The plam-feeding planthopper genus Ommatissus (Homoptera: Fulgoroidea: Tropiduchidae)

Abstract The tribe Trypetimorphini, the genus Ommatissus , and its two subgenera and eleven species are redescribed or described as new. Evidence for the monophyly of both the genus and of the tribe to which it belongs is examined; it is concluded that while the genus is monophyletic, the monophyly of the tribe is in doubt. Keys for the separation of the three genera of the tribe and for all of the known species of Ommatissus are presented. A new subgenus of Ommatissus is described: O.(Opatissus) , with the type-species O.vietnamicus . Four new species are described: Ommatissus magribus from Morocco, O.kamerunus from Cameroon, O.natalensis from South Africa and O.vietnamicus from Vietnam. The 'Dubas bug', Ommatissus lybicus Bergevin, formerly regarded as a variety of O.binotatus Fieber, is raised to full species status. Trichoduchus is synonymized with Trypetimorpha resulting in the new combinations Trypetimorpha biermani Dammerman, T.china Wu and T.japonicus Ishihara. Trichoduchus japonicus Fennah is synonymized with Trypetimorpha japonicus Ishihara.     

A molecular phylogeny of the cosmopolitan hyperdiverse genus Hydraena Kugelann (Coleoptera,Hydraenidae)

With almost 900 described species, Hydraena Kugelann (Hydraenidae) is one of the largest genera among Coleoptera. The subgeneric classification of Hydraena has been controversial, with 11 subgeneric names having so far been attributed to it. Some of these, Haenydra Rey and Spanglerina Perkins, have been treated as valid genera, as subgenera or as species groups. The most recent complete treatment of the genus, based on a cladistic analysis of morphological characters, recognized two major lineages, and only these were classified as subgenera: Hydraenopsis (mainly Gondwanan distribution), and Hydraena s.str. (mainly Laurasian). Here, we reconstruct the phylogeny of Hydraena using 212 species plus several outgroups and approximately 4 kb of sequence data from two nuclear (SSU and LSU) and four mitochondrial genes (cox1, rrnL, trnL and nad1). Data were aligned with two different strategies of multiple alignment (implemented in mafft and prank ), and the phylogenies reconstructed using maximum likelihood and Bayesian methods. We estimated approximate ages of the main nodes using a relaxed molecular clock with Bayesian methods, and an a priori evolutionary rate of 0.01 substitutions/site/million years (Ma) plus a calibration point based on a biogeographical split. We found strong support for the monophyly of Hydraena and many of the clades recognized with morphological data. The following clades are considered as subgenera: Phothydraena Kuwert, Spanglerina Perkins, Holcohydraena Kuwert, Hydraenopsis Janssens and Hydraena s.str. The placement of three species groups, two Neotropical (H. multispina group, H. paeminosa group) and one South African/Madagascan (H. monikae group), is uncertain, and they are considered incertae sedis within Hydraena. The origin of the genus was estimated to be in the Lower Eocene, with many species complexes diversifying in the Pleistocene. Dispersal events seem to have played a key role in order to determine the current distribution of the species groups in the southern hemisphere (mainly in Hydraenopsis).     

The Role of Soil Arthropods in Community Energetics

Though the primary development of principles of energetics waspioneered in aquatic studies, considerable information has accruedfrom more recent investigations of terrestrial species. Studiesof soil organisms—particularly arthropods—have givenus some understanding of the applicability of principles ofenergetics to terrestrial communities. Data from soil communitieshave yielded an annual energy budget for oribatid mites, ecologicalefficiencies for two trophic levels, and a series of herbivore:carnivoreratios for a number of communities. Energy-flow analyses ofthe problems of species abundance in community organization,the relationship of population production and maintenance, andthe energy relationships of the soil to above-ground communitieshave also been attempted. As data accumulate, however, the inadequacyof the Lindeman model becomes apparent, and there are prospectsfor change in this conceptual scheme.     

Dynamics in a butterfly–plant–ant system: influence of habitat characteristics on turnover rates of the endangered lycaenid Maculinea alcon

Abstract.  1.  Maculinea alcon , a myrmecophilic, stenotopic lycaenid butterfly is restricted to wet heathlands, bogs, and nutrient-poor hay meadows. Due to intensification of agriculture and decrease of extensively grazed meadows, many suitable habitats have disappeared and the remaining ones are highly fragmented and deteriorated.
2. Historical distribution data and a comparison with the present occupation of patches show the decline of this critically endangered butterfly in north-west Germany. Most of the populations in north-west Germany are small and often geographically isolated.
3. In summer 2002, two-thirds of 77 investigated potential patches were unoccupied as a result of unsuitable habitat structure and habitat fragmentation.
4. Several habitat parameters were highly significantly correlated with the presence of M. alcon , in particular the distribution pattern of the host plant Gentiana pneumonanthe. Furthermore, butterflies were absent from many patches with an incidence probability below 50% with respect to patch size and isolation.
5. In the nature reserve Lüneburger Heide, part of the study area, M. alcon populations have been observed since 1995. Typical turnover of local populations could be detected during these years. Extinctions and re-colonisations have stabilised the presence of this species in a metapopulation in this nature reserve.
6. These data show the importance of different factors on different spatial levels influencing the presence of this endangered butterfly.     

