Pygidial gland secretions of Carabus Linnaeus, 1758 (Coleoptera: Carabidae): chemicals released by three species

Abstract

It is a commonly known fact that all ground beetles possess abdominal pygidial glands with relatively similar gross structure and function among species. Still, morphology of the glands and composition of their secretions have not been studied in most ground beetle species. These exocrine glands and their products are mainly associated with defence in natural environments. In this paper, we studied three predatory ground beetle species of the genus Carabus Linnaeus, 1758, namely C. (Archicarabus) montivagus Palliardi, 1825, C. (Megodontus) caelatus Fabricius, 1801, and C. (M.) violaceus Linnaeus, 1758, to identify chemical components of their pygidial gland secretions. Altogether, 10 carboxylic acids were isolated from the analysed secretions [two from the secretion of C. (A.) montivagus, 10 from that of C. (M.) caelatus, and nine from that of C. (M.) violaceus]. The finding of 2-hexenoic acid in the secretion of C. (M.) caelatus is the first finding of it within the entire subfamily Carabinae. In addition, we also analysed the morphology of glands of the species C. (M.) violaceus.