RESUMO
The genus Ceraeochrysa Adams is widely distributed in the New World, from southeastern Canada to Argentina, with 15 out of 61 previously known species recorded in Mexico. In this paper, Ceraeochrysa tacanensis sp. nov. is described and illustrated from Volcán Tacaná, Chiapas, and an identification key to Ceraeochrysa species present in Mexico is provided. The new species is similar to others with swollen and darkened posterior branches of the cubital vein, and it can be separated from these other species by an elongate gonapsis extending from the base of the gonosaccus; the gonapsis is slightly upturned, terminating in a rounded apex with dorsal microteeth. Females of the new species have non-distinctive genitalia morphology. However, they can be associated with males of the species by body color pattern, synchrony, and sympatry.