Costatrichia Mosely, 1937 (Leucotrichiini) is for the first time recorded from Brazil. Two new species are described: Costatrichia nelsonferreirai sp. nov. and C. fluminensis sp. nov. from states of Pará and Rio de Janeiro, respectively. Costatrichia nelsonferreirai sp. nov. is similar to C. bipartita Flint, 1970, but can be distinguished from the latter by a pair of ventrolateral bifurcate processes on the posterior margin of male segment VIII. Costatrichia fluminensis sp. nov. is similar to C. simplex Flint, 1970, but the former can be easily distinguished from the latter by a pair of slender lateral processes on the posterior margin of male segment IX and by a spatulate apical process on phallus.
Amazon Forest; Atlantic Forest; Costatrichia nelsonferreirai sp. nov.; Costatrichia fluminensis sp. nov.; Leucotrichiini
