Geographical variation in Micrathyria mengeri Ris, with a description of M. mengeri watsoni ssp. nov. (Anisoptera: Libellulidae)

M. m. watsoni ssp.n. (holotype <J: Costa Rica, Heredia prov., 2.5 km S Puerto Viejo; FSCA, Gainesville) ranges from Belize to Colombia and W Venezuela, while M. m. mengeri ranges from Trinidad to E Venezuela and Brazil. Male of the new ssp. has cerci each with a row of ventral denticles, but no other ventral or medial projections, while in the nominate ssp. there are ventral and medial projections on each of the cerci. The females are very similar, but the occiput of watsoni is more convex posteriorly. The relationship between the 2 taxa and their biology are discussed.