A new species of Megarhyssa Ashmead (Hymenoptera: Ichneumonidae: Rhyssinae) from tropical Mexico with a key to Mexican species Author Khalaim, A. I. Author Ruíz-Cancino, E. text Zootaxa 2013 3619 2 195 200 journal article 10.11646/zootaxa.3619.2.7 78c60756-c07c-4122-b1ec-da97f10369ce 1175-5326 218640 5CF3C08B-F190-4B4F-B38C-3360353BA936 Key to species of Megarhyssa occurring in Mexico 1. Metasoma laterally yellow, with broad dorsal longitudinal black stripe extending entire length of metasoma ( Fig. 7 ). Fore wing hyaline with conspicuous subapical dark mark at apex of the radial cell ( Fig. 8 ). Flagellum of antenna blackish with broad subapical pale band ( Fig. 2 ). Ovipositor sheath 3.4 × as long as fore wing ( Fig. 1 )....................... M. gratiosa sp. nov. - Metasoma with variable amount of yellow, reddish orange and black; tergites often transversely banded or with dorsal and/or lateral marks, but never with continuous median black stripe extending along entire length of metasoma. Fore wing without apical dark mark, or with radial cell darkened only at base ( Townes & Townes 1960 : Fig. 319, d–g ). Flagellum of antenna more or less entirely black, sometimes somewhat lighter in the apical half, never with contrasting pale band. Ovipositor sheath about 1.9–3.0 × as long as fore wing........................................................................... 2 2. Hind leg with coxa and tarsus entirely black, femur and tibia black in basal 0.8 and yellow in apical 0.2. Head and mesosoma black with yellow markings ( Kasparyan 2002: Figs 1, 2 ). Metasoma extensively black, tergites 1 and 2 with pre-apical dorsomedian yellow marks, tergites 3+ with lateral yellow markings ( Kasparyan 2002: Figs 1, 3 ). Malar space 1.4 × as long as apical width of mandible. Ovipositor sheath 1.9 × as long as fore wing. [Distribution: Central Mexico (State of Mexico )]......................................................................................... M. verae Kasparyan, 2002 - Hind leg predominantly brownish orange with yellow marks. Head and mesosoma predominantly yellow and brown. Metasoma yellow to reddish brown, with more or less distinct transverse pre-apical yellow bands on tergites. Malar space about 0.7 × as long as apical width of mandible. Ovipositor sheath about 3.0 × as long as fore wing. [Distribution: southern U.S.A. from Texas to Georgia and Florida, northern Mexico (Chihuahua).]................ M. macrura macrura (Linnaeus, 1771)