77 Acta Soc. Zool. Bohem. 73: 77–86, 2009 ISSN 1211-376X Taxonomic notes on the Oomyzus sempronius species group (Hymenoptera, Eulophidae, Tetrastichinae), with descriptions of new species Zoya A. YEFREMOVA & Ekaterina N. YEGORENKOVA Ul’yanovsk State Pedagogical University, Ul’yanovsk 432700, Pl.100-letyia Lenina 4, Russia; eulophids@mail.ru; egorenkova80@mail.ru Received xxxx, 2009; accepted xxxx, 2009 Published xxxx, 2009 Abstract. Two new species, Oomyzus hemerobii sp. nov. and O. rujumensis sp. nov. from Yemen, both belonging to the sempronius group of the genus Oomyzus Rondani, are described. The diagnostic characters of this species group that are used for taxonomic purposes are illustrated in 18 figures and the relationships of this species group with that of other groups are discussed. A key to species of the sempronius group is provided and new geographical records cited. Taxonomy, new species, key, Hymenoptera, Eulophidae, Oomyzus, sempronius species group, Palaearctic and Afrotropical regions INTRODUCTION The genus Oomyzus was described by Rondani in 1870. Species of this genus are larval and pupal parasitoids of Coleoptera (families Curculionidae and Coccinellidae), occasionally of Neuroptera, Diptera and Lepidoptera (Graham 1991). Genus Oomyzus includes 20 species worldwide (Noyes 2009). In the Afrotropical region, Oomyzus sokolowskii (Kurdjumov, 1912) (Burks 1979, Do- menichini 1966, Fry 1989, Graham 1991, Harten 1991, Kfir 1997, La Salle 1993) and Oomyzus sempronius (Erdös, 1954) are described from Yemen (Yefremova & Yegorenkova 2009). Five species are known from the Oriental region (Khan & Shafee 1981, Husain & Khan 1986, Gra- ham 1991, Kamijo 2000, Narendran et al. 2001), 16 from the Palaearctic region (Graham 1991, Hedqvist 2003, Kostjukov 1978, Sheng & Zhu 1998), three from Australasian region (Bouček 1988, Meiners & Hilker 2000) and four from the Nearctic region (Peck 1963, La Salle 1994). Two species, Oomyzus incertus (Ratzeburg, 1844) and O. gallerucae (Fonscolombe, 1832), were introduced into USA. The Palaearctic species are keyed out by Graham (1991). This genus is quite distinctive in having the following characters: mid lobe of mesoscutum lacks a median line, with 1 row of 2–5 adnotaular setae on each side; submedian lines on scutellum weak or absent; propodeum medially longer than dorsellum; SMV with 1 seta; gaster ovate, shorter than thorax; body black or brown with a metallic tint. Graham (1991) established three species-groups within the genus Oomyzus: the sempronius-group, the incertus-group and the gallerucae-group. In the sempronius-group he includes only one species, Oomyzus sempronius, but mentions several species from Asia and Africa, which were examined by him and could be also be included in this group. The species from Yemen, newly described in this paper, belong to the sempronius-group.