A new species from the Philippines closely related to the emerald ash borer, Agrilus planipennis Fairmaire, 1888 (Coleoptera: Buprestidae) is described: Agrilus rubensteini Chamorro and Jendek, new species. This is the first species in the A. cyaneoniger species-group recorded for the Philippines. Agrilus rubensteini resembles A. pseudolubopetri Jendek and Chamorro specifically by the elongate and narrow body shape, the narrow marginal and submarginal pronotal interspace not reaching the anterior pronotal margin, absent prehumerus and arcuate elytral apices, however, it can be easily distinguished from any other species in the group by the presence of golden tomentum in lateral pronotal impressions and laterally on ventrites 3 and 4.