Perissothallus, a new genus for Late Pennsylvanian–Early Permian noncalcareous algae conventionally assigned to Schizopteris (aphleboid foliage)

The morphogenus Schizopteris was established in the early 19th century for late Palaeozoic aphleboid foliage of uncertain affinities, and numerous specimens have subsequently been assigned to this taxon. Some of these fossils do not represent foliage, but rather noncalcareous algae. Although this inconsistency has been noted, an attempt to exclude the algae from Schizopteris has not yet been undertaken. Here we propose the new genus Perissothallus to accommodate those fossils conventionally assigned to Schizopteris that represent algae. The name P. versiformis is introduced for the type species from the Upper Pennsylvanian of Kansas (USA). Specimens from the Lower Permian of Germany are interpreted as a second species of Perissothallus , and the name P. densus is proposed. Perissothallus consists of erect cylindrical branches that radiate from a small holdfast and dichotomize repeatedly. Vegetative reproduction occurs in the form of daughter thalli produced on prostrate branches. Similarities in basic structure exist between Perissothallus and members of the extant algal genera Codium (Chlorophyta), Dictyota (Phaeophyta), and Scinaia (Rhodophyta).  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 477–488.     

Phylogeny of Psephenidae (Coleoptera: Byrrhoidea) based on larval, pupal and adult characters

Abstract.  We conducted the first comprehensive phylogenetic analysis of Psephenidae, based on 143 morphological characters of adults, larvae and pupae and coded for 34 taxa, representing three outgroups and 31 psephenid genera, including four undescribed ones. A strict consensus tree calculated (439 steps, consistency index = 0.45, retention index = 0.75) from the two most-parsimonious cladograms indicated that the monophyly of the family and subfamilies is supported, with the exception of Eubriinae, which is paraphyletic when including Afroeubria . Here a new subfamily, Afroeubriinae ( subfam.n. ), is formally established for Afroeubria . The analysis also indicated that the 'streamlined' larva is a derived adaptive radiation. Here, suprageneric taxonomy and the evolution of some significant characters are discussed. Keys are provided to the subfamilies and genera of Psephenidae considering larvae, adults and pupae.     

Kinetic changes with temperature of phosphoenolpyruvate carboxylase from a CAM plant

Abstract. Purified and crude phosphoenolpyruvate carboxylase from the CAM plant Kalanchoë daigremontiana Hamet et Perrier ( Bryophyllum diagremontianum ) was assayed at temperatures between 10 and 45° C. The optimum temperature of the enzyme activity changed with substrate availability and effector concentration in the assay. l -malate inhibited the enzyme activity and lowered the optimum temperature. Glucose-6-phosphate raised the optimum temperature to 43°C. K _m values for phosphoenolpyruvate increased with assay temperature from 0.12 mol m^-3 at 15° C to 0.36 mol^m−3 at 35° C. Inhibition by malate increased with temperature and acidity of the assay. In the crude enzyme 50% of control activity was inhibited by 1.65 mol m^-3 malate at 15° C and by 0.5 mol m^-3 at 35° C (at pH 7.0). With purification malate sensitivity was lost ( K _i values for malate at least 10 times higher). The shift in optimum temperatures for PEP-carboxylase activity thus results from changes in the kinetic parameters with temperature and allosteric effectors. The often low optimum temperatures for CO₂ fixation observed in nature may thus be the result of substrate and effector concentrations in the cytoplasm and the antagonistic effect of temperature on substrate affinity and effector efficiency on phosphoenolpyruvate carboxylase.     

Structure and Evolution of a Bifunctional Enzyme of the Tryptophan Operon

Multifunctional enzymes composed of a single polypeptide chain could conceivably have arisen through the fusion of contiguous genes coding for distinct proteins. An example of this may be tryptophan synthetase, which is a single bifunctional protein in fungi but a complex of two distinct polypeptide chains in bacteria such as Salmonella typhimurium.     

AFM IMAGING AND ELASTICITY MEASUREMENTS ON LIVING RAT LIVER MACROPHAGES

The authors investigated the morphology and the elastic properties of living cultured rat liver macrophages (Kupffer cells) with an atomic force microscope (AFM). Continuous imaging and elasticity mapping of individual cells in physiological buffer was carried out for several hours without damaging the cells as judged by their persistent undisturbed morphology. Dynamic events such as protrusive activity were observed in time course. The importance of the cytoskeleton for the mechanical properties of the cell has been investigated by measuring the cell's elasticity as a function of position. Chemical disassembly of the actin network by applying 10μg/ml cytochalasin B decreased the cell's average elastic modulus seven-fold within less than 40 minutes. Treating the cells with 0.1μg/ml latrunculin A resulted in a two-fold decrease in the elastic modulus merely in the perinuclear region after 40 minutes, whereas other parts of the cell were not affected.