Stenelmis

Hayashi, Masakazu, Kamite, Yuuki, Kobayashi, Takuya & Sota, Teiji, 2016, Description of larvae of genera Stenelmis, Ordobrevia and Nomuraelmis (Coleoptera: Elmidae: Elminae) of Japan with their molecular taxonomy, Zootaxa 4178 (4), pp. 451-480 : 473-474

Key to larvae of species of Japanese Stenelmis , Ordobrevia , Nomuraelmis , and related genera

1. Procoxal cavities not closed posteriorly, without sclerite.................................... Other genera of Elmidae

- Procoxal cavities closed posteriorly, with sclerite(s) ( Figs 5 B, 6B)............................................. 2

2. Body flat, slightly convex dorsally and flattened ventrally; meso- and metathorax and abdominal segments I–VIII with blade- like lateral projections on both sides................................................... Leptelmis gracilis Sharp

- Body elongate, semi-cylindrical, gradually narrowing from middle to apex; convex dorsally and flattened ventrally...... 3

3. Last abdominal segment with large flat slope on dorsum; body color dark brown dorsally and cream ventrally, with light spots on head, pro- and mesothorax, dark spots on side of each abdominal segments I–VII.... .. Graphelmis shirahatai (Nomura)

- Last abdominal segment semi-conical without flat slope on dorsum ( Figs 5 E, 6E).................................. 4

4. Body surface entirely smooth ( Figs 2 A–C, 3D–J)............................................................ 5

- Boby surface entirely or partly not smooth................................................................. 8

5. Body color entirely cream-colored, but with dark band on basal and apical margins in all segments ( Figs 2 A, B).......................................................................................... Stenelmis vulgaris Nomura

- Body color entirely orange ( Fig. 3 D–J).................................................................... 6

6. One or two teeth on apico-lateral margin of abdominal tergites I–VIII ( Fig. 11 H); Scale-like setae on apical margins of thorax and abdominal segments I–VIII ( Fig. 11 C)............................................. Ordobrevia gotoi Nomura

- Three to five teeth on apico-lateral margine of abdominal tergites I–VIII ( Figs 10 H, 12H)........................... 7

7. Prothorax with long brush-like setae ( Figs 12 A, G); brush-like setae on apical margins of thorax and abdominal tergites I–VIII........................................................................... Ordobrevia maculata (Nomura)

- Prothorax with short brush-like setae ( Figs 10 A, G); scale-like setae on apical margins of thorax and abdominal tergites I–VIII............................................................................... Stenelmis hayashii M. Satô

8. Ventral surface of abdominal segments I–VIII not smooth ( Figs 2 K, 4I, 7D)...................................... 9

- Ventral surface of abdominal segments I–VIII smooth ( Figs 3 M, 4C, 13D)....................................... 11

9. Ventral surface of last segment not smooth ( Figs 4 I, L, 15F), apical spines of last segment slightly sharpened ( Fig. 15 H)............................................................................. Nomuraelmis amamiensis M. Satô

- Ventral surface of last segment smooth ( Figs 4 F, 13F, 14F), apical spines of last segment clarity sharpened ( Fig. 14 E).... 10

10. Apical spines of last abdominal segment large ( Figs 6 E, 7E, 9E)................................................................................. Stenelmis nipponica Nomura , Stenelmis hisamatsui M. Satô , Stenelmis aritai M. Satô

- Apical spines of last abdominal segment small ( Fig. 8 E)................................. Stenelmis ishiharai M. Satô

11. Blunt spines on tergite of last abdominal segment in middle area ( Fig. 13 E)........... Ordobrevia foveicollis (Schönfeldt)

- Sharp spines on tergite of last abdominal segment ( Fig. 14 E)........................ Ordobrevia amamiensis (Nomura)

Figures

FIGURE 2. Larvae of Stenelmis of Japan. A – C, S. vulgaris Nomura; D – E, S. nipponica Nomura; F – H, S. hisamatsui M. Satô; I – K, S. ishiharai M. Satô. A, D, F, I, dorsal view; B, E, G, J, lateral view; C, H, K, ventral view. Scale bars: 1.0 mm.

FIGURE 3. Larvae of Stenelmis and Ordobrevia of Japan. A – C, S. aritai M. Satô; D – F, S. hayashii M. Satô; G – H, O. gotoi Nomura; I – J, O. maculata (Nomura); K – M, O. foveicollis (Schönfeldt). A, D, G, I, K, dorsal view; B, E, H, J, L, lateral view; C, F, M, ventral view. Scale bars: 1.0 mm.

