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1.
灭幼脲引致蚊虫畸形的扫描电镜观察   总被引:2,自引:0,他引:2  
仇序佳 《昆虫学报》1989,32(1):127-128
目前对有害昆虫以灭幼脲Ⅰ号的效果最好,它是一种昆虫生长调节剂。它与一般的化学杀虫剂不同,根据目前国外资料的报道,其杀虫作用主要是抑制昆虫表皮几丁质的合成,使昆虫的生长发育和变态受到阻滞而死亡。本文报道灭幼脲Ⅰ号对致倦库蚊和骚扰阿蚊引起形态变化的扫描电镜及组织学观察结果。  相似文献   

2.
蝮蛇抗拴酶(清栓酶)现已广泛应用于治疗老年病,特别是心脑缺血性疾病等。它对细菌的作用未见有报道。本文总结了不同浓度的清栓酶的抗菌试验。其结果均不敏感,现报道如下。  相似文献   

3.
尹履鑫  岳永生 《遗传》1980,2(3):26-27
青岛来航鸡有着悠久的历史,为了进一步 提高它的生产性能,我们对它的四个主要经济 性状的遗传特性进行了研究,并参考有关报道 资料制定了新的选种方法。  相似文献   

4.
龙眼蚁舟蛾Stauropus alternus Walker属鳞翅目舟蛾科。近年来,在海南岛文昌县沿海木麻黄林中猖獗为害。它是蚁舟蛾属中首次发现大发生的害虫。关于其为害及生物学特性方面的资料,国内外少见报道。为了及时防治,确保林木的正常生长,1976—1978年于海南岛国营岛东林场对它进行了研究,现将结果报道如下。  相似文献   

5.
楔桥弯藻属(Gomphocymbella)是由Mueller在1905年建立的,它兼有桥弯藻属和异极藻属的双重特性。虽然对它的系统发育及分类问题仍在讨论之中,但一般把它归于异极藻科中。它较为罕见,至今报道的种类仅有10个左右。在我国至今只报道有一个种。近几年来,对湖北省硅藻类中的异极藻科(Gomphomenaceae)进行了分类学研究,发现有3个楔桥弯藻属的种类,其中2个为新种类:疏纹楔桥弯藻(Gomphocymbella laxistria Shi et N.Li)和不对称楔桥弯藻(G.asymmetrica Shi et N.Li);另一个种为我国首次报道的新记录:波润楔桥弯藻(G.brunii(Fricke)O.Mailer)。  相似文献   

6.
安徽省黄山啮齿类区系研究   总被引:1,自引:0,他引:1  
黄山是我国著名的风景区之一,为国内外游览胜地。黄山由于它山深林密、地势复杂,虽蕴藏着丰富的动植物资源,但过去一直对它缺乏全面调查。盛和林等虽均报道过一些黄山  相似文献   

7.
近年来,对尾核的感觉机能逐渐有所了解。曾有人报道,尾核头部表层对于丘脑丘外系单位活动有选择性的压抑作用,提示它可能在疼痛信息的整合中起一定作用。不久就有人观察到电解损毁家兔尾核头部后,针刺镇痛效应减弱,而刺激它时,针效加强。文献上报道,尾核头部前、后不同区域的结构并不完全相同。这种结构上的  相似文献   

8.
神奇的辣木与人类生活   总被引:1,自引:0,他引:1  
辣木在印度、非洲热带地区民间利用已久。它含有丰富而惊人的营养成分,在欧美工业发达国家,人们已将辣木视为新时代健康的食物来源,我们对它的认识还很不够。现将一些资料综合报道,供有关方面参考。  相似文献   

9.
长春净月潭地区土壤跳虫的生态分布   总被引:9,自引:1,他引:8  
陈鹏  田中真悟 《昆虫学报》1990,33(2):219-226
土壤动物直接参与土壤形成,它与土壤微生物的相互配合,对植物凋落物的分解起着十分重要的作用。土壤跳虫是土壤动物中最重要的类群之一。关于它的生态分布,目前国内报道不多。东北师范大学和日本九州大学合作,对长春净月潭地区的土壤跳虫进行了初步调查。  相似文献   

