Dipogon (Stigmatodipogon) tanakai Ishikawa, 1965

Shimizu, Akira, Lelej, Arkady S., Loktionov, Valery M., Nishimoto, Yutaka & Endo, Tomoji, 2018, Revision of the subgenus Stigmatodipogon Ishikawa of the genus Dipogon Fox (Hymenoptera: Pompilidae: Pepsinae), Zootaxa 4514 (1), pp. 1-22 : 18-20

6. Dipogon (Stigmatodipogon) tanakai Ishikawa, 1965

( Fig. 9 )

Dipogon (Stigmatodipogon) tanakai Ishikawa 1965: 99 , ♀ (holotype, ♀, Japan, Nikko, 26.vii.1954 (E. Tanaka) [NSMT],

examined); Ishikawa 1965: 99, ♀; Shimizu 1996: 508; Shimizu & Terayama 2016: 596.

Stigmatodipogon tanakai: Lelej & Loktionov 2012b: 11 .

Diagnosis. FEMALE. The female of this species is distinguishable from those of other species by having the frons minutely punctate with the interspaces almost smooth and strongly polished ( Fig. 9A ); and the propodeum with a sublateral narrow groove behind the stigma ( Fig. 9B ). MALE. Unknown.

Redescription. (Measurements of the holotype are given in parentheses.) FEMALE. Length: body 4.9–5.5 (4.9) mm; fore wing 4.5–4.8 (4.5) mm. Body black and strongly polished ( Fig. 9C ). Following bright-brown to ferruginous: antenna (darker above than below), clypeus apically, lateral and posterior margins of pronotum and metasomal terga, and posterior margins of sterna. Mandible yellowish-brown mostly, dark-brown basally, reddishbrown apically. Palpi ( Fig. 9D ) and tegula light brown. Legs mostly dark brown ( Fig. 9C ); fore tibia and tarsus yellowish- to bright-brown, darker above than below; mid and hind tibiae below and tarsomeres I–IV apically bright brown.

Body and legs with short greyish- to brownish-white pubescence, that being longer and denser on lower frons, clypeus, mesosomal side and sterna, and coxae. Vertex, pro- and mesonota, gena, occiput, mesosternum and coxae with a few comparatively long setae. Clypeus preapically and mandible with long bristles. Metasomal sterna and tergum V with sparse bristles. Tergum VI with dense brown bristles.

Frons ( Fig. 9A ), vertex ( Fig. 9E ) and dorsa of meso- and metanota with minute dense punctures (those on metanotum weak), interspaces on head, scutellum and metanotum being almost smooth and strongly polished and those on mesoscutum finely alutaceous. Pronotum alutaceous (appearing minute dense setiferous pores seen from some directions). Mesepisternum and lower metapleuron strongly alutaceous. Upper metapleuron finely striate. Propodeum irregularly punctate and strongly alutaceous.

Head width 1.1–1.2 (1.1) × length, 1.3–1.4 (1.4) × pronotum width. Vertex in frontal view moderately convex ( Fig. 9A ). Frons in profile gently convex, slightly protruding anteriorly, exceeding above level of clypeus ( Fig. 9D ); frontal line impressed only below. Inner orbits slightly convergent above, nearly parallel below ( Fig. 9A ). UID: MID: LID = 7.4–7.6 (7.4): 10: 9.3–9.4 (9.3). MID 0.61 (0.61) × head width. Ocellar triangle acute-angled ( Fig. 9E ), ocelli scarcely raised ( Fig. 9A ). POL: OOL = 1: 1.0–1.1 (1.0). Gena in dorsal view not developed, rather strongly receding posteriorly, its width in profile broadened below, about 0.8 × eye width ( Fig. 9D ). Clypeus as broad as LID ( Fig. 9A ), its width 2.5 (2.5) × length, with a few rather large setiferous pores preapically; apicolateral corner rounded; apical rim depressed, shortened medially, impunctate and feebly striate; apical margin widely straight. Malar space short. Flagellomere I length 1.3–1.4 (1.3) × flagellomere II length, 4.8–5.0 (4.8) × its width and 0.82–0.84 (0.82) × UID.

Pronotum slightly depressed near posterior margin ( Fig. 9E ), latter being obtusely angulate at middle; shoulder slightly bulging. Side of metanotum strongly depressed posteriorly. Metapostnotum length 0.2 (0.2) × metanotum length at midline. Propodeum length (1.1) × width, weakly convex ( Fig. 9B ) with indistinct, broad median groove.

Metasomal tergum I with long petiole. Tergum II width 0. 87–0.89 (0.87) × head width.

Fore wing ( Fig. 9F ) with pterostigma large, its length 1.8–1.9 (1.9) × SMC2 length, its width 0.88–1.0 (1.0) × SMC2 width. SMC2 length 1.8 (1.8) × width, narrowed on vein Rs by 0.68–0.71 (0.68) × its own length on vein M, receiving crossvein 1m-cu at basal 0.52–0.56 (0.56). SMC3 length 1.3–1.5 (1.5) × width, 1.0–1.2 (1.2) × SMC2 length on vein M, 0.78–1.1 (1.1) × SMC2 length on vein Rs, narrowed on vein Rs 0.55–0.66 (0.66) × by its own length on vein M, receiving crossvein 2m-cu at basal 0.31–0.34 (0.34).

Longer spur of hind tibia 0.39–0.42 (0.42) × hind tarsomere I length. Tarsomere V not enlarged, hind tarsomere V length 1.3–1.4 (1.4) × hind tarsomere IV length, its width 1.2–1.3 (1.3) × hind tarsomere IV width.

MALE. Unknown.

Material examined. JAPAN. Honshu: 1♀, 3rd Step, Mt. Fuji , Narusawa-mura , Yamanashi Pref., 30.viii.1978 (Y. T. & H. Suda) [ NSMT] .

Distribution. Japan (Honshu).

Biology. Unknown.

Figures

FIGURE 9. Dipogon (Stigmatodipogon) tanakai, holotype, ♀. A. Head, frontal view. B. Mesosoma, lateral view. C. Whole body, lateral view. D. Head, lateral view. E. Head, dorsal view and pronotum, dorsolateral view. F. Wings. Scale bars: 1 mm for C, 0.5 mm for others.