FIGURE 4. Larvae of Ordobrevia and Nomuraelmis of Japan. A – F, O. amamiensis (Nomura) (A – C, immature larva from Amami-Ôshima Is.; D – F, mature larva from Iriomotejima Is.); G – L, N. amamiensis M. Satô (G – I, mature larva from Amami- Ôshima Is.; J – L, immature larva from Okinawajima Is.).

FIGURE 5. SEM photographs of Stenelmis vulgaris Nomura (Izumo, Shimane Pref.). A, B, head and thorax; C, D, abdominal segments II – V; E, F, abdominal segments VIII and IX. A, C, E, dorsal view; B, D, F, ventral view. Scale bars: 200 µm.

FIGURE 6. SEM photographs of Stenelmis nipponica Nomura (Nanbu, Tottori Pref.). A, B, head and prothorax; C, D, meso- and metathorax and abdominal segments I – II; E, F, abdominal segments VIII and IX; G, H, granules on prothorax. A, C, E, G, H, dorsal view; B, D, F, ventral view. Scale bars: 20 µm in G; 200 µm in others.

FIGURE 8. SEM photographs of Stenelmis ishiharai M. Satô (Ishigakijima Is., Okinawa Pref.). A, B, head and pro- and mesothorax; C, meso- and metathorax and abdominal segments I – II; D, abdominal segment II – VI; E, F, abdominal segments VIII – IX; G, H, granules on prothorax. A, C, E, H, dorsal view; G, lateral view; B, D, F, ventral view. Scale bars: 100 µm in G; 200 µm in others.

FIGURE 10. SEM photographs of Stenelmis hayashii M. Satô (Amami-Ôshima, Kagoshima Pref.). A, B, head and prothorax; C, abdominal segments II – V; D, abdominal segments III – V; E, F, abdominal segments VIII – IX; G, setae on prothorax; H, spines on apico-lateral margin of abdominal segment VII. A, C, E, G, dorsal view; H, lateral view; B, D, F, ventral view. Scale bars: 50 µm in G and H; 200 µm in others.

FIGURE 11. SEM photographs of Ordobrevia gotoi Nomura (Izumo, Shimane Pref.). A, B, head and prothorax; C, thorax and abdominal segments I – III; D, abdominal segments I – V; E, F, abdominal segments VIII – IX; G, setae on prothorax; H, spines on apicaolateral margin of abdominal segment VII. A, C, E, G, dorsal view; H, lateral view; B, D, F, ventral view. Scale bars: 20 µm in G; 50 µm in H; 200 µm in others.

FIGURE 12. SEM photographs of Ordobrevia maculata (Nomura) (Izumo, Shimane Pref.). A, B, head and prothorax; C, thorax and abdominal segments I – III; D, abdominal segments II – V; E, F, abdominal segments VII – IX; G, setae on prothorax; H, spines on apico-lateral margin of abdominal segment VII. A, C, E, G, dorsal view; H, lateral view; B, D, F, ventral view. Scale bars: 20 µm in G; 100 µm in H; 200 µm in others.

FIGURE 13. SEM photographs of Ordobrevia foveicollis (Schönfeldt) (Dogo Is., Shimane Pref.). A, B, head and prothorax; C, D, abdominal segments I – IV; E, F, abdominal segments VIII – IX; G, setae on prothorax; H, spines on apico-lateral margin of abdominal segment VII. A, C, E, G, dorsal view; H, lateral view; B, D, F, ventral view. Scale bars: 50 µm in G, H; 200 µm in A, B, F; 500 µm C – E.

FIGURE 14. SEM photographs of Ordobrevia amamiensis (Nomura) (Kumejima Is., Okinawa Pref.). A, B, head and prothorax; C, thorax and abdominal segments I – III; D, thorax and abdominal segments I – II; E, F, abdominal segments VIII – IX; G, setae on prothorax; H, spines on apico-lateral margin of abdominal segment VII. A, C, E, G, dorsal view; H, lateral view; B, D, F, ventral view. Scale bars: 20 µm in G; 50 µm in H; 200 µm in others.

FIGURE 15. SEM photographs of Nomuraelmis amamiensis M. Satô (Okinawajima Is., Okinawa Pref.). A, B, head and prothorax; C, abdominal segments III – V; D, Mesothorax and abdominal segments I – II; E, F, abdominal segments VIII – IX; G, setae on prothorax; H, small spine (an arrow) on abdominal segment IX. A, C, E, G, H, dorsal view; B, D, F, ventral view. Scale bars: 20 µm in G; 50 µm in H; 200 µm in others.