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Concentrations of DDT, TDE, DDE, and sigma DDT were determined in homogenized whole fish samples of 129 northern pike (Esox lucius). These fish were netted between June 1974 and June 1975 in the first 10 km of the Richelieu River flowing in Canadian territory. Two years after the banning of DDT, sigma DDT levels ranged from 0.2 ppm fresh body weight in two-year-old specimens to 1.5 ppm in a six-year-old pike. Residues increased greatly with age, and significant seasonal variations in the sigma DDT levels were found in five- and six-year-old pike. 相似文献
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Brant SV 《Folia parasitologica》2007,54(2):99-104
Twelve tundra swans, Cygnus columbianus (Ord), from Nevada and one from New Mexico were collected and examined for schistosomes. Mature worms, determined as Allobilharzia visceralis, were found in 92% of the swans, in the inferior mesenteric vein of the large intestine and its branches. In 12 cases, there was endophlebitis of the inferior mesenteric vein. The morphology of the worms is consistent with the recently described genus Allobilharzia. Placement in this genus was confirmed also by phylogenetic analysis of nuclear 28S, 18S and, internal transcribed spacer (ITS) ribosomal DNA (rDNA), and mitochondrial cytochrome oxidase I (CO1) sequences. Data further suggest the worms are con-specific with the European A. visceralis, the only described species of the genus and which was found to be the sister taxon to the most diverse avian schistosome genus, Trichobilharzia. This is the first report of a schistosome infection from native swans in North America. 相似文献
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Wilhelm Dercks Stefanie Hackel Hannes Witte Malte Michaelsen Mandy Neuber Ute Gärber Hubertus Kleeberg 《Gesunde Pflanzen》2014,66(1):1-16
Plant extracts (botanicals) are of special significance for plant protection, especially in organic farming. This is due to their origin, specific modes of action, toxicological and ecotoxicological properties as well as to ever changing legal, patent, economic and social/political issues. This paper surveys this complex background and presents data on two selected botanicals which pertain to the use of extract fractions from Glycyrrhiza glabra (sweet wood) for control of Bremia lactucae (downy mildew) in lettuce and azadirachtin for control of leafhoppers in Melissa officinalis L. Both compounds exhibited good effects in the greenhouse which were less pronounced or absent in the field. The effects of sweet wood were strongest when applied twice preventively at 5?% concentration. In the greenhouse, this resulted in a lower number of infected plants and smaller leaf areas attacked by the downy mildew pathogen at high disease pressure. Azadirachtin (plant protection chemical NeemAzal®-T/S in combination with the additive Trifolio S-forte; 1.5 l/ha + 3 l/ha in 600 l water per hektar, 3 applications, interval 7 days) was better in controlling leaf hoppers than natural pyrethrins in combination with rapeseed oil (Spruzit Schädlingsfrei; 6 l/ha in 1,000 l water per hektar, 1 application) in the greenhouse and exhibited very high insecticidal efficacy almost equivalent to that of thiacloprid (Calypso 480 SC; 0.12 l/ha in 400 l water per hektar, 1 application) at moderate disease pressure. Thiacloprid, however, is not applicable in organic farming. In order to introduce these promising results in practical plant protection further fundamental studies are needed. These can only be realized by a joint effort of private companies, research and plant protection institutions, as well as public funding bodies. This article is not meant as a presentation of “perfect” results, it is rather an example of the problems and pitfalls that need to be overcome during development of a botanical and its applications. They are the reason why the market for botanicals will remain small. 相似文献
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正十四点负泥虫属鞘翅目叶甲科Chrysomelidae。寄主植物有石刁柏(芦笋)、文竹等百合科天门冬属植物,可成为芦笋的害虫。幼虫(封面图片a)不负泥。成虫体长5.5~7.5mm;棕黄色或橘红色(封面图片b),具黑斑;头前端、复眼及四周、触角均 相似文献
