex was the stem-borer-injured stem, including the frass produced by the feeding larvae. Moreover, the production of volatiles attractive to a parasitoid was not restricted to the infested stem part but occurs systemically throughout the plant. The uninfested leaves of a stem-borer-infested plant were found to emit volatiles that attract femaleC. flavipes. We further demonstrate that an exogenous elicitor of this systemic plant response is situated in the regurgitate of a stem-borer larva. When a minor amount of regurgitate is inoculated into the stem of an uninfested plant, the leaves of the treated plant emit volatiles that attract femaleC. flavipes. 相似文献
2.
The pheromone of the eastern tent caterpillar,Malacosoma americanum (F.) (lepidoptera,Lasiocampidae)
Jan Kochansky Ada Hill John W. Neal Jr. Jo-Ann Bentz Wendell Roelofs 《Journal of chemical ecology》1996,22(12):2251-2261
The pheromone system of the eastern tent caterpillar,M. americanum, has been identified as a mixture of (E,Z)-5,7-dodecadienal and the corresponding alcohol. Field data on the attractiveness of the aldehyde alone were not consistent, but mixtures of aldehyde and alcohol in varying proportions were attractive to males. Addition of small amounts ofE,Z acetate toE,Z aldehyde had no effect on male response, but larger amounts reduced trap catch. Traps baited withZ,E, E,E, orZ,Z aldehydes were not more attractive than blank traps. Pherocon IC traps fortified with extra adhesive and baited with lures consisting of 500 µg (E,Z)-5,7-dodecadienal with either 250 or 100 µg of the corresponding alcohol trapped as many as 100 males/trap/night with means of 15–20. Lures prepared from purified (94%E,Z) aldehyde and alcohol were more attractive than those prepared from unpurified (58%E,Z) materials.DeceasedMention of a company name or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture. 相似文献
3.
The antioxidant -tocopherol (vitamin E), applied in a basal trunk band to the green ash tree,Fraxinus pennsylvanica var.subintergerrinia, elicited an alteration of foliar feeding byMalacosoma disstria larvae (Lepidoptera: Lasiocampidae). The bioassayed effects were dependent on the dosage of elicitor, the time after elicitation, and the position in the tree. Leaves for chemical analysis were collected from trees receiving two dosages and at two intervals after elicitation. Compounds in the ethyl acetate extractables from the ash tree leaves were separated by TLC and HPLC. TLC separations showed differences in the nonhydrolyzed extractables attributable to elicitor dosage and time after elicitation. TLC-resolved differences were also evident among acid-hydrolyzed samples. HPLC-resolved profiles revealed eight peaks in the nonhydrolyzed extractables that were quantitatively negatively correlated with larval feeding preference between elicited versus control foliage on at least one of the two sampling dates. Results from this study and other investigations reported in the literature indicate that the antioxidant-tocopherol (vitamin E) can function as an environmental-stress elicitor of alterable defensive chemistry in green ash and other plants. 相似文献
4.
德国DEMAG公司近年生产的450T级的cc2500履带吊,配置了PDC模块,具备了强大的故障诊断功能,能够监控吊机的许多工作参数.目前国内大型工程中也在使用cc2500吊机,联系实际维修情况,总结cc2500故障诊断方法,为大型履带吊故障诊断提供参考. 相似文献
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Jian-Ping Yuan Jiang-Hai WangXin Liu Hui-Cong KuangShu-Yan Zhao 《Food chemistry》2007,105(4):1755-1759
The caterpillar-shaped Chinese medicinal mushroom Cordyceps sinensis consists of the fruiting body (CsA) and the host caterpillar (CsB). Ergosterol is a principal sterol in fungi and can indicate the level of mycelia of C. sinensis. Ergosterol is present in two forms, as free ergosterol and esterified ergosterol, which have different physiological functions. The relative abundances of free to esterified ergosterol are different among the various species. In the present study, a gradient reversed-phase high-performance liquid chromatography (HPLC) method was developed for the simultaneous determination of free and esterified ergosterol in CsA and CsB of C. sinensis. The results showed that CsA and CsB had similar ergosterol compositions, but the level of ergosteryl esters in CsB was much higher than that in CsA, indicating that CsA and CsB might be in different growth phase or have different physiological functions for the growth and multiplication of C. sinensis. 相似文献
8.
以太原市西华苑小区3号住宅楼工程为例,从导轨式爬架的爬升原理、性能指标、布置方案、安装、升降操作及安全保证措施等方面进行了研究论述,从而为导轨式爬架的推广应用奠定了基础。 相似文献
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Piubelli GC Hoffmann-Campo CB Moscardi F Miyakubo SH de Oliveira MC 《Journal of chemical ecology》2005,31(7):1509-1525
The identification and quantification of flavonoids (rutin and genistin) present in extracts of soybean genotypes, and their effects on the biology and physiology of Anticarsia gemmatalis Hübner (Lep.: Noctuidae) were studied. Analysis of covariance and bicoordinate utilization plots were used to remove the effect of feeding time from pupal weight and consumption as well as to separate pre- and postingestive effects of treatment on A. gemmatalis growth. Genotypes PI 274454, PI 227687, and “IAC-100” extracts in general, caused higher mortality, negatively influenced initial larval and pupal weight, and elongated larval cycle. Larvae fed on the “IAC-100” extract diet ingested larger amounts of food per unit of time, but were less efficient in its conversion to biomass. Leaf extracts of PI 227687 had the largest concentration of rutin (quercitin 3-O-rhamnosylglucoside), followed by PI 274454, and “IAC-100”; PI 74454 also had the highest genistin (genistein 7-O-glucoside) content. The susceptible cultivar “BR-16” showed only a kaempferol-based flavonoid in its chemical profile, indicating that after successive crosses, secondary compounds responsible for plant defenses were eliminated. Genotypes PI 274454, PI 227687, and “IAC-100” showed accentuated resistance characteristics and were considered inadequate sources for the development of A. gemmatalis. Considering rutin and genistin concentration in these genotypes, it is suggested that flavonoids are important factors conferring resistance to A. gemmatalis. 相似文献