10.
硝酸还原酶(以下简称 NR)是高等植物氮素代谢的关键酶,对体内其他代谢也有着重要的影响。最近,我们已报道NR活力能促进ATP的形成。本文则研究了ATP对NR活力的影响。由于外源ATP不有直接进入细胞内,难以观察它对体内NR活力的影响,因此只对它对体外NR活力的影响及其机制进行了研究,并把它与ADP、AMP的影响加以比较。  相似文献   

11.
János Török 《Ecography》1990,13(4):257-264
Food composition, prey size utilization and foraging behaviour of three sympatric woodpecker species ( Dendrocopos major, D. medius, D. minor ) were studied in an oak forest near Budapest during the breeding season in 1983 and 1984. Considering these three aspects of feeding, the great spotted woodpecker is a generalist species. Food composition of this species resembled the arthropod supply on the bark of trees more than those of the other two species. The bark of the trees seems to be a relatively unproductive microhabitat in the breeding season, so woodpecker species use, to different degrees, the food supply of the foliage as well. The food and the foraging behaviour of the middle spotted woodpecker show that this species feeds on prey living both on barks and in the foliage; it occupies-an intermediate position between the great and the lesser spotted woodpeckers. Prey size did not correlate with predator size suggesting that woodpeckers adapted not to the summer resources but rather the winter ones.  相似文献   

12.
During winter and spring the oak Quercus robur , was the tree species most utilized by middle spoiled woodpeckers. In March, saptrees, mainly maples Acer platanoides , were preferred for a short period. In winter the birds foraged in the crowns of oaks but in spring they preferred lower stem parts. Dead branches were utilized more in winter than in spring. The birds mostly used a gleaning and probing technique, which may render the species more senstitive to severe weather conditions than other woodpecker species. Arthropods collected from trees were mostly spiders, beetles, thrips or springtails. The nestlings were mainly fed on scale insects and larvae of moths and sawflies. The oak habitat specialization is believed to be caused by competition for food with other gleaning forest birds. Food shortage might possibly occur during periods of bad weather, causing increased mortality.  相似文献   

13.
光肩星天牛Anoplophora glabripennis(Motsch.)是我国重要林木蛀干害虫,造成了巨大的经济损失(张星耀、骆有庆,2003)。大斑啄木鸟Picoides major(L.)是林业蛀干类害虫的重要天敌,关于啄木鸟对蛀干类害虫的控制作用国内已有一些报道,  相似文献   

14.
Standing dead trees may be a limited resource for woodpeckers in managed forests, especially for species that rely on dead wood for their nest or roost cavity, and as foraging sites. Effective conservation strategies for woodpeckers require a detailed knowledge of species’ responses to dead wood availability. To investigate the importance of standing dead wood (snags) for the abundance and nest-site use of the great spotted woodpecker Dendrocopos major and middle spotted woodpecker Leiopicus medius in mature riverine forests, we compared the responses of birds between two periods—before mass mortality, and during a pulse in standing dead trees. The density of standing dead trees available for cavity excavation by the great spotted woodpecker and the middle spotted woodpecker increased significantly during the study period: 37-fold and 4-fold, respectively. Temporal trends in the abundance of both woodpecker species from 2000 to 2015 were not significant. Great spotted woodpeckers were significantly more likely to use dead trees and places with wounds in species other than oak and ash during the outbreak period than in the pre-outbreak period. Middle spotted woodpeckers were significantly less likely to excavate cavities in tree species other than oak and ash in the outbreak period, but dead trees were more likely selected. An interspecific comparison suggests that the probability of a nest-hole having been excavated by a middle spotted woodpecker increased with a nest-hole sited in ash, in a dead tree, in a limb/branch, and decreased with a nest-hole in a closed forest. These findings suggest that woodpecker species, especially weak excavators, may benefit from an increase in dead wood availability leading to nest niche shifts into more favorable substrates for cavity excavation. However, a strong increase in dead wood availability does not modify the general pattern of niche partitioning between great spotted and middle spotted woodpeckers. Conservation plans for the specialized middle spotted woodpecker must consider the preference for dead and decaying trees. The decreasing number of large ashes and oaks, and the lack of natural regeneration of the latter species, may negatively affect the middle spotted woodpecker in the future.  相似文献   

15.

