Two additions to the Iberian myrmecofauna: Crematogaster inermis Mayr, 1862, a newly established, tree-nesting species, and Trichomyrmex mayri (Forel, 1902), an emerging exotic species temporarily nesting in Spain (Hymenoptera, Formicidae)

Exotic ants are a growing component of urban and disturbed habitats worldwide. Sampling in two Iberian Mediterranean localities revealed several exotic species. The tree-nesting, black acrobat ant Crematogaster inermis Mayr, 1862, has been detected nesting outdoors on a Robinia pseudoacacia tree in a public garden in Valencia (Spain) and represents a new addition to the continental European fauna. Collection details, a morphological description, biometry, and the remarkable presence of short spines in smaller specimens are also given for this species. A case of an ephemeral establishment of several exotic ant species in a palm grove is also discussed. This case includes C. inermis and Trichomyrmex mayri, also a novelty for the Iberian Peninsula.