Electrophysiological and behavioural analyses on prey searching in a myrmecophagous carabid beetle Siagona europaea Dejean 1826 (Coleoptera, Carabidae)

n the present study, electrophysiological and behavioural tests were performed on Siagona europaea Dejean 1826 adults to investigate the importance of chemical cues in ant location. Olfactory responses of labial palp to terpenoids (citral, limonene and geraniol), carboxylic acids (acetic and formic acids), aliphatic ketones (heptanone) and aldehydes (hexanal) were tested by means of an electropalpogram (EPG) bioassay. Our electrophysiological results showed that only acetic and formic acids evoked EPG responses. Y-shape olfactometer bioassays showed that adults were attracted by acetic and formic acids. The role of these chemicals on prey detection is discussed.