Assembling and alerting scents produced by the bedbugCimex lectularius L.

Zusammenfassung Es wird gezeigt, dass die Aggregation der Bettwanzen (Cimex lectularius) durch einen von beiden Geschlechtern abgegebenen Versammlungsduft eingeleitet wird. Letzterer ist in Methylalkohol, aber nicht in Diäthyläther löslich, verdampft bei 32°C und lockt unbegattete sowie begattete Wanzen beider Geschlechter an. Die Lockreaktion ist von der Duftmenge abhängig und bleibt bei antennenlosen Wanzen aus. Die Stinkdrüsen gereizter, respektive verletzter Bettwanzen sondern Hex-2-en-1-al und Oct-2-en-1-al als Alarmduft ab, der die Zerstreuung der Wanzengruppen hervorruft.     

A star in a 15.2-year orbit around the supermassive black hole at the centre of the Milky Way

Many galaxies are thought to have supermassive black holes at their centres-more than a million times the mass of the Sun. Measurements of stellar velocities and the discovery of variable X-ray emission have provided strong evidence in favour of such a black hole at the centre of the Milky Way, but have hitherto been unable to rule out conclusively the presence of alternative concentrations of mass. Here we report ten years of high-resolution astrometric imaging that allows us to trace two-thirds of the orbit of the star currently closest to the compact radio source (and massive black-hole candidate) Sagittarius A*. The observations, which include both pericentre and apocentre passages, show that the star is on a bound, highly elliptical keplerian orbit around Sgr A*, with an orbital period of 15.2 years and a pericentre distance of only 17 light hours. The orbit with the best fit to the observations requires a central point mass of (3.7 +/- 1.5) x 10(6) solar masses (M(*)). The data no longer allow for a central mass composed of a dense cluster of dark stellar objects or a ball of massive, degenerate fermions.     

The coagulation of insect hemolymph

In contrast to both vertebrates and non-insect arthropods, little is known about the coagulation of hemolymph (hemostasis) in insects. We discuss the integration of the hemostatic response with other branches of the insect immune system. We also describe the present stage in the characterization of both soluble and cellular factors that contribute to hemostasis in insects. The factors of the well-characterized clotting cascades of vertebrates, primitive chelicerates and crustaceans are used to assess the implications of sequencing the whole Drosophila genome for searching candidate genes involved in hemostasis. Some striking similarities between blood clotting in vertebrates and the reaction of insect cells involved in hemolymph coagulation have implications for a phylogenetic comparison of hemostasis between divergent animal classes.