ABDOMINAL GLAND SECRETION OF BLEDIUS ROVE BEETLES AS AN EFFECTIVE DEFENSE AGAINST PREDATORS

The biological function of the abdominal gland of the rove beetle genu s Bledius (Coleoptera: Staphylinidae: Oxytelinae) was examined using b ehavioural criteria. The attractant effect of the abdominal secretion on the Bledius predators Dyschirius obscurus and D. thoracicus (Carabi dae), described in the literature, was identified as artificial. In ch oice experiments the secretion showed repellent effects on natural pre dators of Bledius furcatus, B. spectabilis and B. arenarius. In predat or-prey encounters with Cataglyphis bicolor (Formicidae) and Labidura riparia (Dermaptera) the gland secretion of B. furcatus induced cleani ng behaviour. When attacked by C. bicolor the chance of survival for B . furcatus was increased by the presence of the abdominal gland secret ion. This clearly shows that the abdominal gland of the genus Bledius is used for defensive purposes.