Peter C. Zwick

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Global Positioning System vectors and surface tilt rates are inverted simultaneously for the rotation of western Oregon and plate locking on the southern Cascadia subduction thrust fault. Plate locking appears to be largely offshore, consistent with earlier studies, and is sufficient to allow occasional great earthquakes inferred from geology. Clockwise(More)
Biodiversity is undisturbed rhithral streams in central Europe is high, with about 1000 resident metazoan species; over 600 insect species occur in the Fulda river (Germany). Longitudinal downstream shift of dominance from rheobiontic to rheophilous and finally to ubiquituos rheoxenic taxa in the potamal is described. Present downstream importance of(More)
Today’s knowledge of worldwide species diversity of 19 families of aquatic Diptera in Continental Waters is presented. Nevertheless, we have to face for certain in most groups a restricted knowledge about distribution, ecology and systematic, particularly in the tropical environments. At the same time we realize a dramatically decline or even lack of(More)
Upstream oviposition flights of several Plecoptera species of the genera Leuctra, Nemoura, Isoperla and Siphonoperla along the Breitenbach, Hesse, Germany are inferred from 1. oviposition occuring upstream from emergence areas; 2. size differences and size-shifts between emerging and egg-laying females; 3. concentration of oviposition in upstream sections(More)
Nemurella pictetii Klapálek, 1900 (Plecoptera: Nemouridae) has bi-or trimodal emergence patterns in Central Europe. The emergence threshold temperature is about 8°C. Egg development is direct. The slopes of regressions describing its temperature dependence do not differ significantly between English, Norwegian and German populations, but the intercepts(More)
Aspects of the nymphal/adult developmental change were investigated in biometric studies of several species of Plecoptera: Nemouridae near Schlitz, Hesse, Germany. Preliminary information on the mayfly, Baetis vernus Curtis, is also provided. Nemourid nymphs pass through 3 wing bearing stages before reaching adulthood. Instars can be identified by their(More)
Considerable variation of life cycle duration in given insect species has been frequently recorded. Splitting of populations into cohorts with different life cycle lengths may occur, sometimes even between siblings from the same batch. Larval populations of the stonefly Nemurella pictetii in central Europe regularly split into a very fast developing and a(More)
New monotypic genera proposed are: Cygnocyphon ibex n. gen., n. sp., Eximiocyphon excisus n. gen., n. sp., and Paracyphon avicularis n. gen., n. sp. Also proposed are the new genera Leptocyphon n. gen., with L. furcalonga, n. sp. and L. quadricornutus, n. sp., Tectocyphon n. gen., with T. microphallus n. sp., T. hirsutus n. sp., and T. victoriae n. sp. The(More)
The new genus Nothocyphon (type species: Helodes (Cyphon ?) lindensis Blackburn, 1892) is proposed for small Contacyphon-like Australian beetles. The included species exhibit a generalized body structure, lacking the derived character expressions of related genera. Male tergite 9 is very weakly developed, membranous and bare. This is derived but as a(More)
The related new genera Austrocyphon and Tasmanocyphon are erected for 42 small Australian marsh beetles resembling members of the genus Cyphon Paykull in habitus. They are distinguished from Cyphon. Only males are known of most species but for two of them larvae and pupae are also available. Austrocyphon species occur in all Australian Federal States, and(More)