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101.
Z. Mendel 《Phytoparasitica》1988,16(2):101-108
The occurrence of nests of the pine processionary caterpillar (PPC),Thaumetopoea wilkinsoni Tarns (Lepidoptera: Thaumetopoeidae), was recorded in two 9-year-old plots planted withPinus halepensis, P. brutia andP. eldarica in a randomized block design. Nest density was highest inP. eldarica and lowest inP. halepensis. The mean number of nests per tree and their frequency distribution indicate that the preference of the PPC is in the order P.eldarica >P brutia >P. halepensis;it is believed to be related to shape of the tree. Planting ofP. eldarica in camping sites is not recommended, due to its high susceptibility to colonization by the PPC. 相似文献
102.
对FC株猪源性肠毒素型大肠杆菌致病因子的研究 总被引:1,自引:0,他引:1
FC菌株是一株从腹泻仔猪粪便中分离的肠毒素型大肠杆菌(Enterotoxigenic E.coli,ETEC)。在MRHA反应中,本菌能凝集人O型、豚鼠、马、绵羊、牛、鸡和兔的红细胞,对人O型和豚鼠红细胞有很高的血凝性,血抗K88和K99血清不能抑制其对豚鼠和绵羊红细胞的血凝。在体外小肠上皮细胞吸附试验中,本菌对仔猪小肠上皮细胞具有强烈的吸附作用;透射电镜和扫描电镜观察证实了FC株菌除表面具有一种纤毛样结构外,还能定居在仔猪小肠段。血清学试验结果表明,本菌的O抗原属于O101。K88和987P两种抗血清均不能凝集本菌,而K99和F41抗血清均可凝集。对纯化的FC株菌粘着素抗原作等电聚焦和聚丙烯酰胺凝胶电泳分析,结果表明,该菌的粘着素是由等电点分别为4.61和9.78,分子量分别为29500和17500的两种蛋白质抗原所组成。此外,用乳鼠胃内投服试验和兔肠结扎试验证明,该菌只产生热稳定肠毒素。总之,本菌是一株能产生ST的K99,F41的肠毒素型大肠杆菌。 相似文献
103.
104.
The effect of trifluralin on the growth and development of cotton plants in low-organic-matter soils from the northern Negev of Israel was studied. Trifluralin exhibited linear sorp tion isotherms on these soils, Trifluralin and dinitramine losses from soils under varying moisture regimes and application practices were determined in open systems. The data were fitted to both first-order and biexponential kinetic equations. In about 50% of cases the biexponential kinetic model provided a better fit to the data, but no relationship could be found between the model parameters and environmental or soil properties. Losses were generally greater at field capacity than at 50% field capacity, and at 27°C than at 15°C, and in soils with a lower organic matter content. The trifluralin application rate was negatively correlated with vegetative growth parameters of cotton, but the correlation became weaker with increasing soil organic carbon content. Trifluralin delayed boll production in coarse textured soils, the longest delay occurring at higher application rates. It is concluded that in light soils that contain very little organic matter, trifluralin rates must be maintained at the minimum level required for adequate weed control to prevent damage to crops. 相似文献
105.
106.
The paper presents the results of faunistic, ecological and viral investigations concerning phlebotomine sandflies in an endemic focus of visceral leishmaniasis in Yugoslavia. These investigations were carried out in the period from 1969 to 1981. 相似文献
107.
Samples of blood sera collected from 608 sheep in large farms of the districts of Trebisov, Michalovce, Vranov nad Toplou and Humenné were investigated in hemagglutination-inhibition test for the presence of mosquito-borne viruses Sindbis, West Nile, Tahyna and Calovo. Antibodies to arboviruses Tahyna (11.5%) and Calovo (10.9%) were detected most frequently, while a lower sero-positivity was recorded to the Sindbis (2.3%) and West-Nile (1.0%) viruses. Certain differences were found in the infection rates in the respective districts: the highest frequency of antibodies to Tahyna and Calovo viruses was recorded in sheep of the district of Trebisov and the lowest one in animals of the district of Humenné. 相似文献
108.
Rhabdovirus-like particles containing nucleoprotein in a helix with eight turns was demonstrated by transmission electron microscopy in subtegumental cells and syncytial layer of tegument in Brachylaimus fuscatus sporocyst. This is the first case of virus infection in trematodes. The possibility of transfer of the virus to intra-molluscan parasitic generations of the trematode is discussed with respect to the peculiarities of the life cycles of the family Brachylaimidae. 相似文献
109.
Cotton was grown in loess soil, in rows 1 m apart, and drip-lines were placed in the center of every second space between rows at a distance of 50 cm from the plants. Aldicarb was applied as granules (containing 15% a.i.) to the field on two dates (mid-June and mid-July) and incorporated into the soil(a) 25 cm from the plants,i.e., equidistant from the plants and the drip-lines, on both sides of the drip-lines; and(b) 50 cm from the plants,i.e., in the center of the spaçe between the rows, near the drip-line. Measurements of mortality ofBemisia tabaci larvae, and of the accumulation of aldicarb from the late (mid-July) treatment showed that best control of the pest and the highest aldicarb residues were obtained with the late treatment. The pest control effectiveness was found to depend on both date and location of aldicarb application. Early treatment (mid-June) was more effective if applied close (25 cm distance) to the plant stems, whereas late treatment (mid-July) was more effective if applied at a distance of 50 cm from the plant stems. 相似文献
110.
All North American plum cultivars investigated in Poland for their reaction to plum pox potyvirus appeared to be susceptible, showing severe symptoms on the leaves. Fruits of cvs Valor and Empress were also heavily damaged. Of the Yugoslav cultivars evaluated, Cacanska Najbolja was most tolerant whereas Cacanska Rodna appeared to be most sensitive to PPV. 相似文献