Abstrakt: |
Abstract: Prey preferences and feeding-related behaviour of a Central European species of Scydmaeninae, Scydmaenus rufus, were studied under laboratory conditions. Results of prey choice experiments involving 22 identified species of mites belonging to 13 families of Oribatida and two families of Mesostigmata (Uropodina) demonstrated that this beetle feeds mostly on oribatid Scheloribatidae (60.38% of prey) and Oppiidae (29.75%) and only occasionally on uropodine Urodinychidae (4.42%) and oribatid Mycobatidae (3.39%); species belonging to Trematuridae (Uropodina), Ceratozetidae and Tectocepheidae (Oribatida) were consumed occasionally. The number of mites consumed per beetle per day was 1.42, and when Oppia nitens was the prey, the entire feeding process took 2.93-5.58 h. Observations revealed that mechanisms for overcoming the prey s defences depended on the body form of the mite. When attacking oribatids, with long and spiny legs, the beetles cut off one or two legs before killing the mite by inserting one mandible into its gnathosomal opening. Flattened and short-legged uropodines were killed in the same way but without cutting off their legs. More legs of the prey were removed during feeding, when the mite was already dead; in Oribatida additional damage included removal of genital plates, whereas the genital structures remained intact in Uropodina. Scydmaenus rufus was able to feed on potentially highly toxic Scheloribatidae, which raises questions about the efficiency of chemical defence in Oribatida. |