Holepyris sylvanidis, ein natürlicher Gegenspieler des Amerikanischen Reismehlkäfers Tribolium confusum; Untersuchungen zur Eindringfähigkeit des Parasitoiden in das Nahrungssubstrat seines Wirtes

Zusammenfassung Das Ameisenwespchen Holepyris sylvanidis (Brèthes, 1913) (Hymenoptera, Bethylidae) ist ein natürlicher Gegenspieler des Amerikanischen Reismehlkäfers Tribolium confusum Jacquelin du Val, 1868 (Coleoptera, Tenebrionidae). T. confusum gilt als bedeutender Schädling in der Nahrungsmittelindustrie sowie in gelagerten Getreideprodukten und tritt in Zentraleuropa vorwiegend in Mühlen und Bäckereien auf. Als Ektoparasitoid der T. confusum-Larven muss H. sylvanidis seine Wirte aufspüren, welche sich in ihren Nahrungssubstraten, wie Mehl und Schrot, in unterschiedlicher Tiefe aufhalten können. Diese Arbeit beschäftigte sich daher mit der Fragestellung, ob der Erfolg von H. sylvanidis bei der Wirtssuche von der Lagetiefe der Wirtslarven im Substrat sowie der Art des Substrates abhängig ist. In Laborversuchen wurde jeweils eine mit 10 T. confusum-Larven bestückte, nicht vollständig geschlossene Petrischale auf dem Boden eines Versuchsglases platziert und mit einer 1, 2, 4 oder 8 cm hohen Schicht feinem oder grobem Weizenvollkornschrot bedeckt (überwiegende Partikelgröße: feiner Schrot < 0,2 mm; grober Schrot 1,4 - 3,0 mm). An der Substratoberfläche wurden jeweils 10 H. sylvanidis-Weibchen und 2 Männchen freigelassen. Je Schrotart und Testtiefe erfolgten 15 Versuchswiederholungen. Die T. confusum-Larven waren nicht in der Lage, die Petrischale zu verlassen, konnten aber von den Wespenweibchen heraustransportiert werden. Das Verschleppen der Wirtslarven ist ein für H. sylvanidis typisches Verhalten, das der eigentlichen Parasitierung vorausgeht. Zwei Wochen nach Versuchsbeginn wurde die Anzahl der verschleppten Käferlarven ermittelt, um den Wirtsfindungserfolg der Wespen bestimmen zu können. In beiden Schrotarten nahm der Anteil der von H. sylvanidis gefundenen Wirtslarven mit zunehmender Tiefe ab. In feinem Schrot fanden die Wespenweibchen ihre Wirtslarven bis zu einer Tiefe von 4 cm, in 8 cm Tiefe platzierte Larven wurden nicht mehr gefunden. Im Gegensatz dazu fanden die Parasitoide in grobem Schrot auch die in 8 cm Tiefe ausgebrachten Wirtslarven. Die Ergebnisse deuten darauf hin, dass eine geringe Partikelgröße des Substrates den Wirtsfindungserfolg von H. sylvanidis verringert. In grobem Schrot sowie in dünnen Schichten eines feinen Substrates erscheint die biologische Bekämpfung von T. confusum mit H. sylvanidis dagegen vielversprechend. Stichwörter: Holepyris sylvanidis, Tribolium confusum, Biologische Bekämpfung, Parasitoid, Eindringfähigkeit, Wirtsfindung   Abstract The bethylid wasp Holepyris sylvanidis (Brèthes, 1913) (Hymenoptera: Bethylidae) is an antagonist of the confused flour beetle Tribolium confusum Jacquelin du Val, 1868 (Coleoptera: Tenebrionidae). T. confusum is a severe pest in the food processing industry and in grain products, in Central Europe primarily in flour mills and bakeries. Females of the larval ectoparasitoid H. sylvanidis face the problem to detect hosts that feed in different depths inside a stored product like flour or grist. The study addressed the question whether successful host finding by H. sylvanidis is dependent on the location of host larvae inside the substrate. Furthermore, it was studied whether the type of substrate affects host finding. In laboratory experiments, 10 T. confusum larvae were placed in a Petri dish accessible to the wasps at a depth of 1, 2, 4 or 8 cm inside either fine or coarse ground wholemeal grist of wheat (main particle size: fine grist < 0.2 mm; coarse grist 1.4 - 3.0 mm). 15 replicates per substrate and depth were performed. 10 female and 2 male parasitoids were released on the surface of the substrate. Host larvae were not able to leave the Petri dish, however, they could be pulled outside the dish by female H. sylvanidis. Within the behavioural sequence of parasitisation, pulling away of host larvae is the behaviour typically preceding oviposition. In order to determine the host finding rate by the parasitoid, the number of missing host larvae was counted two weeks after experiments started. In both types of substrates, host finding decreased with increasing depth. In fine grist, larvae were removed from the Petri dish down to 4 cm depth, however, larvae placed at 8 cm depth were not found anymore. In contrast, in coarse grist host larvae were still parasitised at 8 cm depth. The results suggest that decreasing substrate particle size reduces the host finding capability by H. sylvanidis. Nevertheless, H. sylvanidis may be considered a promising candidate for biological control of T. confusum larvae feeding in coarse ground grist and in thin layers of fine ground grist. Keywords: Holepyris sylvanidis, Tribolium confusum, biological control, parasitoid, penetration ability, host findin

