Key to Costa Rican species of the Leurus caeruliventris complex The following key is based solely on morphology, but in a few cases (couplets 7 and 9) we were unable to find morphological differences. Cryptic species therefore fall out together and the only apparent way they can be separated is via DNA. 1. Metasoma black, without any metallic reflection............................................................ 2 – Metasoma with at least some metallic blue reflection (Fig. 1).................................................. 4 2. Tegula pale anteriorly, orangish posteriorly (Fig. 5). [Scape entirely yellowish.]................................................................................................. L. marjorietownesae Zuñiga & Valerio sp. nov. – Tegula pale anteriorly, dark posteriorly (Fig. 10)............................................................ 3 3. Mid femur black; dorsal surface of scape mostly dark (Fig. 10)....... L. pammitchellae Zuñiga & Valerio sp. nov. (in part) – Mid femur with considerable orange; dorsal surface of scape yellowish orange..... L. iangauldi Zuñiga & Valerio sp. nov. 4. Tegula yellow or light colored both anteriorly and posteriorly (Fig. 6)............... L. wahli Zuñiga & Valerio sp. nov. – Tegula dark posteriorly (Figs. 9–10)...................................................................... 5 5. Scape predominantly yellowish to light brown, especially on dorsal surface (Fig. 8).......... L. caeruliventris (Cresson) – Scape mostly dark colored on dorsal surface (Fig. 10)........................................................ 6 6. Hind tarsomeres 1–2 entirely white, or nearly so, sometimes slightly darkened at extreme apex (Fig. 13)................ 7 – Hind tarsomeres 1–2 mostly white, but dark in apical part (Figs. 11–12)......................................... 8 7. Dorsal surface of hind tibia with white extending more than half the length of the tibia, often to apex or nearly so (Fig. 7); most flagellomeres longer than wide... L. billeberhardi Zuñiga & Valerio sp. nov., L. maryjanewestae Zuñiga & Valerio sp. nov. – White on dorsal surface of hind tibia not extending more than half the length of the tibia; most flagellomeres as wide as long or wider than long.................................................... L. henrytownesi Zuñiga & Valerio sp. nov. 8. Scape black with apex and ventral side white; tegula with anterior half white (Fig. 9)......................................................................................... L. pammitchellae Zuñiga & Valerio sp. nov. (in part) – Scape brown, usually without distinct white marking on apex; tegula light colored anteriorly, but accounting for less than half the length of the tegula................................................................................ 9 9. Lateral surface of hind tibia with basal white extending no more than 0.25 × length of tibia (Fig. 12)..................................... L. hugokonsi Zuñiga & Valerio sp. nov., L. sondrawardae Zuñiga & Valerio Zuñiga & Valerio sp. nov. – Lateral surface of hind tibia with basal white extending nearly 0.4 × the length of the tibia (Fig. 13)...................................................................................... L. jesusugaldei Zuñiga & Valerio sp. nov.

Published as part of Zuñiga, Ronald, Valerio, Alejandro A., Hanson, Paul, Smith, M. Alex, Hallwachs, Winnie & Janzen, Daniel H., 2024, Cryptic diversity of Leurus wasps (Hymenoptera: Ichneumonidae: Metopiinae), parasitoids of caterpillars in Area de Conservación Guanacaste, Costa Rica, pp. 511-531 in Zootaxa 5529 (3) on page 515, DOI: 10.11646/zootaxa.5529.3.5, http://zenodo.org/record/14022829