Two new Costa Rican species of the braconid parasitoid wasp subfamily Cardiochilinae, Heteropteron kidonoi Dabek & Whitfield and Heteropteron hasegawai Dabek & Whitfield, are described and illustrated from dry forest in the Area de Conservacion Guanacastae, along with data on rearing from their hosts. Heteropteron kidonoi is a solitary endoparasitoid of Stenoma cathosiota (Lepidoptera: Depressariidae) on Roupala montana (Proteaceae), while H. hasegawai is a solitary endoparasitoid of Carthara abrupta (Lepidoptera: Pyralidae) on the same host plant, but typically at slightly higher elevation localities. Diagnostic characters are provided to distinguish these two new species from each other, and also from the three previously decsribed species of Heteropteron. Heteropteron kidonoi and H. hasegawai are the first species of Heteropteron to have any host data, and also are the first to be reported in Costa Rica.