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Calliteara pudibunda is a univoltine, polyphagous and native species producing periodic outbreaks which have been recorded only in Europe so far. Its larvae feed on the foliage of beech, oak and several other deciduous and coniferous trees. It is very widespread in Eurasia. In Europe, it is found between the 34th and 60th parallels. In Türkiye, it occurs mainly in coastal regions. Its outbreak range had been thought to be confined between the 48th and 57th parallels in Europe until the last two decades when outbreaks occurred in Italy and Türkiye. Therefore, the southern limit of its outbreak range can be updated as the 36th parallel. The outbreaks recur every 20–30 years, typically continue for 1–2 years, and end suddenly. Favourable meteorological conditions and a temporary rarity of parasitoids seem to be the main causes of the outbreaks. The damage on hosts is not evident until the third larval instar. The affected hosts may grow new shoots the next spring, as the larvae usually do not attack the terminal shoots. Increment loss is possible, but it may not be economically significant per se. However, tree mortality can occur with the combined effects of other stress factors. The impact of parasitoids and predators during the outbreaks is low. There are also fungal species identified from larvae and pupae, some of which might have significant potential in pest management. Additionally, Bacillus thuringiensis var. kurstaki (Btk), polyhedrosis viruses and light traps can potentially be used, although management practices are not recommended in C. pudibunda outbreaks. 相似文献
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在中国的赤眼蜂属(庞雄飞和陈泰鲁,1974,1978)中记述了分布于我国的12种赤眼蜂,其中个别种的学名仍有争议。此外,在过去的一些资料中曾记述过其他种名。不少读者来信询及这些问题,我们在这里提出简单的讨论。 1.螟黄赤眼蜂Trichogramma chilonis Ishii Flanders et Guednau(1960)把该种列入稻螟赤眼蜂T.japonicum Ashmead的异名,Doutt et Viggiani(1968)也没有列入该种。我们认为,把该种列为稻螟赤眼蜂T.japonicum Ashmead的异名不一定恰当。Ishii(1941)在首次描述该种时,曾在附图中把这两种的雄性外生殖器特征作了比较,看来,螟黄赤眼蜂T.chilonis Ishii的雄性外生殖器比较特殊,应为独立的种。在Ishii的原描述中,记录了该种首次采于菲律 相似文献
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SONG Yujia LIU Xijun XIAO Wenjiao ZHANG Zhiguo LIU Pengde XIAO Yao LI Rui WANG Baohua LIU Lei HU Rongguo 《干旱区科学》2022,14(1):82-101
The Central Tianshan Block is one of numerous microcontinental blocks within the Central Asian Orogenic Belt(CAOB)that overlies Precambrian basement rocks.Constraining the evolution of these ancient basement rocks is central to understanding the accretionary and collisional tectonics of the CAOB,and their place within the Rodinia supercontinent.However,to date,the timing and tectonic settings in which the basement rocks in the Central Tianshan Block formed are poorly constrained,with only sparse geochemical and geochronological data from granitic rocks within the northern segment of the block.Here,we present a systematic study combining U-Pb geochronology,whole-rock geochemistry,and the Sr-Nd isotopic compositions of newly-identified granitic gneisses from the Bingdaban area of Central Tianshan Block.The analyzed samples yield a weighted mean Neoproterozoic 206Pb/238U ages of 975-911 Ma.These weakly-peraluminous granitic rocks show a common geochemical I-type granite affinity.The granitic gneisses are calc-alkaline and enriched in large ion lithophile elements(LILEs)and light rare earth elements(LREEs),but they are depleted in high field strength elements(HFSEs);these characteristics are similar to those of typical subduction-related magmatism.All samples show initial(87Sr/86Sr)(t)ratios between 0.705136 and 0.706745.Values forεNd(t)in the granitic gneisses are in the range from-5.7 to-1.2,which correspond to Nd model ages of 2.0-1.7 Ga,indicating a role for Mesoproterozoic to Paleoproterozoic rocks in the generation of the granitic protoliths.The documented geochemical features indicate that the protoliths for the gneisses have a similar petrogenesis and magmatic source,which may reflect partial melting of thickened crust with the addition of small amounts of mantle-derived material.The Central Tianshan Block probably constitute part of an exterior orogen that developed along the margin of the Rodinian supercontinent during the Early Neoproterozoic and underwent a transition from subduction to syn-collision compression at 975-911 Ma. 相似文献
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Pterygodermaties (Mesopectines) nycticebi (M?nnig, 1920) (Nematoda: Spirurida: Rictulariidae) is redescribed based on immature and mature adults collected from the stomach and small intestine at autopsy of a slow loris, Nycticebus coucang (Boddaert, 1785) (Mammalia: Primates), in a zoological garden in Japan. It is first demonstrated that male possesses a minute telamon and a left lateral pore in the preanal part of body. The cause of death of the slow loris is strongly surmised to be related to the nematode infection, which was apparently acquired under captivity in the zoological garden. 相似文献
