Differentiation of the ant genus Tapinoma (Hymenoptera: Formicidae) from the Mediterranean Basin by species-specific cuticular hydrocarbon profiles

Correct species identification is a precondition for biological study, yet despite a long history of morphological investigations, the systematic position of many ant species remains unclear. Here, we compared and identified cuticular hydrocarbon profiles of workers of several species of Tapinoma from Algeria, Morocco, Israel, France (mainland and Corsica) and Spain. We used the CHC profiles of workers to identify five Tapinoma species: T. erraticum, T. israele, T. madeirense, T. nigerrimum and T. simrothi. No cryptic species were detected. The species-specific hydrocarbon profiles were found to remain remarkably stable between Morocco and Northern France and between Israel and Algeria. They were not influenced by ecological factors such as vegetation type, soil and climate. In Tapinoma genus, cuticular hydrocarbon profiles were found to have a high diversity in CHC composition. These five identified Tapinoma species shared only three CHC. Combined with morphological analyses, this result confirms the species status of T. madeirense, T. nigerrimum and T. israele. This study also clarifies the geographical distribution of T. simrothi and T. israele and gives some indication of the preponderant frequency of T. nigerrimum.