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111.
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The hatching and mortality response of 0- to 48-h-old eggs of field strains of the stored-product insects Cryptolestes ferrugineus (Stephens), Lasioderma serricorne (F) and Oryzaephilus surinamensis (L) following phosphine fumigation for 24, 48 or 120 h at 27 (+/- 2) degrees C was investigated. Hatching was delayed and reduced in the first few days in a phosphine-resistant strain of C ferrugineus that was treated with 2.0-7.0 mg litre(-1) doses for 48 h (5-80% mortality) and with 1.0-2.0 mg litre(-1) for 120 h (44-84% mortality). In both the exposures there were significant increases in hatching on later days when compared with the corresponding controls. Developmental delay was, however, not evident in susceptible strains of C ferrugineus, L serricorne and O surinamensis that were exposed to phosphine for 24 h. 相似文献
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为了解食蚊鱼Gambusia affinis对华南地区水生昆虫多样性的影响,在实验室条件下,以食蚊鱼栖境中有代表性的3种水生昆虫为猎物,研究食蚊鱼的捕食选择性.结果表明,在单捕食者-多种猎物作用系统中,当猎物密度较低时,食蚊鱼对不同猎物的捕食选择性差异不显著.但随猎物密度的增加,食蚊鱼对白纹伊蚊Aedes albopictus幼虫和蛹的捕食量明显增加,对摇蚊Chironomus kiiensis幼虫和蜉蝣Cloeon bengalense稚虫的捕食量下降.在单捕食者-2种猎物的作用系统中,在猎物比例相同的情况下,食蚊鱼更喜欢捕食白纹伊蚊幼虫;但是在猎物总数不变的情况下,改变猎物比例,对食蚊鱼总的捕食量影响不大.说明食蚊鱼喜欢捕食漂浮于水面上、会动的活体猎物,对死的或不动的猎物不敏感,且对蚊子幼虫具有明显的嗜好性. 相似文献
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[目的]研究基于ACO-SVM的粮虫特征提取,探讨粮虫特征提取的可行性。[方法]通过分析储粮害虫图像识别系统中的1个关键环节——特征提取,提出把支持向量机(Support vector machine,简称SVM)算法中交叉验证训练模型的识别率作为储粮害虫特征提取评价准则的1个重要因子,将蚁群优化算法(Ant Colony Optimization,简称ACO)应用于粮虫特征的自动提取。[结果]该算法从粮虫的17维形态学特征中自动提取出面积、周长等7个特征的最优特征子空间,采用参数优化之后的SVM分类器对90个粮虫样本进行分类,识别率达到95%以上。[结论]该研究表明蚁群优化算法在粮虫特征提取中的应用是可行的。 相似文献
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Marrubium vulgare (Lamiaceae) is a plant traditionally used for the treatment of diabetes in Algeria. Compositional analysis of the aqueous infusion revealed the presence of fifteen metabolites, all belonging to the class of polyphenols. Particularly, seven flavonoids have been detected, together with 5-caffeoylquinic (chlorogenic) acid in small amounts; the extract is dominated by the presence of a series of complex molecules, characterized as verbascoside (acteoside) derivatives. Concerning the anti-diabetic effectiveness a series of in vivo experiments were carried out on albinos Wistar rats. Diabetes was induced in the animals by intra-peritoneal injection of alloxane; they were treated twice a day with aqueous extract from aerial part infusion (100, 200 and 300 mg/kg body weight) and glibenclamide (5mg/kg body weight) for 15 days. Oral administration of 200 and 300 mg/kg body weight of aqueous extract the Marrubium vulgare induced an significant effect antidiabetic and antihyperlipidemic (dose-dependent effect). A decrease in blood glucose by 50% for the dose 100 mg/kg and more than 60% for doses 200 and 300 mg/kg, as well as a significant lowering of total lipids, triglycerides, and total cholesterol levels in treated animals, compared with diabetic controls group (p<0.001), have been observed. Glibenclamide was used as reference and showed similar effects. 相似文献
119.
Insects respond to changes in microhabitat caused by canopy disturbance, and thus can be used to examine the ecological impacts of harvesting. Single-tree selection harvesting is the most common silvicultural system used to emulate local small-scale natural disturbance and maintain uneven-aged forest structure in temperate forests. Here, we test for differences in richness, abundance, and composition of hymenopteran and saproxylic insect assemblages at four different taxon levels (selected insect orders; and all hymenopteran families, and braconid subfamilies and morphospecies) between the canopy and understory of unharvested and single-tree selection harvested sites in a northern temperate forest from central Canada. Harvesting had no effect on insect assemblage richness, composition or abundance at the three highest taxon levels (order, family and subfamily). Similarly, richness and abundance at the lowest-taxon level (braconid morphospecies) were similar, although composition differed slightly between unharvested and harvested stands. Insect assemblages were vertically stratified, with generally higher abundance (for Diptera, Hymenoptera, some hymenopteran families and braconid subfamilies) and richness (for braconid morphospecies) in the understory than the canopy. In particular, composition of the braconid morphospecies assemblage showed relatively low similarity between the understory and canopy. Single-tree selection harvesting appears to influ-ence wood-associated insect taxa only subtly through small changes in community composition at the lowest taxon level, and thus is recommended as a conservative approach for managing these northern temperate forests. 相似文献
120.
电子鼻在储粮害虫检测中的应用研究 总被引:9,自引:0,他引:9
通过采用法国生产的Alpha MOS Fox3000电子鼻和自行设计的实验系统,分别对含有活的储粮害虫气体样本、含有死虫的气体样本和标准空气样本进行了检测与比较,并应用主元素分析法进行了模式识别.结果表明,无论虫量多少、虫子死活,它们的气体样本与标准气体样本都有明显的差异,从而能快速检测出粮食是否受到害虫的侵蚀. 相似文献