Species are often arranged along a continuum from “specialists” to “generalists”. Specialists typically use fewer resources, occur in more patchily distributed habitats and have overall smaller population sizes than generalists. Accordingly, the specialist-generalist variation hypothesis (SGVH) proposes that populations of habitat specialists have lower genetic diversity and are genetically more differentiated due to reduced gene flow compared to populations of generalists. Here, expectations of the SGVH were tested by examining genetic diversity, spatial genetic structure and contemporary gene flow in two sympatric woodpecker species differing in habitat specialization. Compared to the generalist great spotted woodpecker (Dendrocopos major), lower genetic diversity was found in the specialist middle spotted woodpecker (Dendrocoptes medius). Evidence for recent bottlenecks was revealed in some populations of the middle spotted woodpecker, but in none of the great spotted woodpecker. Substantial spatial genetic structure and a significant correlation between genetic and geographic distances were found in the middle spotted woodpecker, but only weak spatial genetic structure and no significant correlation between genetic and geographic distances in the great spotted woodpecker. Finally, estimated levels of contemporary gene flow did not differ between the two species. Results are consistent with all but one expectations of the SGVH. This study adds to the relatively few investigations addressing the SGVH in terrestrial vertebrates.

  相似文献   

16.
同域分布3种啄木鸟冬季取食的生态位差异   总被引:1,自引:0,他引:1  
戎可  司雨蕙  潘麒嫣  王欢 《生态学报》2018,38(23):8314-8323
为了掌握黑啄木鸟、三趾啄木鸟和大斑啄木鸟的冬季取食行为特征,特别是三者之间取食生态位的差异,于2016年1月5-13日,在黑龙江省凉水国家级自然保护区以样线法结合样方法对3种啄木鸟的取食生境和取食行为进行了系统调查,收集了15个生境和行为特征变量数据。共布设45条样线,484个对照样方,收集312组啄木鸟取食数据,其中黑啄木鸟73组,三趾啄木鸟97组,大斑啄木鸟142组。多变量回归树和多分类逻辑斯谛分析结果显示,3种啄木鸟在所调查的15项特征上存在显著分异。采用基于利用-可利用方法的Bailey''s方法和双因子方差分析,分别对3种啄木鸟的生境选择和行为特征进行分析,结果显示:黑啄木鸟和三趾啄木鸟偏好在郁闭度较高的原始云、冷杉林中取食,而大斑啄木鸟则随机地在各种林型、生境中取食。黑啄木鸟、三趾啄木鸟多在树干取食,黑啄木鸟更常在倒木上取食,而大斑啄木鸟则多在树冠层取食。黑啄木鸟基本只在主干上凿洞,其他两种特别是大斑啄木鸟则可以在侧枝上取食。与黑啄木鸟和大斑啄木鸟凿洞取食昆虫不同,三趾啄木鸟多通过扒去树皮获得食物。黑啄木鸟的取食树基本为死树,单树取食时间最长,大斑啄木鸟多在活树上取食,单树取食时间最短,经常更换取食树,而三趾啄木鸟的取食树则死活参半,单树取食时间也较长。黑啄木鸟的冬季取食行为节律表现为双峰形,日出后和日落前各有一个活动高峰,其他两种则于白天持续取食。3种啄木鸟取食生境和行为生态位的差异,使它们能够更有效地利用有限的食物资源,共存于同一森林。  相似文献   

