Cerodontha ( Dizygomyza ) tumefacta, Fu & Shi & Wang, 2026

Fu, Xin-Ting, Shi, Li & Wang, Shi-Mingzhe, 2026, Three new Cerodontha species from Inner Mongolia and Qinghai with a checklist of thirty-two Chinese species (Diptera, Agromyzidae), ZooKeys 1266, pp. 55-101 : 55-101

Cerodontha ( Dizygomyza) tumefacta sp. nov.

Figs 10 A – L , 11 A – K

Type material.

China, Qinghai Province: Holotype: • ♂ ( IMAU), Qilian County, Ebu Town, the southern slope of Longkongdaban , 3445 m, 38°04'29.18"N, 100°38'41.05"E, 31. VII. 2021, leg. Li Shi . Paratypes: • 6 ♂♂ 3 ♀♀ ( IMAU), same data as for holotype ; • 2 ♂♂ ( IMAU), Qilian County, Lujiaogou , 3417 m, 38°06'31.22"N, 100°28'42.33"E, 01. VIII. 2021, leg. Li Shi . DNA sequence number PX 103171 from GenBank.

Diagnosis.

Frons and parafacial strongly projecting above eye in lateral view. Fronto-orbital plate obviously shining and inner margin yellow, three (rarely 4 or 5) ori and two ors. Lunule broad, wider than high and distinctly projecting above frons in lateral view. Mesonotum moderately shiny, 1 + 3 or 2 + 3 dc, acr in four irregular rows. Legs black, fore femora with knees dark yellow. Wing with the ultimate and penultimate sections of M 4 in proportion of 1.2: 1. Calypter yellow, margin and fringe brownish. The mesophallus and distiphallus wrapped in a layer of membrane with dark dots; distiphallus S-shaped, 1.8 × length of mesophallus, pale brown at apex in lateral view.

Description.

Male (Fig. 10 A – L ). Body length 2.5–3.0 mm; wing length 2.4–2.7 mm. Female (Fig. 11 A – K ). Body length 2.3–2.7 mm; wing length 2.3–2.8 mm.

Head (Fig. 10 B, C ) blackish brown. Frons and parafacial strongly projecting above eye in lateral view; frons ~ 1.7 × as wide as eye in dorsal view; fronto-orbital plate obviously shiny and inner margin yellow, ~ 2 / 5 width of frons; three (rarely 4 or 5) ori and two ors; orbital setulae sparse and long in one or two rows, reclinate or erect. Ocellar triangle wide, ocellar setae slightly weaker than ors. Lunule broad, wider than high and distinctly projecting above frons in lateral view. Antennal first flagellomere very broad with pale pubescence; arista distinctly thickened on basal 1 / 2. Facial keel wide and distinctly raised. Gena slightly yellow at middle, ~ 1 / 3 height of eye, highest point located at the rear. Clypeus yellowish; palpus black, with two prominent setae at apex.

Thorax (Fig. 10 D, E ) black. Mesonotum moderately shiny, 1 + 3 or 2 + 3 dc, acr in four irregular rows; one postsutural intra-alar, one presutural and two strong postsutural supra-alar setae. Notopleuron brown. Anepisternum with one anepisternal seta, seven long setulae and six short setulae. Katepisternum with one katepisternal seta and five long setulae. Legs black, fore femora with knees dark yellow. Wing: Costa with 2 nd (between R 1 and R 2 + 3), 3 rd (between R 2 + 3 and R 4 + 5) and 4 th (between R 4 + 5 and M 1) sections in proportion of 4.4: 1.3: 1; ultimate and penultimate sections of M 1 in proportion of 2.2: 1; r-m beyond middle of discal cell; ultimate and penultimate sections of M 4 in proportion of 1.2: 1. Calypter yellow, margin and fringe brownish. Halter yellow.

Abdomen (Fig. 10 F ) dark brown, tergites 1–6 with yellow posterior margin. Genitalia (Fig. 10 G – L ): epandrium with a pair of distinctly long claviform processes; surstylus with six spines in posterior view (Fig. 10 K ); mesophallus and distiphallus wrapped in a layer of membrane with dark dots; mesophallus cylindrical and swollen at distal 1 / 3, ~ 1.5 × length of hypophallus; distiphallus S-shaped, 1.8 × length of mesophallus, pale brown at apex in lateral view; ejaculatory apodeme broad, blade margin unclear and sperm pump pale but base of duct lightly pigmented.

Female (Fig. 11 A – K ). Lunule and facial keel narrower than that in male. First flagellomere not enlarged as the male (Fig. 11 B ). Other external characteristics same as the male except for the female terminalia. Terminalia (Fig. 11 G – K ): spermathecae circular and truncated at basal 1 / 5; ventral receptacle symmetrical, well-sclerotized at apex. Cercus with relatively long and sturdy setulae.

Distribution.

China ( Qinghai).

Etymology.

The specific name of this new species comes from the Latin tumefacta, meaning intumescent, referring to the lunule projected prominently above the frons.

Remarks.

The new species can be distinguished from other species of subgenus Dizygomyza by the lunule projecting prominently above frons and the first flagellomere very broad in male. The mesophallus and distiphallus of Cerodontha ( Dizygomyza) tumefacta sp. nov. are similar to those of C. ( D.) labradorensis from Palaearctic and Nearctic regions, but it can be separated from the latter by the mesophallus and distiphallus being wrapped in a layer of membrane with dark dots; the mesophallus being cylindrical and swollen at distal 1 / 3, ~ 1.5 × length of hypophallus; the distiphallus being S-shaped, 1.8 × length of mesophallus and pale brown at apex. In C. ( D.) labradorensis , the mesophallus is swollen at distal 1 / 3 with a medial suture in ventral view; the distiphallus is S-shaped, ~ 2.5 × length of mesophallus, and yellowish brown at the apex in lateral view.

Figures

Figure 10. Cerodontha (Dizygomyza) tumefacta sp. nov. Paratype male. A. Habitus, lateral view; B, C. Head, lateral and dorsal view; D, E. Thorax, dorsal and lateral view; F. Abdomen, lateral view; G, J. Genitalia, lateral and ventral view; H, K. Epandrial complex, posterolateral and posterior view; I, L. Ejaculatory apodeme, lateral and ventral view. Scale bars: 0.5 mm (A – F); 0.1 mm (G – L).

Figure 11. Cerodontha (Dizygomyza) tumefacta sp. nov. Paratype female. A. Habitus, lateral view; B, C. Head, lateral and dorsal view; D, E. Thorax, lateral and dorsal view; F. Abdomen, dorsal view; G, H. Spermathecae, ventral receptacle and oviscape, lateral and ventral view; I. Spermathecae; J. Proctiger, lateral and ventral view; K. Ventral receptacle, ventral view. Scale bars: 0.5 mm (A – H); 0.1 mm (I – K).