Monomorium collingwoodi (Hymenoptera: Formicidae), a new ant species of the Monomorium hildebrandti group from Saudi Arabia with a key to the Arabian species

The worker caste of M. collingwoodi, sp. n. is described based on three old specimens of worker caste collected from Al Qatif, Eastern region of Saudi Arabia. This new species belongs to the M. hildebra ndti-group and seems to be closely related to M. jonesi Arnold, from South Africa and M. cryptobium (Santschi) from Zaire. It is diagnosed by the combination of characters: eyes of a single ommatidium, promesonotum in profile with its dorsal outline evenly convex, metanotal groove a sharply impressed U-shaped impression, junction of propodeal dorsum and declivity with a pair of tiny denticles. The queen and male are unknown. The specimens are collected under a date palm tree.

Keywords. Monomorium, hildebrandti-group, Myrmicinae, new species, Alpha taxonomy, key, Palaearctic region, Middle East, Saudi Arabia, date palm.