首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
3.
Abstract. The biological and taxonomic relationships of the braconid genera Cantharoctonus Viereck, Noserus Foerster, Pseudavga Tobias and Rhysipolis Foerster are briefly discussed and short diagnoses are given for each genus. Figures are provided of the type-species of each of the genera. Pachystigmus Hellén 1927 is a new synonym of Noserus Foerster, 1862.  相似文献   

4.
5.
Meiotic karyotypes were studied in males of Craspedolepta sonchi (Foerster, 1848), Diaphorina chobauti Puton, 1898, D. lamproptera Burckhardt, 1981, Psylla hartigii Flor, 1861, Cacopsylla palmeni (Loew, 1878), C. hippophaes (Foerster, 1848), C. melanoneura (Foerster, 1868), C. pyricola (Foerster 1848), C. moscovita (Andrianova, 1848), Bactericera salicivora (Reuter, 1876), Trioza abdominalis Flor, 1861, T. lauri = Lauritrioza alacris (Flor, 1861). Karyotypes were 2n = 25 (24 + XO) in all species except B. salicivora with 2n = 26 (24 + neo-XY). Testes consisted of two follicles each in all species but P. hartigii with four-follicular testes in males. The discussion covers the problems of chromosome numbers, sex-determining chromosome systems, B-chromosomes, patterns of C-banding, testis structure, and spermatid development in Psylloidea.  相似文献   

6.
Abstract A key is given to the world genera of the chalcidoid family Aphelinidae. Forty-four genera are accepted as valid, including three described as new, Encarsiella (type-species E.noyesi sp.n.), Hirtaphelinus (type-species H.smetanai sp.n.) and Samariola (type-species S.camerounensis sp.n.). The key is followed by a synopsis of the world genera, which includes: (1) citations of valid genera and their synonyms in chronological order; (2) total or approximate number of described species; (3) distribution in the six zoogeographical regions; (4) references mainly to major works and revisions; and (5) comments, especially on the new synonymies introduced in the present paper. The following new synonymies are proposed (the senior synonyms (valid names) are noted in parentheses): Aleurodiphilus DeBach & Rose ( Encarsia Foerster); Aneristus Howard, Ataneostigma Girault, Heptacritus De Santis ( Coccophagus Westwood); Artas Howard (Pteroptrix Westwood); Plastocharella Girault, Turmidiscapus Girault ( Centrodora Foerster); Encyrtophyscus Blanchard, Physculus Jasnosh, Physcus Howard ( Coccobius Ratzeburg); Mesidia Foerster ( Aphelinus Dalman); Paranthemus Girault ( Cales Howard); Primaprospaltella DeBach & LaSalle ( Coccophagoides Girault). The following genera are regarded as of doubtful position: Mesopirene Girault, Neocales Risbec, Paulianaphelinus Risbec and Verekia Risbec.  相似文献   

7.
This paper investigates the stability of the power-law steady state often observed in marine ecosystems. Three dynamical systems are considered, describing the abundance of organisms as a function of body mass and time: a “jump-growth” equation, a first order approximation which is the widely used McKendrick–von Foerster equation, and a second order approximation which is the McKendrick–von Foerster equation with a diffusion term. All of these yield a power-law steady state. We derive, for the first time, the eigenvalue spectrum for the linearised evolution operator, under certain constraints on the parameters. This provides new knowledge of the stability properties of the power-law steady state. It is shown analytically that the steady state of the McKendrick–von Foerster equation without the diffusion term is always unstable. Furthermore, numerical plots show that eigenvalue spectra of the McKendrick–von Foerster equation with diffusion give a good approximation to those of the jump-growth equation. The steady state is more likely to be stable with a low preferred predator:prey mass ratio, a large diet breadth and a high feeding efficiency. The effects of demographic stochasticity are also investigated and it is concluded that these are likely to be small in real systems.  相似文献   