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Abstract A field trial was conducted to study the magnitude of quinalphos residues in and/or cauliflower (Brassica oleracea Var Botrytis. The cauliflower crop was sprayed once with quinalphos 25 e.c. at 0.25 and 0.5 kg a.i./ha 104 days after transplanting. The samples of cauliflower drawn at different time intervals were analysed colorimetrically. The initial deposits of quinalphos on cauliflower were found to be 5.79 and 9.52 ppm, an the half life values 1.61 and 2.12 days, respectively, at 0.25 and 0.5 kg a.i./ha. The waiting periods determined were 11 days at the higher and 7 days at the lower dose of quinalphos. 相似文献
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二、薄层色谱测定法用邻-联甲苯胺加碘化钾、对-硝基苯重氮氟硼酸盐、真菌生物测定和酶、硝酸银加紫外光(UV)照射和对一二甲胺基苯甲醛等测定方式,均已选作未知来源样品提取液中农药残留的TLC 筛分方法。洗提时使用单一溶剂,R_f 值的变异系数作为 R_f 和洗提剂的函数进行研究。使用指示化合物以控制适当的检测条件。检验了188种农药化合物的可检测性,确定了其最低检出量。 相似文献
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da Cruz Wilton Pires Souza Magno Chagas Lacerda José Dantas Araújo Souza Áurea Izabel Aguiar Fonseca e Silva Priscilla Andrade dos Santos Elenilza Cruz 《植物病害和植物保护杂志》2023,130(1):199-204
Journal of Plant Diseases and Protection - The red palm mite Raoiella indica Hirst attacks coconut, banana and açai trees. In 2007, the mite was recorded for the first time in South America.... 相似文献
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M. Tomczak H. Wiśniewska Ł Stcępień M. Kostecki J. Chełkowski P. Goliński 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(7):625-630
Fusarium head blight (scab) epidemics of wheat occurred in uawy (Northern Poland) during 1998 and in Wielkopolska (West) and in Southern regions of Poland in 1999. Four species were identified in wheat heads with scab symptoms: Fusarium culmorum, Fusarium graminearum, Fusarium avenaceum and Microdochium nivale. A significant increase in the frequency of F. graminearum (between 23% and 38%), was observed, compared to about 10% during the previous decade. The mycotoxins deoxynivalenol (DON), nivalenol (NIV) and moniliformin (MON) in amounts up to 24.3, 14.2 and 1.72mgkg–1respectively, were identified in kernels samples. 相似文献
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Aleš Lebeda Yigal Cohen 《European journal of plant pathology / European Foundation for Plant Pathology》2011,129(2):157-192
Cucurbit downy mildew, caused by the oomycete Pseudoperonospora cubensis, is a devastating, worldwide-distributed disease of cucurbit crops in the open field and under cover. This review provides
recent data on the taxonomy, biology, ecology, host range, geographic distribution and epidemiology of P. cubensis. Special attention is given to host-pathogen interactions between P. cubensis and its economically-important cucurbit hosts (Cucumis sativus, C. melo, Cucurbita pepo, C. maxima, and Citrullus lanatus); pathogenic variability in P. cubensis at the species, genus, and population levels; and, differentiation of pathotypes and races. Genetics and variability of host
resistance and cellular and molecular aspects of such resistance are considered. A focus is given to methods of crop protection,
including prevention and agrotechnical aspects, breeding for resistance—classical and transgenic approaches, chemical control
and fungicide resistance. Novel technologies in biological and integrated control are also discussed. This review also summarizes
the most important topics for future research and international collaboration. 相似文献
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Abstract: The adult male of dracunculoid nematode Ichthyofilaria argentinensis Incorvaia, 1999 (Guyanemidae) is described for the first time based on specimens found in the swimbladder of its type host, Merluccius hubbsi Marini (Merlucciidae), caught off the coast of Buenos Aires, Argentina (western Atlantic Ocean). In addition, the males of Ichthyofilaria bergensis (Wülker, 1930) K?ie, 1993 are redescribed from specimens collected from the body cavity and visceral surface of Molva macrophthalma (Rafinesque) (Lotidae) caught in the western Mediterranean Sea, off the coast of Sardinia. Light and scanning electron microscopy examinations revealed some new morphological features for the genus, such as a pair of deirids located near the end of muscular oesophagus, the body wall conspicuously twisted immediately anterior to the cloaca, the presence of a copulatory plate, one pair of adcloacal papillae and a pair of phasmids situated on the posterior half of the tail. On the basis of this material, the generic diagnosis of Ichthyofilaria is modified to include some of these newly observed features, as well as to indicate the absence of spicules. The diagnosis of Guyanemidae is extended to include that a copulatory plate and/or two spicules may be present as characteristics for this family. 相似文献
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