2 research outputs found
Chemical secretion and morpho-histology of the pygidial glands in two Palaearctic predatory ground beetle species: Carabus (Tomocarabus) convexus and C. (Procrustes) coriaceus (Coleoptera: Carabidae)
Although all ground beetles have pygidial glands homologous in structure and function, there are many differences among species, often significant, in terms of chemical composition of the secretion and morphology of the gland components. In this paper, two predatory ground beetle species of the genus Carabus, namely C. (Tomocarabus) convexus and C. (Procrustes) coriaceus, were subjected to chemical, morphological and histological study of their pygidial glands and the glands' secretions. Altogether, three carboxylic acids were isolated, and the pygidial gland reservoir and other glandular parts are morphologically described in the study. We also tested whether there exist differences in chemical content of the secretion obtained by upsetting the beetles in a traditional way and that obtained directly from intact reservoirs. Detailed data on morphology of the pygidial glands of both species are presented, as well as updated information about the chemical components of the glandular secretions. Apart from tiglic and methacrylic acids, which are typical for Carabus pygidial secretions, we also found benzoic acid as a minor component of the secretion in both species. In addition, a chemotaxonomic overview of Carabus taxa is given in the paper
Molecular Diversity of Compounds from Pygidial Gland Secretions of Cave-Dwelling Ground Beetles: The First Evidence
Three adult cave-dwelling ground beetle species were induced to
discharge secretions of their pygidial glands into vials.
Dichloromethane extraction was used to obtain the secretions. In total,
42 compounds were identified by GC/MS analysis. Pheggomisetes ninae
contained 32 glandular compounds, Laemostenus (Pristonychus) punctatus
13, whereas Duvalius (Paraduvalius) milutini had nine compounds.
Caproic, oleic, palmitic, and stearic acids were present in the samples
of all analyzed species. Undecane was predominant in the extract of L.
punctatus. Palmitic acid was the major component in the secretion of D.
milutini. Finally, the most abundant compounds in P. ninae secretion
were heptacosene and nonacosadienes. Herein, we present the first data
on the identification of pygidial gland secretion components in both
troglophilous and troglobite cave-dwelling ground beetles. Some
compounds are reported for the first time in the secretions of ground
beetles and other higher or lower taxa. The adaptation to underground
life has not led to a reduction or changes in the chemical defense
mechanism in the analyzed troglophilous and troglobitic Platyninae and
Trechinae taxa.Serbian Ministry of Education, Science, and Technological Development
{[}173038, 172053, 173027