The Ochodaeidae of Argentina (Coleoptera, Scarabaeoidea)

The Ochodaeidae (Coleoptera: Scarabaeoidea) of Argentina are revised. Previously, two species of Ochodaeinae were known from the country, both in the genus Parochodaeus Nikolajev: P. campsognathus (Arrow) and P. cornutus (Ohaus). An additional 7 species of Parochodaeus from Argentina are described here as new. In addition, Gauchodaeus patagonicus, new genus and new species in the subfamily Chaetocanthinae, is described. "is is the #rst record of the subfamily Chaetocanthinae in South America. Redescriptions, diagnoses, and maps are provided for each species. We also provide a key to genera and a key to species of Parochodaeus of Argentina. With this work, the number of ochodaeid species known from Argentina is increased from 2 to 10.Fil: Paulsen, M. J.. University of Nebraska; Estados UnidosFil: Ocampo, Federico Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentin

Beitrag des ökologischen Landbaus zum Meeresumweltschutz

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Hyperuniformity with no fine tuning in sheared sedimenting suspensions

Particle suspensions, present in many natural and industrial settings, typically contain aggregates or other microstructures that can complicate macroscopic flow behaviors and damage processing equipment. Recent work found that applying uniform periodic shear near a critical transition can reduce fluctuations in the particle concentration across all length scales, leading to a hyperuniform state. However, this strategy for homogenization requires fine tuning of the strain amplitude. Here we show that in a model of sedimenting particles under periodic shear, there is a well-defined regime at low sedimentation speed where hyperuniform scaling automatically occurs. Our simulations and theoretical arguments show that the homogenization extends up to a finite lengthscale that diverges as the sedimentation speed approaches zero.Comment: 11 pages, 6 figure

Mixed cropping systems for control of weeds and pests in organic oilseed crops

Agricultural advantages of mixed cropping are gained from biological effects like light competition offering weed-suppressing capacities, or by diversification of plant covers to break development cycles of pests. These effects were measured in a two-year project on mixed cropping with organic oilseed crops. It was found that weeds can be efficiently suppressed in organic linseed (Linum usitatissivum) grown in combination with wheat (Triticum aestivum) or false flax (Camelina sativa). Linseed growth was, however, impaired. In organic pea production (Pisum sativum) also, growing the crop as a mixture with false flax led to a significant decrease of weed population. Either culture showed a balanced plant development. In winter rape (Brassica napus) there were suggestions that infestation by insect pests can be directly reduced in mixtures with cereals or legumes and that parasitoids of insect pests are supported

The inexorable resistance of inertia determines the initial regime of drop coalescence

Drop coalescence is central to diverse processes involving dispersions of drops in industrial, engineering and scientific realms. During coalescence, two drops first touch and then merge as the liquid neck connecting them grows from initially microscopic scales to a size comparable to the drop diameters. The curvature of the interface is infinite at the point where the drops first make contact, and the flows that ensue as the two drops coalesce are intimately coupled to this singularity in the dynamics. Conventionally, this process has been thought to have just two dynamical regimes: a viscous and an inertial regime with a crossover region between them. We use experiments and simulations to reveal that a third regime, one that describes the initial dynamics of coalescence for all drop viscosities, has been missed. An argument based on force balance allows the construction of a new coalescence phase diagram

A remarkable new species of \u3ci\u3eNothochodaeus\u3c/i\u3e Nikolajev from Sumatra (Coleoptera: Scarabaeoidea: Ochodaeidae)

Nothochodaeus marsupialis Paulsen, new species (Coleoptera: Ochodaeidae), is described from Aceh Province, Indonesia, on the island of Sumatra. The species possesses deep abdominal cavities behind a shield-like central process, as well as rows of conical tubercles laterally on the second and third ventrites. These structures have not been found in any other members of the genus or family

Correction of the misidentifi cations and confusion surrounding \u3ci\u3eOchodaeus grandiceps\u3c/i\u3e Fairmaire, 1897 (Coleoptera: Ochodaeidae), and the description of a new species of ochodaeid from Cuba

Multiple sources of confusion surround the identity of Ochodaeus grandiceps Fairmaire, 1897, from Sichuan, China (Coleoptera: Ochodaeidae). Herein the type specimen is illustrated to solve these taxonomic issues. Examination of the holotype indicates that the species must be transferred to the genus Nothochodaeus Nikolajev, 2005, resulting in a new combination. The genus Mimochodaeus Nikolajev, 2009, based on a misidentifi cation of O. grandiceps as its purported type species, is discussed. Finally, Cuban specimens had been treated erroneously as belonging to O. grandiceps, and so the species had remained undescribed. A new species, Parochodaeus perdidus, is described to accommodate them

A new species of stag beetle (Coleoptera: Lucanidae) from California

A new species of Platyceroides Benesh, P. potax, n. sp., is described from the northern Sierra Nevada Mountains in California, USA, and compared to the most similar species, Platyceroides opacus (Fall)