Erostrata Savchenko, 1976

Kato, Daichi, Tachi, Takuji & Gelhaus, Jon, 2018, Revision of the subgenus Dicranomyia (Erostrata) Savchenko, 1976 (Diptera, Limoniidae) of Japan, Zootaxa 4441 (1), pp. 181-194 : 193

Key to Japanese species of the subgenus Erostrata Savchenko

1. Thorax with pleuron pale yellow on ventral half, much paler than dorsal half ( Fig. 40 )............... D. yazuensis sp. nov.

- Prescutum and pleuron pale brown to dark brown ( Figs. 35–39 )................................................. 2

2. Vertex with silver pruinosity on anterior part; abdominal sternites and genital segments distinctly paler than abdominal tergites; gonostylus with a black spine or lobe near tip ( Figs. 14 , 26 ).................................................... 3

- Vertex without silver pruinosity; abdomen uniformly brown to dark brown; gonostylus with many spines or strong setae near tip ( Figs. 3 , 9 )........................................................................................ 4

3. Prescutum without a dark stripe; distal half of gonostylus narrowed to subacute tip, ventral surface of apical region without dense fine setae ( Fig. 26 )......................................................... D. tabashii ( Alexander, 1934)

- Prescutum usually with a dark stripe; gonostylus stout and reniform, ventral surface of apical region with dense fine setae ( Fig. 14 )................................................................................ D. reniformis sp. nov.

4. Male genitalia ( Figs. 20–22 ) with ventromesal lobe of gonocoxite short and stout, about as long as wide; gonostylus concaved on distal 1/3; paramere with a ridge-like extension on outer margin at base of mesal-apical lobe....... D. submelas sp. nov.

- Male genitalia ( Figs. 4–6 ) with ventromesal lobe of gonocoxite slender, 1.5–2 times as long as wide; gonostylus not as above; paramere smooth near outer margin at base of mesal-apical lobe................................................ 5

5. Male genitalia ( Fig. 4 ) with gonostylus weakly narrowed toward tip, apex truncated...... D. globithorax Osten Sacken, 1869

- Male genitalia ( Fig. 7 ) with gonostylus slightly wider distally than at base, apex produced into a small lobe on outer edge.............................................................................. D. globulithorax Alexander, 1924

Figures

FIGURES 35–40. Adults of Dicranomyia (Erostrata) spp. 35: D. (E.) globithorax; 36: D. (E.) globulithorax; 37: D. (E.) submelas sp. nov.; 38: D. (E.) reniformis sp. nov.; 39: D. (E.) tabashii; 40: D. (E.) yazuensis sp. nov. Scale bars = 2 mm.

FIGURES 14–19. Male genitalia and female ovipositor of Dicranomyia (Erostrata) reniformis sp. nov. (paratypes, Japan, Fukuoka). 14: Male genitalia in dorsal view; 15: Internal structure of male genitalia in dorsal view; 16: Paramere of male genitalia in outer view; 17: Female ovipositor in lateral view; 18: Sternite 8 and hypogynial valve in ventral view; 19: Furca in ventral view. Scale bars = 0.1 mm.

FIGURES 26–28. Male genitalia of Dicranomyia (Erostrata) tabashii (non-type, Japan, Tottori). 26: Male genitalia in dorsal view; 27: Internal structure in dorsal view; 28: Paramere in outer view. Scale bars = 0.1 mm.

FIGURES 1–3. Head in lateral view and wing. 1: Dicranomyia (Erostrata) submelas sp. nov.; 2: D. (E.) tabashii; 3: D. (E.) globithorax. Scale bars 1–2 = 0.1 mm, 3 = 1 mm. Abbreviations: fl, flagellum; lb, labellum; pd, pedicel; pl, palpus; rs, rostrum; sc, scape.

FIGURES 4–13. Male genitalia of Dicranomyia (Erostrata) globithorax and D. (E.) globulithorax, and female ovipositor of the former species. 4–6, 11–13. D. globithorax (non-type, Japan, Aomori). 7. D. globulithorax (holotype), 8–10, D. globithorax (non-type, USA, Pennsylvania). 4: Male genitalia in dorsal view; 5: Internal structure of male genitalia in dorsal view; 6: Paramere of male genitalia in outer view; 7: Gonostylus in dorsal view; 8: Paramere in dorsal view; 9: Paramere, outer surface; 10: Internal sac on male sternite 7 (non-type, Canada); 11: Female ovipositor in lateral view; 12: Sternite 8 and hypogynial valve in ventral view; 13: Furca in ventral view. Scale bars = 0.1 mm. Abbreviations: aed, aedeagus; cer, cercus; fu, furca; gc, gonocoxite; gs, gonostylus; hyp vlv, hypogynial valve; ma l, mesal-apical lobe; S8, sternite 8; T8–10, tergites 8–10; vm l, ventromesal lobe.

FIGURES 20–25. Male genitalia and female ovipositor of Dicranomyia (Erostrata) submelas sp. nov. 20: Male genitalia (paratype, Japan, Aichi) in dorsal view; 21: Internal structure of male genitalia in dorsal view; 22: Paramere of male genitalia in outer view; 23: Female ovipositor (paratype, Japan, Fukuoka) in lateral view; 24: Sternite 8 and hypogynial valve in ventral view; 25: Furca in ventral view. Scale bars = 0.1 mm.