17.
Land use change is a major threat to global biodiversity. Forest species face the dual threats of deforestation and intensification of forest management. In regions where forests are under threat, rural landscapes that retain structural components of mature forests potentially provide valuable additional habitat for some forest species. Here, we illustrate the habitat value of traditional wood pastures for a woodpecker assemblage of six species in southern Transylvania, Romania. Wood pastures are created by long-term stable silvo-pastoral management practices, and are composed of open grassland with scattered large, old trees. Because of their demanding habitat requirements, woodpeckers share habitat with many other bird species, and have been considered as possible indicator species for bird species diversity. We first compared woodpecker assemblages between forests and wood pastures. Second, we grouped features of wood pastures into three spatial contexts and addressed how these features related to the occurrence of three woodpecker species that are formally protected. Woodpecker species composition, but not the number of species, differed between forests and wood pastures, with the green woodpecker occurring more commonly in wood pastures, and the lesser spotted woodpecker more commonly in forests. Within wood pastures, the intermediate context (especially surrounding forest cover) best explained the presence of the grey-headed and middle spotted woodpecker. By contrast, variables describing local vegetation structure and characteristics of the surrounding landscape did not affect woodpecker occurrence in wood pastures. In contrast to many other parts of Europe, in which several species of woodpeckers have declined, the traditional rural landscape of Transylvania continues to provide habitat for several woodpecker species, both in forests and wood pastures. Given the apparent habitat value of wood pastures for woodpeckers we recommend wood pastures be explicitly considered in relevant policies of the European Union, namely the Habitats Directive and the EU Common Agricultural Policy.  相似文献   

18.
The Okinawa woodpecker Sapheopipo noguchii is the rarest extant woodpecker species. The monotypic genus Sapheopipo was considered to be a representative of an old lineage of woodpeckers that led to the Eurasian genera Picus and the Blythipicus–Gecinulus species. This view, based on similarities in color patterns, external morphology and foraging behavior, has been adopted in all major accounts of the family. The alternative view, that this woodpecker may be related to the widespread white-backed woodpecker Dendrocopos leucotos, which evolved distinctive subspecies on other East Asian islands, has not been generally accepted. We analyzed partial sequences of the mitochondrial cytochrome b (cyt b) gene to test these hypotheses. The data suggest that the Okinawa woodpecker is a member of the genus Dendrocopos, with white-backed woodpecker and great spotted woodpecker D. major as close relatives. Color patterns support the genetic results and indicate a closer relationship with the white-backed woodpecker. Consequently, the correct taxonomic designation of the Okinawa woodpecker would be Dendrocopos noguchii (Seebohm in Ibis 5(5):173–182, 1887) in the tribe Campetherini rather than Picini.This revised version was published online in February 2005 with corrections to tables 1 and 2.  相似文献   

19.
选取大斑啄木鸟、灰头绿啄木鸟、百灵鸟、山雀和戴胜鸟作为样本,其中百灵鸟、山雀和戴胜鸟作为对照,研究啄木鸟颅骨颞部、额部和枕部的显微结构参数.样本经Micro-CT扫描后,在断层扫描图像的基础上,可以得到的显微结构参数包括体积分数、结构模型指数、骨小梁数量、骨小梁厚度、骨小梁分离度和骨质密度.通过与其他鸟类的对比分析发现,啄木鸟具有更加独特的颅骨结构,其骨小梁厚度、体积分数和骨小梁数量显著高于其他鸟类,结构模型指数小于其他鸟类,其颅骨所具有的这种特点是啄木鸟长期进化过程中为适应啄木行为所形成的,也是其抗冲击的重要原因.  相似文献   

20.
The main goals of this study were to investigate the relationships between densities of the breeding population of the middle spotted woodpecker Dendrocopos medius obtained on 19 large-scale plots, and the share of different habitats and age of forest stands. An average crude density based on an area defined arbitrarily by observers was 0.66±0.43 territories/10 ha, while the ecological density based on an area including habitats potentially used by organisms reached 1.09±0.64 territories/10 ha. Stepwise multiple regression indicated that the crude density was negatively affected by the share of coniferous forest thereby explaining 50% of variation. The ecological density was negatively correlated with the percentage of young deciduous stands (0–40 years old). This variable explained 36% of the total variation. These results suggest that on the level of macrohabitat analysis, the share of unsuitable forest stands seem to play a major role in determining the density of the middle spotted woodpecker.  相似文献   

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