Megaphthalmoides vittatus, Iwasa, 2021

Iwasa, Mitsuhiro, 2021, Three new species and six new records of Scathophagidae (Diptera) from Japan with a key to the Japanese genera, Zootaxa 4981 (3), pp. 531-553 : 545

Megaphthalmoides vittatus sp. nov.

[Japanese name: Kurotsuno-sesuji-funbae]

( Figs 38–43 )

Type material examined. Holotype ♂, JAPAN: Kamikochi, Azumimura, Nagano Pref., Honshu , 3-4. x. 1988, leg. S. Shinonaga ( OUAVM) . Paratypes: Honshu, 1 ♂, Tôshichi Spa, Hachimantai City , Iwate Pref., 3. viii. 2013, leg. D. Kato ( OUAVM) ; 1 ♂, Hatomati-toge, Oze, Gumma Pref. 7. vii. 1951, leg. H. Hasegawa ( IAES) ; 1 ♂, Gumma Pref. , 23. ix. 1950, leg. N. Fukuhara ( IAES) .

Diagnosis. Megaphthalmoides vittatus sp. nov. can be recognized by frontal vitta with a distinct black pattern and wholly black postpedicel.

Description. Male ( Fig. 38 ). Head ( Fig. 39 ): eyes reddish brown; frontal vitta with a distinct black pattern; fronto-orbital plate yellow; ocellar triangle dark; face yellow and shiny; parafacial very narrow; gena and postgena yellow slightly with silvery microtrichose; occiput yellow and shiny; postpedicel ( Fig. 40 ) black and approximately 2 times as long as wide; pedicel yellow; arista short-haired; palpus yellow and filiform, sparsely with short setulae anteroventrally; proboscis yellow to brown; vibrissal angle with 1 strong seta and 1 subvibrissae. Chaetotaxy (black): 2-3 fr (medioclinate), 2 or (1 proclinate, 1 latero-reclinate), 1 oc, 1 vti, 1 vte, 1 poc. Thorax: wholly yellow and shiny; scutum and prescutum with weak longitudinal stripe; proepisternum bare; anepisternum, katepisternum and anepimeron sparsely covered with short hair-like setulae; meron and katatergite bare; metanotum bare and slightly silvery microtrichose. Chaetotaxy (black): 2 pprn, 2 npl, 1+2 ial; 2 sa, 2 pa, 2+3 dc, 1 bsc, 1 apsc; 1 prepm, 2-1 (2 long, 1 short) anepst, 1 kepst. Wings: hyaline, slightly tinged with brown; veins brown; veins R 4+5 and M 1 almost parallel; vein A 1 +CuA 2 reach wing margin; calypter yellow with hairs marginally; halter yellow. Legs: coxae yellow to light brown; femora and tibiae yellow; fore femur yellow, ventrally and posterodorsally covered with hairs and setulae; mid femur apically black, with several a setulae; hind femur apically black with a row of ad setae; fore tibia with 1 p seta at basal two-fifths, 1 d seta near half and 1 preapical pd and 1 preapical d; mid tibia with 1 ad and 1 av setae at distal one-third and 1 apical av and 1 apical pv; hind tibia with 3 ad and 3 pd setae at regular intervals and 1 apical av; tarsi dark brown. Abdomen: tergites brown to dark brown and shiny, covered with hair-like setulae and distinct setae at posterior margin of each segment; sternite V ( Fig. 41 ) bilobate posteriorly, covered with long and short setae on lobes; epandrium ( Figs 42, 43 ) sparsely covered with short setae; surstylus ( Figs 42, 43 ) long and slender, tapered apically; aedeagus stout and sclerotized; epiphallus rod-shaped and tapering apically; paramere comparatively thick with 1 short setula posteroventrally; hypandrium sclerotized and rounded, rhombus-shaped; cercus ( Figs. 42, 43 ) somewhat elongated, covered with hair-like setulae.

Length (♂). Body, 5.0–5.2 mm; wings, 5.8 mm.

Female. Unknown.

Distribution. Japan (Honshu).

Etymology. The scientific name derives from the Latin vitta meaning band, referring the presence of a distinct black band on the frons of the head.

Remarks. This species is closely similar to M. unilineatus (Zetterstedt) , but can be distinguished from it by characteristics mentioned in the following key.

Figures

FIGURES 38–43. Megaphthalmoides vittatus sp. nov. 38, Male adult, left lateral view; 39, Head, dorsal view; 40, postpedicel and pedicel, left lateral view; 41, Male sternite V, ventral view; 42, Male terminalia, left lateral view; 43, Male terminalia, posterior view.