Two new species of Epirhyssa (Hymenoptera: Ichneumonidae: Rhyssinae) from Costa Rica Author Zuñiga, Ronald Guanacaste Dry Forest Conservation Fund, Sector Santa Rosa, Area de Conservación Guanacaste, Costa Rica. Author Hanson, Paul Centro de Investigación en Biodiversidad y Ecología Tropical, Escuela de Biologia, Universidad de Costa Rica, San Pedro, 11501 - 2060, San José, Costa Rica. text Zootaxa 2024 2024-02-07 5406 3 441 450 http://dx.doi.org/10.11646/zootaxa.5406.3.3 journal article 10.11646/zootaxa.5406.3.3 1175-5326 10628032 A1F77DF6-4F1B-4858-85FB-22620BCE0484 Key to Costa Rican species of Epirhyssa (females) Modified from Gauld (1991) and Gauld and Ward (1997) ; additional illustrations can be found in these publications. Epirhyssa corralesi Gauld was synonymized with E. oaxaca Porter by Khalaim et al . 2021 . 1. Fore wing without blackish mark at apex.................................................................. 2 - Fore wing with a distinct blackish mark at apex, or at least weakly infumate...................................... 9 2. Ventral part of occipital carina complete, joining hypostomal carina above base of mandible ( Fig. 1 )................... 3 - Ventral part of occipital carina absent, thus this carina does not join the hypostomal carina ( Fig. 2 ).................... 6 3. Tergite II of metasoma extensively smooth and polished, with scattered hairs only anteriorly and laterally. E. prolasia Porter - Tergite II of metasoma with alutaceous sculpture (fine wrinkling) over entire surface, and more or less uniformly covered with short hairs.......................................................................................... 4 4. Head, mesosoma and metasoma predominantly blackish brown ( Fig. 3 ). [Mesoscutum with closely spaced, coarse short dark pubescence.]............................................................................ E. curtisi Gauld - Head, mesosoma and metasoma predominantly yellowish with extensive black marks ( Fig. 4 )........................ 5 5. Tergite I at least 1.8 × as long as posterior width; propodeum with a narrow posteromedian black mark, occupying less than 1/3 the width of dorsal surface ( Fig. 5 )........................................................ E. oranensis Gauld - Tergite I less than 1.8 × as long as posterior width; propodeum with a broad posteromedian black mark, occupying more than 1/2 the width of dorsal surface ( Fig. 6 )...................................... E. leonoreae Zuñiga & Hanson , sp.n. 6. Mesoscutum with three complete longitudinal black stripes, two lateral stripes not reaching lateral margin ( Fig. 7 )........ 7 - Mesoscutum with complete longitudinal black stripe in middle and with two lateral black marks anteriorly that reach the lateral margins but do not extend posteriorly ( Fig. 8 ).............................................................. 8 7. Antennal flagellum black, except segments 5–7 or 6–7 yellowish orange; metasomal tergites VI–VII at least partially yellow ( Fig. 9 )................................................................................. E. quirosi Gauld - Flagellum dark brown, except segments 2–5 slightly paler; metasomal tergites VI–VII entirely black ( Fig. 10 )..................................................................................... E. lewisi Zuñiga & Hanson , sp.n. 8. Antennal flagellum with pale band on segments 9–13 (or 15); face usually with a blackish median vertical stripe; apical margin of clypeus with a small nipple-like median tubercle ( Fig. 11 ).................................... E. theloides Gauld - Flagellum with pale band on segments (5) 6–9 (or 10); face uniformly yellow; apical margin of clypeus with broad rounded median tubercle ( Fig. 12 )............................................................... E. praecincta Porter 9. Antennal flagellum more or less entirely black basally, without a pale submedian band and with only extreme apex slightly brownish; tergite I of metasoma moderately slender, 1.6–2.2 × as long as posteriorly broad......................... 10 - Flagellum basally pale yellowish, sometimes with a submedian pale band; tergite I of metasoma very slender, 2.4 or more × as long as posteriorly broad.............................................................................. 13 10. Mesosoma and metasoma uniformly orange, face subquadrate, as broad as medially high (from clypeofacial suture to base of antenna)................................................................................ E. porteri Gauld - Mesosoma and metasoma yellow with profuse black markings; face transverse 1.1–1.3 × as broad as medially high (from clypeofacial suture to base of antenna)................................................................... 11 FIGURES 1–2. Epirhyssa spp. , head, posterolateral view showing occipital and hypostomal carinae (modified from Gauld 1991 ). 1. Occipital carina complete. 2. Occipital carina with ventral part absent. 11. Lateral lobe of mesoscutum entirely yellow, or with a faint yellowish brown stripe, fore wing with first subdiscal cell very strongly widened distally, its distal breadth 2.4–2.7 × its basal breadth.......................... E. mexicana Cresson - Lateral lobe of mesoscutum with a longitudinal black stripe; fore wing with first subdiscal cell moderately widened distally, its distal breadth 1.5–2.1 × its basal breadth................................................................. 12 12. Apex of clypeus with a strong median tubercle; fore wing with a triangular black mark centered around distal end of Rs; distal apex of antenna slender, subapical flagellomeres about 1.2 × as broad as the central flagellomeres....... E. frohbergi Gauld - Apex of clypeus without any trace of a median tubercle; fore wing with entire distal apex blackish; distal end of flagellum slightly clavate, subapical flagellomeres about 1.5 or more × as broad as the central flagellomeres................................................................................................... E. zurquiae Gauld and Ward 13. Hind coxa yellowish orange, very long and slender, in profile about 3.4 × as long as broad; metasoma entirely orange; antennal flagellum without a submedian pale band.......................................................... E. osaensis - Hind coxa yellowish dorsally and black ventrally, moderately slender, in profile 2.7–2.9 × as long as broad; metasoma yellow and black banded; flagellum with a submedian pale band........................................ E. oaxaca Porter