8.
In all organisms, phenotypic variability is an evolutionary stipulation. Because the development of poikilothermic organisms depends directly on the temperature of their habitat, environmental variability is also an integral factor in models of their phenology. In this paper we present two existing phenology models, the distributed delay model and the Sharpe and DeMichele model, and develop an alternate approach, called the Extended von Foerster model, based on the age-structured McKendrick-von Foerster partial differential model. We compare the models theoretically by examining the biological assumptions made in the basic derivation of each approach. In particular, we focus on each model’s ability to incorporate variability among individuals as well as variability in the environment. When compared against constant temperaturemountain pine beetle (Dendroctonus ponderosae Hopkins) laboratory developmental data, the Extended von Foerster model exhibits the highest correlation between theory and observation.  相似文献   

9.
寄生伊藤厚丝叶蜂的恩姬蜂属一新种:膜翅目:姬蜂科   总被引:4,自引:0,他引:4  
本文报道了寄生伊藤厚丝叶蜂Pachynematus itoi Omutani的姬蜂科Icheumonidae 一新种:辽宁恩姬蜂Endasys liaoningensis。模式标本保存在林业部森林病虫害防治总站。  相似文献   

10.
平腹茧蜂亚科DirrhopinaevanAchterberg及平腹茧蜂属DirrhopeFoerster系中国分布新记录。本文描述该属 1新种 :绍氏平腹茧蜂Dirrhopeshawi。新种模式标本存于福建农业大学益虫研究室。  相似文献   

11.
许维岸  何俊华 《昆虫学报》2002,45(Z1):99-102
 记述采自辽宁、宁夏、新疆、浙江和贵州的侧沟茧蜂属Microplitis Foerster 二新种:宽背侧沟茧蜂M. amplitergius sp.nov.和内弯侧沟茧蜂M. incurvata s p.nov.。模式标本保存在浙江大学植物保护系昆虫标本室。  相似文献   

12.
侧沟茧蜂属二新种记述(膜翅目,茧蜂科)   总被引:1,自引:0,他引:1  
记述了采自福建武夷山、浙江(龙王山、百山祖)、湖北神农架、山东崂山和黑龙江镜泊湖等地的侧沟茧蜂属Microplitis Foerster 2新种。两色侧沟茧蜂Microplitis bicol-oratus sp.nov.(♀)和长径侧沟茧蜂Microplitis longiradiusis sp.nov.(♀)。两色侧沟茧蜂Microplitis bicoloratus与M.obscuripennis Xu and He相似,但以下特征与之区别:1)前后单眼间距与单眼直径等长(后者小于单眼直径);2)中胸盾片具一宽而深的中纵沟,且内具小脊(后者无中纵沟);3)后翅后小脉直(后者明显弯向翅基);4)翅半透明,淡烟褐色,前翅翅痣下方具一暗色斑(后者翅不透明,一致暗烟褐色);5)后足胫节中部具1黄白色环(后者为一致黑色)。采自福建、浙江、湖北和山东。长径侧沟茧蜂Microplitis longiradiusis与M.marshalli Kokujev相似,但以下特征与之区别:1)后单眼间距与单复眼间距等长(后者短于单复眼间距);2)腹部第2~3背板红黄色(后者黑色);3)后足基节红黄色(后者黑色);4)前翅r脉短于2-SR脉(后者与2-SR脉等长);5)前翅1-R1脉特别短,约与翅痣等长(后者明显长于翅痣长)。采自黑龙江。本文附中国侧沟茧蜂属种类检索表。模式标本均保存在浙江大学植保系寄生蜂标本室。  相似文献   

13.
本文报道长凹蜂姬属Diaparis Foerster 1新种:栗雪片象长凹姬蜂Diaparis niphadoctonus He,sp.nov.。模式标本存浙江农业大学应用昆虫研究所。  相似文献   

14.
Abstract The subfamily Dirrhopinae van Achterberg and the genus Dirrhope Foerster (Hymenoptera: Braconidae), both are recorded for the first time from China. Dirrhope shaxvi is also reported new to science in this paper. Type specimens of this new species are kept in the Beneficial Insects Lab, Fujian Agricultural University, Fuzhou, China.  相似文献   

