A new species of aleocharine rove beetle, Thamiaraea paralira, from New York and Mississippi, is described and illustrated. It is distinguished from T. lira Hoebeke, to which it is very similar, by its smaller body size and by the distinct dentation of the apical margin of the male tergum VIII. New distributional data for T. americana Bernhauer (Kansas) and T. lira (Kansas, Mississippi, North Carolina, Wisconsin, and Ontario) are provided. Specimens of both species have been taken from fermenting sapflows (slime fluxes), one of the principal habitats of species of the genus.