Astromesitius, a new genus of Mesitiinae (Hymenoptera, Bethylidae) from the Old World Author Barbosa, Diego N. Author Azevedo, Celso O. text European Journal of Taxonomy 2019 2019-12-11 587 1 20 journal article 24108 10.5852/ejt.2019.587 b1bebdfa-3977-46b4-98ae-94d891747bbb 3659973 980C8BF7-A2EB-4D20-B429-CF5C4101B45B Astromesitius thionyi gen. et sp. nov. urn:lsid:zoobank.org:act: 411E3776-71AD-4EFF-847E-334DFF06D0AC Figs 1B , 2B , 3B , 4B , 5B Diagnosis Head as long as wide. Malar space shorter than VOL, parallel. First flagellomere as long as pedicel. Frontal angle of ocellar triangle acute. Mesosoma dorsal pronotal area with anterior margin convex, anterior corner rounded and side slightly concave; longitudinal pronotal sulcus incomplete. Metapectalpropodeal complex as long as metapectal-propodeal complex half-width, without longitudinal ridge between metapostnotal median and metapostnotal-propodeal carinae; metapostnotal surface polished; posterior projection of metapectal-propodeal complex absent. Propodeal declivity coriaceous. Lateral surface of metapectal-propodeal complex coriaceous, with upper carina and posterior carina. Mesopleuron coriaceous; mesopleural suture absent. Hypopygium as long as wide; anterior stalk wide and long; lateral projection short; posterior margin with branches slender. Genitalia with paramere apex glabrous; ventral arm of paramere sinuous, slender; dorsal arm as long as ventral arm, club-shaped. Aedeagal apex aligned with paramere apex, apical margin rounded. Etymology The species is named in honour of Thiony Emanuel Simon, a friend, post-doctoral fellow of the Graduate School of Zoology at UFES and marine researcher, who died while diving in a field expedition. Material examined Holotype UNITED ARAB EMIRATES • ♂ ; Al-Ajban ; 24.36° N , 55.01° E ; 27 May–26 Jun. 2006 ; A. van Harten leg.; Malaise trap ; UFES 118956 . Paratypes UNITED ARAB EMIRATES • 1 ♂ ; 7 km S of al-Jazirat al-Hamra; 25.40° N , 55.45° E ; 8 Mar. 2005 ; A. van Harten leg.; hand collecting; UFES • 1 ♂ ; Hatta x Huwaylat ; 24.50° N , 56.09° E ; 12 Mar. 2005 ; A. van Harten leg.; hand collecting; UFES . Description BODY ( Fig. 5B ). 1.3–1.8 mm long; antenna 0.9–1.1 mm long; forewing 0.8–1.0 mm long. COLOUR. Head, clypeus, antenna, mandible, palpi, mesosoma, legs and metasoma dark castaneous, except tarsi castaneous. Wings hyaline, venation light castaneous. HEAD ( Fig. 4B ). Head as long as wide. Malar space shorter than VOL, parallel. Mandible with three sharp distal teeth. Median clypeal lobe quadrate, apical margin slightly outcurved, median clypeal carina complete, arched in lateral profile. Lateral clypeal lobe short. Antenna very long, reaching middle of metasoma; scape slightly curved; pedicel caliciform; first flagellomere as long as pedicel; flagellomeres each almost twice as long as wide; proximal ones wider subdistally; flagellomeral pubescence suberect, about 0.5 × as long as flagellomeral diameter. HE about 0.42 × LH. Frons coriaceous. Frontal angle of ocellar triangle acute. Occipital carina with surface foveolate; absent ventrally. MESOSOMA ( Fig. 1B ). Dorsal pronotal area coriaceous, shorter than wide, trapezoidal, anterior margin outcurved, anterior corner rounded, lateral margin concave, posterior margin concave; longitudinal pronotal sulcus very incomplete, restricted to anterior fifth, weakly impressed. Anteromesoscutum coriaceous, as long as mesoscutellum; longitudinal anteromesoscutal sulcus absent; notaulus deep, wide, polished, slightly incurved straight, converging posterad; parapsidal signum shallow, narrow, straight, parallel. Mesoscutum-mesoscutellar sulcus straight medially, deep, and laterally dilated; mesoscutellum coriaceous. Metapectal-propodeal disc 0.5 × as long as wide, without longitudinal ridge between metapostnotal median and metapostnotal-propodeal carinae; metapostnotal surface striate; metapostnotal median carina complete, but weak and ill-defined posteriorly; posterior projection absent. Propodeal declivity very weakly areolate with polished background, median and lateral carinae very inconspicuous. Lateral surface of metapectal-propodeal complex very weakly areolate with polished background, subdorsal and vertical carina absent. Mesopleuron weakly coriaceous; posterior oblique sulcus weak, foveolate; mesopleural suture narrow. WINGS. Forewing with Rs&M vein arched; pterostigma short, about as long as prestigmal abscissa of R1, distal margin convex. Hindwing with three distal hamuli, first hamulus widely separated from others. METASOMA. Mostly polished, tergum I mostly glabrous, subsequent terga progressively more setose laterally and posteriorly. Hypopygium as long as wide; anterior stalk wide and long; lateral projection short; posterior margin with branches short and slender ( Fig. 2B ). GENITALIA ( FIG. 3B ). Paramere apex glabrous; ventral arm of paramere sinuous, slender; dorsal arm as long as ventral arm, club-shaped. Cuspis ventral arm aligned with dorsal arm apex, slender; dorsal arm wide. Aedeagus slender, with apex aligned with paramere apex, apical margin rounded, lateral margin of basal portion slightly convex. Apodeme parallel, base straight. Remarks The species Astromesitius thionyi gen. et sp. nov. is slightly similar to A. indistintus , with which it shares the absence of a longitudinal ridge between the metapostnotal median carina and metapostnotalpropodeal suture. The new species is distinguished from all the other species of Astromesitius gen. nov. by the coriaceous body surface; the polished metapostnotal-propodeal complex surface; the metapostnotal median carina incomplete; the coriaceous propodeal declivity and lateral surface of the metapostnotalpropodeal complex; the genitalia with sinuous paramere ventral arm. Astromesitius thionyi gen. et sp. nov. is the smallest species of the genus and the characteristics cited above are exclusive to this species among Astromesitius gen. nov. species; thus we did not doubt the validity of a new species. Distribution United Arab Emirates .