The genus Leptodrepana Shaw was described in 1983, but prior to the current study only one Neotropical species had been described from Mexico and none were named from Costa Rica. In this paper twenty-four new species are described and named from Costa Rica: L. alexisae Dadelahi & Shaw, sp. n., L. atalanta Dadelahi & Shaw, sp. n., L. conda Dadelahi & Shaw, sp. n., L. conleyae Dadelahi & Shaw, sp. n., L. demeter Dadelahi & Shaw, sp. n., L. eckerti Dadelahi & Shaw, sp. n., L. gauldilox Dadelahi & Shaw, sp. n., L. hansoni Dadelahi & Shaw, sp. n., L. kimbrellae Dadelahi & Shaw, sp. n., L. lorenae Dadelahi & Shaw, sp. n., L. munjuanae Dadelahi & Shaw, sp. n., L. ninae Dadelahi & Shaw, sp. n., L. pamelabbas Dadelahi & Shaw, sp. n., L. ronnae Dadelahi & Shaw, sp. n., L. rosanadana Dadelahi & Shaw, sp. n., L. schuttei Dadelahi & Shaw, sp. n., L. scottshawi Dadelahi, sp. n., L. shriekae Dadelahi & Shaw, sp. n., L. sohailae Dadelahi & Shaw, sp. n., L. sorayae Dadelahi & Shaw, sp. n., L. soussanae Dadelahi & Shaw, sp. n., L. stasia Dadelahi & Shaw, sp. n., L. strategeri Dadelahi & Shaw, sp. n., and L. thema Dadelahi & Shaw, sp. n. A key to Costa Rican species of Leptodrepana is provided. The flagellum of all female Leptodrepana described in this work is reduced to only 17 flagellomeres. This character state is also found in two North American species described by Shaw (1983), L. opuntiae Shaw and L. oriens Shaw. It is hypothesized that a female antenna with 17 flagellomeres is a synapomorphy for a species-group comprising all the Costa Rican Leptodrepana species as well as two of the Mexican and North American species, L. opuntiae and L. oriens.
Keywords: Carapace; Malaise traps; Neotropical Region; egg-larval parasitoids.