A new species of Bryodema (Orthoptera : Acridoidea) from China, with a key to the described species

A new species Bryodema nigrofrascia of the genus Bryodema Fieber, 1853 (Orthoptera, Acridoidea, Acrididae Oedipodinae) from China is described. A key to known species of the genus is given. The type specimens are deposited in the Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xining, Qinghai.

A new genus and species of grasshopper from China (Orthoptera : Acrididae Catantopinae)

This paper reports a new genus and species of Catantopinae: Guizhouacris xiai gen et sp. nov. The new genus is similar to Genimen I. Bolivar, 1917, but differs from the latter in: 1) lateral lobes of metasternum separated in apical part and 2) prozona about 2.5 (male) and 2.7 (female) times longer than metazona. The new genus is also similar to Rhinopodisma Mishchenko, 1954 (= Aserratus Huang, 1981), but differs from the latter in: 1) diameter of tympanal aperture longer than half tergum and 2) face not projected between two eyes. Type specimens are deposited in the Museum of Hebei University ( MHU).

A new species of Saussurea (Asteraceae) from Tibet and its systematic position based on ITS sequence analysis

A new species of Saussurea, S. erecta S. W Liu, J. T Pan A J. Q. Liu sp. nov., is described from Tibet. It resembles S. kingii but may be distinguished by having distinct stems and glabrous achenes. Saussurea kingii was placed in sect. Pseudoeriocoryne of subgen. Eriocoryne; this section was circumscribed by acaulescence and an inflorescence with congested capitula surrounded by a rosette of leaves. The discovery of S. erecta with distinct stems, cauline leaves and corymbose capitula blurred the delimitation of sect. Pseudoeriocoryne and suggested that the section may be polyphyletic. Both the close relationship and the significant difference between S. erecta and S. kingii were confirmed by analyses of nrDNA ITS sequences. The resulting phylogenies based on ITS data further suggest that Saussurea sect. Pseudoeriocoryne, as traditionally defined, does not constitute a monophyletic group. The rapid radiation and speciation of Saussurea in the Qinghai-Tibetan Plateau, as inferred from ITS phylogeny, are discussed. (c) 2005 The Linnean Society of London.

Two new species of Leymus (Poaceae : Triticeae) from Qinghai, China

Two new species of Leymus, L. pendulus and L. obvipodus, are described and illustrated. These two species are endemic to Qinghai province, China, occurring at the margins of woodlands, wastelands, mountain valleys, and the bases of walls, at 2280-2400 m elevation. Leymus pendulus is unusual in its lax, long, pendent spikes. It is closely related to L. flexus, but differs from that species by pendent spikes, longer rachis internodes, and shorter glumes and lemmas. Leymus obvipodus is unique in the genus in having all spikelets pedicellate. It resembles both L. divaricatus (Drobow) Tzvelev and L. aristiglumus L. B. Cai but differs from the former by lanceolate glumes with 1 to 3 nerves, longer spike-like panicles, taller culms, and lanceolate lemmas with 5 obscure nerves and pubescent margins, and from the latter by lax, longer spike-like panicles, pedicellate spikelets with 4 to 8 florets, narrower glumes, and longer, lustrous lemmas.

Variation in mitochondrial DNA and phylogeny of six species of pikas (Ochotona)

Phylogenetic relationships of six species of Ochotona were investigated using mitochondrial DNA (mtDNA) restriction-site analysis. The phylogenetic tree constructed using PAUP was based on 62 phylogenetically informative sites with O. erythrotis designated as an outgroup. Two clades were evident. One contained O. curzoniae, O. huangensis, and O. thibetana. in the second, O. daurica was a sister taxon of O. cansus. The five species appear to come from different maternal lineages. The branching structure of the tree and sequence divergence confirm that huangensis and cansus are distinct species, and that mol-osa is a synonym of O. cansus rather than O. thibetana. Divergence time, estimated from genetic distances, indicates that the ancestors of the two maternal lineages diverged ca. 6.5 x 10(6) years ago. O. curzoniae diverged from O. huangensis, and O. daurica diverged from O. cansus, at about the same time (ca. 3.4 x 10(6) years ago). These data suggest a period of rapid radiation of the genus Ochotona in China, perhaps during the late Pliocene. These calculations correspond roughly to tectonic events and environmental changes in China throughout this period, and appear to be substantiated by the fossil record.

The study of oxygen spillover and back spillover on Pt/TiO2 by a potential dynamic sweep method

Oxygen spillover and back spillover on Pt/TiO2 catalysts have been studied by a potential dynamic sweep method. The characteristics of I-V profiles of Pt/TiO2 electrodes in the three potential sweep regions are different from those of Pt and TiO2 electrodes. The catalytic role of Pt/TiO2 in oxygen spillover and back spillover is identified. It decreases, and the electrochemical oxygen adsorption (or desorption) increases with elevating temperature of hydrogen post-treatment of Pt/TiO2; to a certain extent (hydrogen post-treatment of Pt/TiO2 at 700 degrees C), the control step of oxygen electrode process (anodic oxidation or cathodic reduction) changes from oxygen diffusion to electrochemical oxygen adsorption or desorption, respectively. Increasing the amount of Pt supported on TiO2 enhances the processes of oxygen spillover and back spillover. (C) 1999 Elsevier Science B.V. All rights reserved.