15.
角姬蜂属一新种(膜翅目:姬蜂科)   总被引:3,自引:0,他引:3  
樊尚仁  盛茂领 《昆虫学报》1997,40(2):210-211
角姬蜂属CosmoconusFoerster,1868隶属柄卵姬蜂亚科Tryphoninae[1]、柄卵姬蜂族Tryphonini。迄今为止,全世界已知23种,其中东洋区1种,古北区13种,新北区9种。我国已知3种[2,3]:中国角姬蜂C.chinensisKasparyan,1973分布于西藏;中角姬蜂C.meridionatorAubert,1963分布于内蒙古及欧洲;西藏角姬蜂C.tibeticusKasparyan,1971分布于西藏和甘肃。属征:前翅第2脉在中央上方强度锯齿形曲折;额中央有一个角状突或乳状突。本文报道来自沈阳的本属一新种。模式标本保存在林业部森林病虫害防治总站。沈阳角姬问Cosm。sshenyangensi…  相似文献   

16.
A new subgenus of the genus Schizoprymnus Foerster is described and figured from Honshu, Japan. The subgenus, Ibarakius subgen. nov., comprises three species, S. (I.) gotoi sp. nov. (type species), S. (I.) kaizawus sp. nov., and S. (I.) honshuensis sp. nov. A pair of long, curved posteroventral processes on the carapace is unique to Ibarakius subgen. nov. The variability of frontal protuberances and sutures of the carapace in the brachistine genera Triaspis Haliday and Schizoprymnus Foerster is discussed.  相似文献   

17.
On two occasions in August 1979, massive aerial swarms of Lasius alienus (Foerster) (Hymenoptera: Formicidae) occurred over Castle Lake, California. Each event resulted in the delivery of millions of ants to the lake surface. Consumption and subsequent excretion by fish, in addition to direct release from ants, produced a brief, but marked increase in water column ammonium levels. Castle Lake phytoplankton are often nitrogen limited and possess a high affinity for ammonium. The events and effects are described and discussed with respect to nutrient limitation in an unproductive ecosystem.  相似文献   

18.
Liu JX  Chen HY  Xu ZF 《ZooKeys》2011,(108):49-60
The Chinese species of the genus Ismarus Haliday, 1835, are revised for the first time. Three new species from the Oriental region of China and belonging to Ismarus halidayi-group are described and illustrated: Ismarus longussp. n., Ismarus nigritrochantersp. n. and Ismarus parvicellussp. n. Two species are newly reported for the Chinese fauna: Ismarus dorsiger (Haliday, 1831) and Ismarus halidayi Foerster, 1850. A key to the Chinese species of the genus is provided. The type specimens are deposited in the Hymenopteran Collection of South China Agricultural University, Guangzhou (SCAU).  相似文献   

19.
This paper investigates the dynamics of biomass in a marine ecosystem. A stochastic process is defined in which organisms undergo jumps in body size as they catch and eat smaller organisms. Using a systematic expansion of the master equation, we derive a deterministic equation for the macroscopic dynamics, which we call the deterministic jump-growth equation, and a linear Fokker–Planck equation for the stochastic fluctuations. The McKendrick–von Foerster equation, used in previous studies, is shown to be a first-order approximation, appropriate in equilibrium systems where predators are much larger than their prey. The model has a power-law steady state consistent with the approximate constancy of mass density in logarithmic intervals of body mass often observed in marine ecosystems. The behaviours of the stochastic process, the deterministic jump-growth equation, and the McKendrick–von Foerster equation are compared using numerical methods. The numerical analysis shows two classes of attractors: steady states and travelling waves.  相似文献   

20.
Abstract The species of the genus Syntretus Foerster form China are revised in this paper. Five species are recognized with one species, Syntretus longitergitus sp. nov., as new to science. A key to the Chinese species fo this genus is provided.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号