中国花蝇科及蝇科三新种一新亚种

本文记述中国花蝇科及蝇科三新种及一新亚种。除第二种外,各新种或新亚种模式标本均存上海昆虫研究所。 花蝇科 1.黑胸拟花蝇 Calythea atra Fan新种(图1,2) 体长4.0毫米。头黑色。眼:高约为长的1(1/2),有少数很微的毛。额最狭处间额消失,侧额如线,仅前方1/2长度内有额鬃,间额鬃长,间额及沿侧额鬃列一线黑色。头前面粉被略带银色的灰色。触角黑,第三节为第二节的1(1/2)倍,芒基部半段有很短的毳毛。侧颜裸,狭于触角第三节的宽,颜鬃长大,髭在口缘一线,口上片明显。颊高约为眼高     

四川西部蝇科三新种(双翅目：蝇科)

整理1979～1996年采自中国四川省西部的蝇类标本中,发现蝇科三新种：树棘蝇属 Potamia Robineau-Desvoidy, 1830一新种：鬃跗树棘蝇Potamia setitarsis sp. nov.; 胡蝇属 Drymeia Meigen,1826一新种：四川胡蝇Drymeia sichuanensis sp. nov; 池蝇属 Limnophora Robineau-Desvoidy, 1830一新种：灰黄池蝇 Limnophora cinerifulva sp. nov。模式标本存北京军事医学科学院医学昆虫标本馆。     

A NEW GENUS AND TWO NEW SPECIES OF COENOSIINI (DIPTERA: MUSCIDAE)

Abstract  A new genus Chouicoenosia and two new species C. recta and C. curva are described. The holotype of C. recta is deposited in the Department of Biology, Shenyang Normal College, and the rest of the type specimens are kept in the Institute of Zoology, Academia Sinica.     

中国四川蝇科八新种(双翅目)

本文报道中国四川地区产蝇科８新种。模式标本存北京军事医学科学院医学昆虫标本馆。     

秽蝇族一新属二新种(双翅目:蝇科)(英文)

本文记述秽蝇族一新属及二新种,即周秽蝇属Chouicoenosia gen. noyv. ,直叶周秽蝇C. recta sp. nov. 和弯叶周秽蝇C. Curva sp. nov. 。直叶周秽蝇的正模存于作者单位,其余模式标本存于中国科学院动物研究所。 新属的主要特征是:后倾上眶鬃1对;雄性额角呈直角;触角芒基半部羽状,端半部裸;复眼下后缘向前凹入;背中鬃1 3;小盾鬃两对;下腋瓣大于上腋瓣;中胫具2后背鬃;后胫具1前腹鬃、2前背鬃、2后背鬃。     

ISLAND POPULATIONS OF RODENTS: THEIR ORGANIZATION AND FUNCTIONING

1. Data from 14 confined populations living under natural conditions (mainly on small islands) and from a few laboratory populations have been used. 2. Several differences between a typical, confined rodent population (i.e. living under natural conditions in a well isolated, homogeneous and relatively small area) and an open one have been determined. 3. Island populations are characterized by: (a) Attainment and maintenance of high densities not observed at all, or recorded only periodically, in open populations of comparable species. (b) Stability of population numbers, expressed either by very slight fluctuations or by a very regular cycle with only small differences between peaks of consecutive years. (c) Lack of emigration resulting from any or all of the barriers surrounding the confined population, from homogeneity of the habitat enclosed by these barriers, or from a lower tendency to dispersal of individuals forming such populations. (d) Decreased reproduction. (e) Low losses of independent individuals. (f) Mortality of sucklings changing with the population density. (g) An age structure that is probably more differentiated and more regularly changing in an annual and long-term cycle. (h) Different spatial organization based on smaller home ranges, that are differently arranged in relation to one another from those in open populations; the arrangement of home ranges allows the population to squeeze in a greater number of individuals with possibly the lowest number of interactions between individuals. 4. In confined populations there must be different mechanisms for the regulation of numbers from those in open populations: (I) in the latter the regulation occurs by the outflow of the surplus of independent individuals, i.e. through the dispersal and high mortality of migrants; (2) in confined populations the inflow of independent individuals is regulated by controlled reproduction and early mortality of offspring. Both mechanisms are induced by social pressure but in the second case (regulation of inflow) a much stronger social organization is indispensable Only those species that are capable of the formation of such an organization can survive as confined populations. 5. Knowledge of phenomena occurring in confined populations is useful for predicting the fate of populations of different species which become isolated as a result of human activity in transforming and subdividing the natural environment.     

海南岛热带植物资源的演变和保护

植物区系及植物资源的演变与生态平衡的关系非常密切,且已引起人们愈来愈对它的注意。海南岛地处我国热带,其热带植物种类丰富、珍稀奇特,素为世人所仰注,惟长期以来,人类在生产生活活动中,未能完全改变那种“刀耕火种”、“畲田火米”的古老耕种方式和一些不合理的开垦、采伐措施。因而引起物种和资源及生态环境等受到一定的干扰影响,使它们随着森林植被的范围缩小而数量日益减少,甚至有些濒临绝灭,或局部地区出现生态系统失调现象。因此笔者提出希望国家应考虑在岛上增设不同生态群落类型的自然保护区或植物园,作为科学研究,物种保护,教学研究及科普的基地。     

ISLAND BIOGEOGRAPHY AND PALAEOBIOLOGY: IN SEARCH FOR EVOLUTIONARY EQUILIBRIA

1. The concept of evolutionary equilibrium has been derived from the theory of island biogeography via an ecological rationale for increase in species extinction rate and decrease in speciation rate with increasing diversity of the system.
2. This concept is theoretically plausible at the species level and at a regional scale but, in spite of several empirical tests in the fossil record, it has thus far remained unsupported by empirical evidence. In order to test it conclusively, one has to analyze not only the pattern of species number through time but also its relationship to speciation and species extinction rates; independent evidence for perturbations must also be available.
3. The concept of evolutionary equilibrium at the global scale must be extrapolated over higher levels of taxonomic hierarchy, for reliable species-level data are unavailable at this scale. A theoretical justification for this concept cannot, then, be derived from the theory of island biogeography.
4. The rates of family extinction and origination in the Phanerozoic show no evidence for diversity-dependence, which undermines most quantitative models of biotic diversification based on the concept of global evolutionary equilibrium. Rigorous testing of these models cannot be done at the present state of knowledge because of the uncertainty about the empirical pattern (sampling and taxonomic biases, absolute time scale).