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Catherine Taverny Isabelle Ortusi Charles Roqueplo Mario Lepage Patrick Lambert 《Ecology of Freshwater Fish》2012,21(1):87-99
Abstract – Habitat requirements of lamprey ammocoetes (Petromyzon marinus and Lampetra genus) were investigated, for the first time, from shallow to deep waters, at different spatial scales across the Gironde‐Dordogne continuum, thanks to a water suction dredge. Fish‐habitat relationships were assessed through two complementary statistical analyses: habitat‐use curves and habitat suitability models using the Boosted Regression Trees (BRT) technique. Analyses were performed on a small‐size data set that was characterised by the low prevalence of lamprey. The sea lamprey larvae occurred in deeper areas than their Lampetra genus counterparts. ‘Pools’ of 2 m’ depth and more were optimal habitats for the former species. Among the environmental variables retained to model lamprey occurrences, the mesohabitat (a categorical variable) was demonstrated to be highly influential, in terms of fine grain‐size substratum and vegetation cover. These preliminary results suggest that monitoring using the water suction dredge method may contribute to sea lamprey conservation. 相似文献
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Irene Vänninen Heikki Hokkanen Johanna Tyni‐Juslin 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):167-183
Finnish isolates of Beauveria bassiana (8 isolates), Metarhizium anisopliae (7), Tolypocladium sp. (2), Paecilomyces farinosus (2), P. fumosoroseus (1), Steinernema feltiae (3) and Bacillus thuringiensis ('Muscabac') were tested for efficacy against mixed populations of Delia radicum and D. floralis under field conditions in 1986–90. All pathogens were applied preventatively, the fungi as aqueous conidial or mycelial suspensions, dry conidia or dry mycelial powder. In only two of the nine experiments did B. bassiana or M. anisopliae give some control. In 1986, B. bassiana SF85–2 and Tolypocladium sp. SF85–4 (both at rate 1.2 x 109 conidia plant‐ 1), and ‘Muscabac’ (25 g 1?1, 1 dl plant?1) reduced the number of pupae by 80%, 60% and 50%, respectively, as compared with untreated and chemical (isophenphos) controls. In 1990, M. anisopliae SF86–39 at rate 1.6 x 109conidia plant?1 and 1.5 x 108 CFU plant?1 and S. feltiae SFS‐22 (35000 plant?1), increased the yield of cauliflower 2.2, 1.8, and 2.3‐fold, respectively, as compared with the untreated control, but these yields were only 19%, 15% and 19% of those of the chemical (diazinon) control. Paecilomyces isolates were ineffective in the 1986 experiment in which they were included. Our results suggest that it is difficult to find efficient control agents among the fungal and nematode species tested for use as biopesticides against cabbage root flies, but that the potential of M. anisopliae against these pests deserves further study. 相似文献
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23个欧美杨无性系苗期叶锈病抗性测定 总被引:2,自引:0,他引:2
以引进23个欧美杨无性系为研究对象,通过对苗木叶锈病感病指数的调查,借助SPSS统计软件对调查数据进行统计分析,结果表明:对叶锈病的抗性表现超过对照品种I108的有19个,其中02-36-1、02-36-4、N177、N197和N195这5个无性系对叶锈病完全免疫;无性系02-34-334对叶锈病表现为高度抗病;02-01-119、324、03-04-111、03-04-97和02-34-278表现为抗病;03-04-141、03-04-170、02-34-347和03-05-184表现为感病;02-01-219、03-04-167、03-04-288和02-34-228表现为高感;对叶锈病的抗性表现不及对照品种I108的有3个,即03-05-206、03-04-171和03-05-156,均表现为高感。 相似文献
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The morphological basis of resistance to the whiteflyBemisia tabaci Genn. (Aleyrodidae: Hemiptera) was studied. The plant characters examined were leaf area, thickness of leaf lamina, hair
density, hair length, angle of insertion of leaf hair, and density of gossypol glands. Hair density and leaf thickness were
positively correlated with the population ofB. tabaci, and a positive correlation was obtained between the adult whitefly population and gossypol glands on stem internodes. Cotton
genotype USA-22 (sparsely hairy) was found to be more tolerant toB. tabaci than was genotype USA-13 (velvety hairy). The use of thinner and glabrous leaved cotton varieties is suggested to minimize
the whitefly menace in cotton. 相似文献
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在实验室内用5%增效浏阳霉素乳油1000倍液防治截形叶螨,24小时后的死亡率为95.5%。对三氯杀螨醇有较强抗性的二斑叶螨和朱砂叶螨,48小时后的死亡率也达90%左右。浏阳霉素对3种叶螨均无杀卵作用,但施药5~6天后,对初孵幼螨仍能杀死90%以上。低温能降低浏阳霉素的药效。在温室中施药一周后。对二斑叶螨的雌成螨无残效,但幼螨和前若螨的死亡率可达97.4%。以磷酸兰苯酯作增效剂的浏阳霉素比亚磷酸三苯酯作增效剂的药效好。在同一剂量下,对二斑叶螨的死亡率分别为98.2%和53.4%。5%浏阳霉素的1000倍液对智利植绥螨成螨的生存率、在叶上的定居率及着卵量均无影响。在温室栽培月季上喷药1次防治二斑叶螨,36天后防治效果仍保持在99%,而用三氯杀螨醇和敌敌畏防治,施药一周后需再次防治。 相似文献
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本研究在室内用“沙埋法”比较了两种斯氏属昆虫病原线虫Steinernema sp.(CB-2Y)和S.feltiae Agriotos对桃小食心虫的侵染力,结果表明CB-2Y线虫对桃小食心虫幼虫和冬茧的侵染力都高于Agriotos线虫。接线虫笫7天桃小食心虫LD50,CB-2Y组为49条线虫,而Agriotos组为158条;冬茧的LD50分别为1330条和24046条。在桃小冬茧开始活动期(6月15日)分别施用两种线虫,一个月后检查桃小食心虫成虫羽化率,CB-2Y线虫的控制效果明显优于Agriotos,在1024条线虫/桃小食心虫冬茧时(75条/cm~2),越冬代桃小食心虫的羽化率分别为8.2%和29.2%。 相似文献
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