Iridoids and volatile pheromones of Tapinoma darioi ants: chemical differences to the closely related species Tapinoma magnum

Abstract

Tapinoma species, and more general dolichoderine ants, are able to produce a variety of volatile compounds they use as chemical defense, alarm, and communication pheromones. Among these, iridoids and volatile ketones are the predominant molecule classes produced by the anal glands of these ants. A recent taxonomic revision of the genus Tapinoma in Europe revealed that the supercolonial species Tapinoma nigerrimum consists of a complex of four cryptic species. Two of them, Tapinoma magnum and the newly described Tapinoma darioi, are closely related species that evolutionary diverged recently. In this work, we determine and characterize the chemical profile of pheromones and volatile compounds of two Tapinoma species. From a chemical point of view, T. darioi and T. magnum show both qualitative and quantitative differences in the pheromones produced, supporting the taxonomic revision of the T. nigerrimum complex. Our data confirm T. darioi and T. magnum as separate species also from a biochemical point of view demonstrating the value of chemotaxonomy as a suitable tool for integrative studies of species differentiation even for closely related taxa.