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21.
环螽属Letana Walker,1869(=Pyrrhicia Stal,1873)迄今已知22种,分布中国、越南、泰国、缅甸、尼泊尔、印度和斯里兰卡等国。作者在整理这个属的标本时发现2新种和1新纪录种,分别采自中国(西藏)和尼泊尔,现记述于后。模式标本均保存在中国科学院上海昆虫研究所。 相似文献
22.
绿褶托菇在我国首次发现 总被引:2,自引:2,他引:0
本文报道我国蘑菇科Agaricaceae的一个新记录种——绿褶托菇Clarkeinda trachodes (Berk.)Singer,该种所隶属的绿褶托菇属Clarkeinda O. Kuntze现知是个分布于热带亚洲的单型属。 相似文献
23.
小竹鼠在我国仅分布于云南西部热带亚热带地区。主要生活于山坡稀树灌丛、阔叶林、橡胶园及居民点附近。在盈江县分布于海拔300-950米地带。取食、休息、繁殖主要在洞道内。洞系由洞口、取食道、趋避道、窝及“厕所”组成。食物主要有棕叶芦、芦竹及三叶橡胶等18种,尤喜食橡胶树主根,因而对橡胶树危害很大。13号标本中雌7雄6。在盈江每胎2-3只,以2只为多。成年小竹鼠过独居生活,雌雄各有自己的洞系。 相似文献
24.
The long-distance migration of Nilaparvata lugens (Stål) (Delphacidae) in China: radar observations of mass return flight in the autumn 总被引:1,自引:0,他引:1
J. R. RILEY CHENG XIA-NIAN ZHANG XIAO-XI D. R. REYNOLDS XU GUO-MIN A. D. SMITH CHENG JI-YI BAO AI-DONG ZHAI BAO-PING 《Ecological Entomology》1991,16(4):471-489
Abstract.
- 1 A case study is presented of the autumn migration of the brown planthopper, Nilaparvata lugens (Stål), in the area of Nanjing in the People's Republic of China. The study was made using a high frequency (8 mm wavelength) radar and a net suspended from a kytoon.
- 2 The observations confirmed that long-distance return migrations occur in China in mid and late September, with N.lugens being carried on the prevailing north-easterly wind towards the autumn infestation and overwintering areas of the species.
- 3 After mass take-off in the late afternoon or at dusk, the migrants flew for several hours during the evening, often in a dense layer which formed at heights between about 400 and 1000m above ground. These layers often had well-defined ceilings corresponding to an air temperature of about 16°C. The migration height was above the top of the surface temperature inversion, i.e. the migrants did not fly at the height of the warmest air.
- 4 The dense layer concentrations overflying the radar were backtracked to source areas up to 240 km away in the north-east of Jiangsu Province. Planthoppers observed emigrating from the Nanjing area would reach areas in south Anhui Province or north Jiangxi Province if they flew for 12 h.
- 5 There was a second period of mass take-off at dawn. Insect layers sometimes formed but did not last longer than 1–2h.
- 6 The present results were strikingly different from those previously observed in the dry season in the Philippines, where migratory flight durations were largely confined to periods of about 30min at dusk and dawn.
- 7 Our observations are discussed in relation to the equator-wards return migrations undertaken in autumn by other insect species, and the importance of these migrations for the maintenance of long-flying genotypes in the overwintering populations is considered.
25.
Spatial patterns and feeding of meiobenthic harpacticoid copepods in relation to resident microbial flora 总被引:2,自引:2,他引:0
Distributional and feeding relationships of harpacticoid copepods and their microbial prey were examined in a tidal channel at Great Sippewissett Marsh. A horizontal zonation of photosynthetic microorganisms was composed of: 1) a diatom area; 2) a purple sulfur bacterial (Thiocapsa sp.) area; and 3) a clear area. Four species of harpacticoid copepods were associated with given areas. Leptocaris brevicornis occurred in very high densities in the diatom area but in relatively low densities in other areas. Mesochra lilljeborgi occurred in significantly higher densities in the purple and clear areas.Feeding experiments, using resident microbial flora labelled with NaH14CO3 and 3H-thymidine, were conducted to determine which foods are 1) ingested but simply pass through the gut and 2) ingested, and retained. These experiments indicated that L. brevicornis ingested diatoms and the heterotrophs associated with the diatoms, but only retained the heterotrophic portion. Microscopic examination indicated that diatoms were passed out intact in feces. Oscillatoria sp. (cyanobacterium) was not ingested. Mesochra lilljeborgi ingested Spirulina sp. (cyanobacterium), Thiocapsa sp., and the heterotrophs associated with Thiocapsa but only retained the Thiocapsa label.These data for harpacticoids suggest that spatial distributions of meiofauna may be closely coupled with microbial food organisms which they consume. Also, that while several microbial foods may be ingested, only certain microbes are digested and assimilated as a food resource, further indicating the complexity of feeding relationships among the meiofauna. 相似文献
26.
本文对扁头中国短头鲵(新属新种) (Sinobrachyops placenticephalus gen. et sp. nov.) 的形态特征和分类位置进行简述.标本得自著名的恐龙化石产地——自贡大山铺,产出时代为中侏罗世.中国短头鲵是目前迷齿类中在地史上最年轻的一个属.它的发现使迷齿类在地球上生存时代的上限推移到中侏罗世. 相似文献
27.
THE FLORA AND VEGETATION OF BRITAIN: ECOLOGY AND CONSERVATION 总被引:3,自引:3,他引:0
C.D. PIGOTT 《The New phytologist》1984,98(1):119-128
28.
C. G. G. J. VAN STEENIS 《Botanical journal of the Linnean Society. Linnean Society of London》1984,89(4):289-292
From the altitudinal ranges of species recorded for the Malesian mountain flora, in Flora of Java and the 6 or so volumes of Flora Malesiana it was concluded that there are critical altitudes where the floristic composition shows rather abrupt demarcations, namely at 1000, 1500, 2400 and 4000 m altitude. In a generalized way this also holds for the structure and stature of the vegetation. For cultivated plants the altitudes of 1000 and 1500 m are also distinct demarcations. 相似文献
29.
湖北蕨类植物区系基本成分和主要特点的探讨 总被引:14,自引:2,他引:12
在湖北蕨类植物区系中,属种数量最多的科有水龙骨科(Polypodiaceae)、鳞毛蕨科(Dryopteridaceae)和蹄盖蕨科(Athyriaceae)。并以鳞毛蕨属(Dryopteris)、耳蕨属(Polystichum)和蹄盖蕨属(Athyrium)为最主要代表。区系的主要特点为:种类丰富,地理成分错综复杂,联系广泛,显示出多种区系成分交叉在一起的过渡特色。 相似文献
30.
十余年来,广东、河南、陕西等省均报告有形态特殊的间日疟原虫存在,并曾被命名为间日疟原虫多核亚种(Plasmodium vivax multincleatum)(江静波等,1965),或称为变异的间日疟原虫(张奎等,1980),以上命名均是以疟原虫红内期的形态特征为依据,其在蚊体内的发育特征如何,则尚缺乏报告。1979年我们曾初步观察了该虫在蚊体内的发育情况(江静波等,1980),于后,1980年又对该种疟原虫在中华按蚊体内的发育情况进行了较系统的观察,现将结果报告如下: 相似文献