Clarifying Irish records for the rare ants Stenamma westwoodii Westwood and S . debile (Foerster) (Hymenoptera: Formicidae)

The genus Stenamma Westwood contains 84 inconspicuous species of cryptic habits. Two species, S . westwoodii Westwood and S . debile (Foerster) are historically recorded from Ireland. Both species occur in Britain but most historical records of S . westwoodii there have been reassigned to S . debile . Confusion has persisted as to the identities of Irish Stenamma records, and both species are included in several recent publications covering the Irish ant fauna. This study re-evaluates all published Stenamma records from Ireland and corrects nomenclatural and distributional errors in prior literature. Examination of voucher specimens in the National Museum of Ireland (NMI) confirmed that only S . debile occurs here, and all historical S . westwoodii records can be reassigned to S . debile . While the species is still rare in Ireland, it is certainly more widely distributed than previously known, showing a southerly bias similar to the species??? British distribution. As with British and European populations, Irish records come from native woodland habitats, but also from coniferous forests, open scrub, limestone pavement, urban greens and roadside ditches. Phenological data indicate activity from January to October, with a peak in September that probably aligns with autumn nuptial flights.