Genus

About: Genus is a research topic. Over the lifetime, 68921 publications have been published within this topic receiving 590966 citations. The topic is also known as: monospecies genus & genus (zoology).

The genus Hyalomma Koch, 1844: v. re-evaluation of the taxonomic rank of taxa comprising the H. (Euhyalomma) marginatum koch complex of species (Acari: Ixodidae) with redescription of all parasitic stages and notes on biology

Abstract: The systematic morphology of species within the Hyalomma (Euhyalomma) marginatum Koch complex of ticks is illustrated and their relationships within this assemblage are discussed. Traditionally this group comprises the extremely polymorphic species Hyalomma (Euhyalomma) marginatum Koch, 1844 subdivided into four subspecies, namely H. (E.) marginatum marginatum Koch, 1844; H (E.) marginatum rufipes Koch, 1844; H (E.) marginatum isaaci Sharif, 1928 and/H. (E.) marginatum turanicum Pomerantzev, 1946. A fifth member of the association, namely H (E.) glabrum Delpy, 1949, has recently been re-instated as a full species. The taxonomic rank of the first mentioned four ticks is herein raised to species level. Details on the repositories of type specimens, synonyms, descriptions, variability, hosts, geographic distribution, and disease relationships of these four ticks are provided, and all their developmental stages are illustrated.

Radiation of the endemic genus Dendroseris (Asteraceae) on the Juan Fernandez Islands: evidence from sequences of the its regions of nuclear ribosomal DNA

Abstract: Phylogenetic relationships among nine of the 11 species of the endemic genus Dendroseris on the Juan Fernandez Islands were inferred from nucleotide sequences of the internal transcribed spacer regions (ITS) of the 1 8-26S nuclear ribosomal DNA. Sequences were determined for 15 populations of Dendroseris and one population for each of two outgroups from the genera Sonchus and Sventenia. Little length variation was detected in the ITS regions of Dendroseris, with ITS 1 253 or 254 bp long and ITS 2 224 or 225 bp. The sequence data provide strong support for the holophyly of Dendroseris despite the distinct morphological differences among the three subgenera. The molecular data also indicate that subg. Dendroseris and Phoenicoseris are holophyletic, but do not support holophyly of subg. Rea. The ITS sequences did not resolve relationships among subgenera, supporting the hypothesis of rapid adaptive radiation of Dendroseris on the islands. Relative rate tests indicate that rates of nucleotide substitutions in the ITS regions are not significantly different among the different lineages of Dendroseris following adaptive radiation. Comparisons of average pairwise sequence divergence of Dendroseris species in the ITS regions and chloroplast genome indicated that ITS sequences have evolved about 38 times faster than cpDNA in the genus. Rates of ITS sequence divergence of Dendroseris were estimated to be faster than (3.94 ? 0.10) x 1 0-9 per site per year, and likely (6.06 ? 0.15) x 10-9 per site per year. The Juan Fernandez Islands lie 580 km west of mainland Chile at 330 S latitude. The archipelago consists of two major islands-Masatierra and Masafuera-which are approximately 4 million and 1-2 million years old, respectively (Stuessy et al., 1984). The islands, with an unusually high level of endemic flora (60% at the specific level), offer an excellent model system for studying plant phylogeny (Stuessy, Crawford, and Marticorena, 1990). Further, these islands with known ages and rich endemism should serve as a simplified system for studying molecular evolution. The endemic genus Dendroseris D. Don. (Asteraceae: Lactuceae) is the most speciose genus on the Juan Fernandez Islands and consists of 11 species in three subgenera: subg. Dendroseris Skottsb. (D. litoralis Skottsb., D. macrantha [Bertero & Dcne.] Skottsb., D. macrophylla D. Don, and D. marginata [Bertero & Dcne.] Hook. & Am.); subg. Phoenicoseris Skottsb. (D. berteroana [Dcne] Hook. & Am., D. pinnata [Berteroi ex Dcne] Hook. & Am., and D. regia Skottsb.); and subg. Rea (Bertero ex Dcne.) Skottsb. (D. gigantea Johow, D. micrantha [Bertero ex Dcne.] Hook. & Am., D. neriifolia [Dcne.] Hook. & Am., and D. pruinata [Johow] Skottsb.). The three subgenera are quite distinct morphologically, ranging from palmiform and rosette trees to rosette shrubs and sparsely branched trees, which represent the typical habits often encountered in plants on oceanic islands (Carlquist, 1974). Eight of the species are endemic to the older island of Masatierra, and one species in each subgenus (D. macro

A taxonomic study of Australian Aphidoidea (Homoptera).

Abstract: Keys are given for the determination of the families, subfamilies, genera, and the 119 species of aphids known from Australia. The keys are supplemented by 192 figures. The genera of Australian aphids are described in detail and a reference to a recent revision of the genus and to a detailed description of each species is given where possible. A summary of the known host plant range and geographical distribution of each species is given. A few references to recent economic literature are given for those species regarded as pests.

Phylogeny in cryptic weevils: molecules, morphology and new genera of western Palaearctic Cryptorhynchinae (Coleoptera : Curculionidae)

Abstract: A phylogeny is presented for the western Palaearctic representatives of the weevil subfamily Cryptorhynchinae using a combination of phenotypic and genotypic characters. This phylogeny is the first for the extremely species-rich Cryptorhynchinae to use molecular data (mitochondrial CO1 and 16S as well as nuclear ribosomal 28S). The results of this study show the need for molecular tools within this morphologically cryptic group of weevils and provide a scaffold based on which genus assignment can be tested. The present study mostly corroborates the current subdivision into genera (but many of the subgeneric groups are questioned). Three new genera are described: Montanacalles gen. nov. (type species: Kyklioacalles nevadaensis Stuben, 2001), Coloracalles gen. nov. (type species: Acalles humerosus Fairmaire, 1862) and Elliptacalles gen. nov. (type species: Acalles longus Desbrochers, 1892). Relevant external characters and the male genitalia of all discussed taxa are illustrated. Three species are transferred to different genera: Kyklioacalles aubei (Boheman, 1837) (formerly: Acalles), Ruteria major (Solari A. & F., 1907) and Ruteria minosi (Bahr & Bayer, 2005) (both formerly Echinodera).