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