Stenelmis vulgaris Nomura, 1958

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 : 454-459

Stenelmis vulgaris Nomura, 1958

( Figs 2 A–C, 5)

Material examined. JAPAN: Shimane Prefecture: 3 exs. (dried with an ultrathin coating of gold), Hii-kawa (river), Shimamura, Izumo-shi, fixed in 2009, laboratory rearing by MH.

Description. Body elongate, gradually narrowing from middle to apex; convex dorsally and flattened ventrally; slightly prominent spiracles on mesothorax and abdominal segments I–VIII. Body color entirely creamcolored but dark band on base and apical margin in all segments, appendages yellowish brown. Dorsal and ventral surfaces entirely smooth, dorsum with long setae.

Head visible from above, well exposed from prothorax; as wide as long; clypeus transverse, with setae on front; a pair of spines on both sides of clypeus; vertex with minute granules and spiky setae.

Thorax not serrated on lateral sides; dorsal surface entirely smooth with simple setae. Prothorax longer than width, 2.5 times as long as mesothorax; with one ventral sclerite, procoxae closed posteriorly; scale-like setae on hind margins. Meso- and metathorax transverse; metathorax longer than mesothorax. Mesothorax with five ventral sclerites.

Abdomen 9-segmented; segments I–VIII transverse, dorsal surface entirely smooth with simple setae; pleural sclerites on segments I–VII; tergal sutures on dorso-lateral area of segments II–V but short in V; last segment (segment IX) longer than wide, gradually narrowing to apex, without longitudinal ridge, apex with a pair of spines; dorsal and ventral surfaces smooth; ventral operculum, opercular claws, and anal gills present.

Habitat. Middle to lower stream reaches; larvae live in the gravel substrate, roots of reeds or decaying wood. Identification. The larva was identified by mitochondrial DNA sequences ( Hayashi & Sota 2010). Distribution. Honshu, Shikoku , Kyushu; Korea, China.

Bibliography. Hayashi & Sota (2010: fig. 4); Hayashi & Yoshitomi (2014: figs. 6A–C, 7A–B).

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.