Georissus (Neogeorissus)

Fikáček, Martin, Delgado, Juan A. & Gentili, Elio, 2012, The Hydrophiloid beetles of Socotra Island (Coleoptera: Georissidae, Hydrophilidae), Acta Entomologica Musei Nationalis Pragae 52, pp. 107-130 : 116

Georissus (Neogeorissus) sp.

Material examined. SOCOTRA: 1 ♀ ( NMPC): Dixiam plateau, wadi Esgego, 12°28′09″N 54°00′36″E, 300 m a.s.l., 2.–3.xii.2003, lgt. P. Kabátek ; 1 ♀ ( CULS): same locality and date, lgt. J. Farkač ; 1 ♀ ( NMPC): Zemhon area , 12°30′58″N 54°06′39″E, 270–350 m a.s.l., at light, 3.–4.ii.2010, lgt. J. Purchart & J. Vybíral. MAINLAND YE- MEN: 1 J ( NMPC): Lahj gov., vadi Am Rija, W of Lahj Al Hutah by road, 13°01′57″N 44°33′30″E, 297 m a.s.l., 25.–26.x.2007. lgt. A. Reiter ; 1 spec. ( NMPC): wadi Anis 60 km SW of Sana’a, 15°00′N 44°09′E, 1522 m a.s.l., 7.x.2005, lgt. S. Kadlec .

Comments. The species belongs to the G. costatus species group sensu DELÈVE (1967a,b) based on the pronotal sculpture, even elytral intervals higher than odd ones, and the coloration at least partly metallic (strongly so on the head and pronotum, weaker metallic tint is present on elytra which are otherwise paler than rest of the body, reddish to dark reddish brown with dark base and darker spots at midlength of intervals 1–2 and in basal third of intervals 5–6). Three females from Socotra Island agree in external morphology and coloration to the specimens from southern mainland Yemen with which they may be conspecific. All six examined specimens belong to the African complex of rather large species with very distinctly elevated even elytral intervals, represented in Africa by five species: G. intermedius Paulian & Legros, 1943 ( Chad) , G. fairmairei Alluaud, 1902 ( Democratic Republic of the Congo), G. marlieri Delève, 1967 ( Namibia, Zaire), G. renaudi Delève, 1967 ( Chad) and G. metallicus Paulian & Legros, 1943 ( Chad, Guinea) (see DELÈVE 1967b). The aedeagus of the male from mainland Yemen differs from all these species except G. marlieri by narrow and elongate phallobase, but is slightly smaller (0.41 mm versus 0.46 mm in the types of G. marlieri ), and the Yemeni specimens also slightly differ from G. marlieri in the basally narrower elytra. Without the comparison of longer series from Socotra and mainland Yemen (not currently available) with those from Africa, we are not able to assign the male from continental Yemen to G. marlieri reliably, and the identity of the Socotran specimens remains unclear as well, pending the collecting of males. However, the Yemeni and Socotran specimens clearly differ from G. chameleo Fikáček & Trávníček, 2009 from the United Arab Emirates (which also belongs to G. costatus species group, see FIKÁČEK & TRÁVNÍČEK (2009)) by the morphology of male genitalia as well as the body size and form, and the above specimens therefore represent the second species of the genus Georissus from the Arabian Peninsula.