Dissomphalus geanus Mugrabi & Azevedo

MUGRABI, DANIELE F. & AZEVEDO, CELSO O., 2013, Revision of Thai Dissomphalus Ashmead, 1893 (Hymenoptera, Bethylidae), with description of twenty four new species, Zootaxa 3662 (1), pp. 1-73 : 53-54

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https://doi.org/ 10.11646/zootaxa.3662.1.1

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Dissomphalus geanus Mugrabi & Azevedo

sp. nov.

Dissomphalus geanus Mugrabi & Azevedo , sp. nov.

( Figs 81–82, 122, 212–213)

Description. MALE. Body length 1.67 mm. LFW 1.33 mm. Maximum wing width 0.53 mm. Color. Head black; mesosoma and metasoma dark castaneous.

Head. Mandible with two apical teeth. Clypeus with median lobe ill-defined; with one tooth, median tooth rounded; median carina absent. Ratio of first four antennal segments about 14:4:4:5. Frons weakly coriaceous, punctures small. LH 1.1 × WH, WF 0.63 × WH, WF 1.31 × HE, OOL 1.5 × WOT, DAO 0.38 × WOT, posterior ocelli distant from vertex crest 0.33 × DAO, frontal angle of ocellar triangle acute, VOL 0.85 × HE. Vertex crest weakly convex. Occipital carina not visible in dorsal view.

Mesosoma. Pronotal disc strongly coriaceous, anterior margin ecarinate. Notauli shallow, incomplete, restricted to anterior fourth of mesoscutum, evenly narrow, converging posterad. Propodeal disc 0.82 × as long as wide; basal triangle rugulose, posterolateral area rugulose; median carina posteriorly incomplete; lateral margins

Metasoma. Tergite II without tergal process ( Figs 81–82). Hypopygium with median stalk 0.86 × as long as hypopygeal plate; median stalk narrow; corner of anterior margin angular; lateral stalk of hypopygium 0.09 × as long as median stalk; posterior margin concave; corner rounded ( Fig. 122).

Genitalia ( Figs 212–213). Genital ring produced, each half straight in dorsal view. Basiparamere with dorsal surface much wider apicad, slightly narrower than ventral surface. Paramere with basal area as wide as basiparamere apex, ventral margin slightly excavated forming a projection with apex rounded; apex rounded; apical margin strongly concave in ventral view, not curved. Basivolsella glabrous. Aedeagus 3.18 × as long as wide; dorsal body of aedeagus narrower apically, narrowing abruptly apicad, lateral margin weakly convex, parallel, not curved dorsad, apex with one pair of outer lobe; base of dorsal body weakly sclerotized, strongly concave, with median region angulate; ventral ramus of aedeagus surpassing half length of dorsal body, reaching base of apical lobe of dorsal body, lateral margin of ventral ramus weakly convex, wider medially and base much narrower than apex. Apodeme not extending beyond genital ring.

FEMALE unknown.

Material examined. Holotype, ♂. THAILAND. Ubon Ratchathani: Pha Taem NP, First level-Huay Sa-nhom waterfall, 15°27.407’N 105°34.867’E, 230 m, Malaise trap, 16–23.v.2007, Sorawit Mingman leg., T2191 GoogleMaps . Paratypes: THAILAND. Malaise trap, Loei : 1 ♂ Phu Kradueng NP, Road to Ta Krong waterfall of Na Noy Forest Unit, 16°48.913’N 101°47.634’E, 265 m, 14–20.xi.2006, Suthin Gong-lasae leg., T1073 GoogleMaps . Phetchabun: Nam Nao NP, Forest protection unit , 1 ♂ Huay Pralard cave , 16°44.986’N 101°27.874’E, 711 m, 15–22.i.2007, Noopean Hongyothi leg., T1623 GoogleMaps ; 1 ♂ Heliport , 16°43.113’N 101°35.134’E, 889 m, 25.xii.2006 – 1.i.2007, Noopean Hongyothi & Leng Janteab leg., T1437 GoogleMaps ; Khao Kho NP , 1 ♂ Mix deciduous, 16°39.589’N 101°8.185’E, 168 m, 12– 19.i.2007 Somchai Chachumnan & Saink Singtong leg., T1395 GoogleMaps ; 1 ♂ Mixed deciduous forest, 16°32.539’ N 101°2.483’E, 524 m, 26.xii.2006 – 2.i.2007, T1188 GoogleMaps . Ubon Ratchathani: Pha Taem NP , 1 ♂ Rong Hi , 15°40.016’N 105°30.502’E, 246 m, 14–21.i.2007, Thongkam & Pakdee leg., T1480 GoogleMaps ; 1 ♂ Don Rong pond 15°24.582’N 105°30.935’E, 250 m, 25.viii–2.ix.2006, Bunlu Subsiri leg., T471 GoogleMaps .

Variations. Body length between 140 and 1.82 mm; LFW between 1.27 and 1.35 mm; maximum wing width between 0.43 and 0.57 mm.

Remarks. Dissomphalus geanus sp. nov. is similar to D. robus sp. nov. because of the following characteristics: LFW 1.33 mm; maximum wing width 0.53 mm; frontal carina as long as clypeus; clypeal median lobe absent; pedicel as long as flagellomere I; WF 1.31 × HE; DAO 0.38 × WOT; distance between posterior ocellus and vertex crest 0.33 × DAO; anterior ocellus 0.18 × as wide as WF; pronotal declivity low; dorsal surface of basivolsella shorter than ventral surface; digitus long; aedeagal dorsal body narrowing abruptly at base and apex. However, D. geanus sp. nov. differs from D. robus sp. nov. as follows: hypopygium trapezoidal, median stalk narrow and apex slightly bulging; basiparamere with apical region 2.00 × wider than basal region, dorsal surface shorter than ventral surface; paramere with basal region as wide as basiparamere apex, ventral surface divided; aedeagal ventral ramus elliptical and wide, slightly longer than half length of dorsal body, and reaching base of apical lobe of dorsal body.

The very wide ventral surface of basiparamere of D. geanus sp. nov. and low sclerotization of the genital structures make it difficult to visualize dorsal body. So, part of the description of this structure was performed based on the image obtained by SEM.

Distribution. Thailand (Loei, Phetchabun and Ubon Ratchathani).