Two new species of Szelenyiopria Fabritius (Hymenoptera, Diapriidae), larval koinobiont endoparasitoids of the leaf-cutter ant Acromyrmex coronatus (Fabricius) (Hymenoptera, Formicidae), from Panama.

Leaf-cutter ant nests attract a wide variety of guests and parasites due to considerable food resources, substrate and shelter available within nests. Limited information is known about their taxonomy, bionomics, and natural history, including interactions with the ants, and degree of host specificity of these symbionts. Here we describe two new species of Szelenyiopria Fabritius, 1974 (Diapriidae, Diapriinae, Diapriini) wasps which are koinobiont endoparasitoids of the larvae of a leaf-cutter ant, Acromyrmex coronatus (Fabricius, 1804) (Myrmicinae, Attini) in Chiriquí, Panama. For both new Szelenyiopria species, S. fortunensis Araúz & Fernández-Marín, sp. nov. and S. chiriquiensis Araúz & Fernández-Marín, sp. nov., we provide information on parasite-host interactions. The most abundant and frequent parasitoid type was solitary, while gregarious parasitoidism, where two or more wasps emerged from a single ant larva, was associated with certain times of the year. We provide an updated key to females of all species of Szelenyiopria, their geographic distribution, and host-parasite interactions. Szelenyiopria previously had been identified as parasitoids of several ant genera including some Acromyrmex species, but our data indicate that some species of Szelenyiopria may be specialized on A. coronatus ants. Rates of parasitism suggest that the wasps have a negative effect on colonies and populations of the ants.