Eur. J. Entomol. 105: 889–907, 2008 http://www.eje.cz/scripts/viewabstract.php?abstract=1411 ISSN 1210-5759 (print), 1802-8829 (online) Predatory behaviour of some Central European pselaphine beetles (Coleoptera: Staphylinidae: Pselaphinae) with descriptions of relevant morphological features of their heads ANDREA SCHOMANN1, KERSTIN AFFLERBACH2 and OLIVER BETZ3 1Natural History Museum of Denmark/University of Copenhagen, Zoological Museum, Universitetsparken 15, DK-2100 Copenhagen, Denmark; e-mail:
[email protected];
[email protected] 2Eichenstraße 8, 56305 Puderbach, Germany; e-mail:
[email protected] 3Universität Tübingen, Zoologisches Institut, Abteilung für Evolutionsbiologie der Invertebraten, Auf der Morgenstelle 28E, D-72076 Tübingen, Germany; e-mail:
[email protected] Key words. Staphylinidae, Pselaphinae, Brachygluta, Bryaxis, Bythinus, Pselaphus, Rybaxis, Tyrus, predatory behaviour, prey-capture, morphology, head, antenna, mouthparts, maxillary palp, sensillum, sensory organ Abstract. The Pselaphinae is a large subfamily of staphylinid beetles with a characteristic habitus and small body size. Detailed morphological and behavioural studies on these beetles are scarce. In this study, specimens of Bryaxis puncticollis (Denny, 1825), Bryaxis bulbifer (Reichenbach, 1816), Bythinus burrelli (Denny, 1825), Brachygluta fossulata (Reichenbach, 1816), Rybaxis longi- cornis (Leach, 1817), Pselaphus heisei (Herbst, 1792) and Tyrus mucronatus (Panzer, 1803), all collected in Northern Germany, have been examined with regard to their sensory organs (eyes and antennae), mouthparts and method of capturing prey. Scanning electron microscope studies revealed sex-specific differences in the numbers of ommatidia in Bryaxis puncticollis. A multitude of different sensilla on the antennae and great differences in the shape of the mouthparts were observed and peculiarities of the antennae and maxillary palps (e.g., the segment-like appendage) were examined using scanning and transmission electron micros- copy.