Heisenberg's Uncertainty Relation and Bell Inequalities in High Energy Physics

An effective formalism is developed to handle decaying two-state systems. Herewith, observables of such systems can be described by a single operator in the Heisenberg picture. This allows for using the usual framework in quantum information theory and, hence, to enlighten the quantum feature of such systems compared to non-decaying systems. We apply it to systems in high energy physics, i.e. to oscillating meson-antimeson systems. In particular, we discuss the entropic Heisenberg uncertainty relation for observables measured at different times at accelerator facilities including the effect of CP violation, i.e. the imbalance of matter and antimatter. An operator-form of Bell inequalities for systems in high energy physics is presented, i.e. a Bell-witness operator, which allows for simple analysis of unstable systems.Comment: 17 page

Modeling a bacterial ecosystem through chemotaxis simulation of a single cell

International audienceWe present in this paper an artificial life ecosystem in which bacteria are evolved to perform chemotaxis. In this system, surviving bacteria have to overcome the problems of detecting resources (or sensing the environment), modulating their motion to generate a foraging behavior, and communicating with their kin to produce more sophisticated behaviors. A cell’s chemotactic pathway is modulated by a hybrid approach that uses an algebraic model for the receptor clusters activity, an ordinary differential equation for the adaptation dynamics, and a metabolic model that converts nutrients into biomass. The results show some analysis of the motion obtained from some bacteria and their effects on the evolved population behavior. The evolutionary process improves the bacteria’s ability to react to their environment, enhancing their growth and allowing them to better survive. As future work, we propose to investigate the effect of emergent bacterial communication as new species arise, and to explore the dynamics of colonies

Hadron Production in Heavy Ion Collisions

We review hadron production in heavy ion collisions with emphasis on pion and kaon production at energies below 2 AGeV and on partonic collectivity at RHIC energies.Comment: 31 pages, 26 figures, accepted for publication in Landolt-Boernstein Volume 1-23

Four-Body Bound State Calculations in Three-Dimensional Approach

The four-body bound state with two-body interactions is formulated in Three-Dimensional approach, a recently developed momentum space representation which greatly simplifies the numerical calculations of few-body systems without performing the partial wave decomposition. The obtained three-dimensional Faddeev-Yakubovsky integral equations are solved with two-body potentials. Results for four-body binding energies are in good agreement with achievements of the other methods.Comment: 29 pages, 2 eps figures, 8 tables, REVTeX

Neurological presentation of Whipple's disease after long-term antibiotic treatment: a case report

<p>Abstract</p> <p>Introduction</p> <p>Whipple's disease is a rare systemic infectious disorder caused by <it>Tropheryma whipplei</it>.</p> <p>Case presentation</p> <p>We report a 68-year-old male with Whipple's disease of the central nervous system following long-term antibiotic therapy and many years after the initial clinical onset.</p> <p>Conclusion</p> <p>The combination of trimethoprim and sulphamethoxazole does not prevent or cure involvement of the central nervous system in all patients with Whipple's disease. If relapse of the central nervous system occurs treatment with meropenem might be a useful alternative.</p

Heavy Quark Photoproduction in Ultra-peripheral Heavy Ion Collisions

Heavy quarks are copiously produced in ultra-peripheral heavy ion collisions. In the strong electromagnetic fields, c c-bar and b b-bar are produced by photonuclear and two-photon interactions; hadroproduction can occur in grazing interactions. We present the total cross sections, quark transverse momentum and rapidity distributions, as well as the Q Q-bar invariant mass spectra from the three production channels. We consider AA and pA collisions at the Relativistic Heavy Ion Collider and Large Hadron Collider. We discuss techniques for separating the three processes and describe how the AA to pA production ratios might be measured accurately enough to study nuclear shadowing.Comment: Minor changes to satisfy referees and typo fixes; 52 pages including 17 figure