Niponius impressicollis: Ohara, 1994, 68.
Nioponius impressicolis Lewis, 1885b: 333 [Japan, Yuyama, in Higo to Junsai in Yezo (= Kyûshû to Hokkaidô)]; Gardner, 1926: 2; Reichardt, 1929b: 274, 273; Gardner, 1935: 5; Reichardt, 1941: 69; Nakane, 1963: 67, pl. 34, fig. 3; Kryzhanovskij and Reichardt, 1976: 77 [key, description]; Hisamatsu, 1985: 219, pl. 40, fig. 3.
Japanese name: Hoso-emma-mushi.
Description. Biometric data are given in Table 7. Body cylindrical, moderately stout. Cuticle shining, black; tarsi, antennae and projection of epistoma dark rufopiceous.
Projection of epistoma (Fig. 43A, C) moderately stout and long, its apex strongly carinate and dorsal surface with two or three transverse carinae. Head densely with transverse rugae on apical third; median third of the surface sparsely covered with moderate punctures, the punctures separated by two to five times their diameter, with other fine punctures intermingled; basal third finely and sparsely punctate; depression on mid line deeply present on apical half.
Pronotum completely with marginal stria on lateral side, the stria strongly carinate; surface with an excavation (Fig. 43D, E) on each mediolateral side, and sparsely covered with large, round and deep punctures which are irregularly scattered, and with other fine punctures sparsely intermingled among the large ones.
Epipleura of elytra completely with marginal elytral stria, which is carinate and of which the apical end attains to the apical fifth; area between epipleural margin and elytral marginal stria impunctate and extremely finely strigate. First dorsal stria present on basal fourth and strongly carinate, its basal end deeply excavate. Second to 5th dorsal striae almost obsolete, being represented by rows of coarse punctures. Sutural stria strongly impressed and represented by a row of longitudinal coarse punctures on basal two-thirds. Surface of elytra somewhat convex on humeral area, and deeply and transversely excavated near the basal margin; represented by rows of coarse punctures; intervals among the rows sparsely clothed with fine punctures on basal half, and densely on apical half, the punctures becoming coarser on apical third, and in lateral area these punctures somewhat much denser.
Propygidium (Fig. 43G) with four large, round, shallow and transversely placed foveae which become shallower posteriorly; surface sparsely covered with coarse punctures, which are as coarse as elytral ones, and other fine punctures densely intermingled among the coarse ones. Pygidium (Fig. 43G) with a large, round, and somewhat deep fovea behind each basal corner; inside of the fovea sparsely and moderately punctate; surface coarsely punctate on median area, the punctures separated by three to four times their diameter and becoming finer anteriorly, and other fine punctures sparsely intermingled among coarse ones, the fine ones becoming denser apically and laterally.
Antennal grooves (Fig. 43B) deep under eyes. Mid line of underside of head deeply excavate, its basal end beyond transverse line. Surface of underside of head shining, sparsely and finely punctate on apical half, and evenly clothed with fine punctures which are separated by two to three times their diameter on basal half.
Table 7. Biometric data of Niponius impressicollis Lewis.
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HOW 0.57-0.70 (0.65±0.021) 5
HW 1.09-1.25 (1.19±0.026) 5
PW 1.30-1.56 (1.46±0.042) 5
PL 1.27-1.66 (1.51±0.067) 5
EL 1.61-1.93 (1.77±0.061) 5
EW 1.40-1.66 (1.54±0.051) 5
ProW 0.83-0.94 (0.88±0.021) 5
ProL 0.57-0.42 (0.48±0.028) 4
PyL 0.73-0.57 (0.64±0.023) 5
PTL 1.01-0.88 (0.96±0.025) 4
MSTL 0.83-0.78 (0.79±0.011) 4
MTTL 0.96-0.78 (0.88±0.033) 4
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Prosternal lobe (Fig. 43F) transverse and narrow, its anterior margin densely with hair. Prosternal keel completely with two carinal striae, of which the basal ends are united with each other in an arch; surface of keel evenly punctate as basal half of head.
Mesosternum longitudinally and shallowly sulcate on median third; lateral third evenly punctate as basal half of head and extremely finely strigate; sometimes lateral marginal stria present on basal half at each anterior corner. Meso-metasternal suture well impressed and complete. Metasternum longitudinally and shallowly sulcate on mid line; lateral metasternal striae strongly carinate and divergent posteriorly. Intercoxal disk of metasternum sparsely and coarsely punctate, the punctures twice as coarse as mesosternal punctures, and other fine ones sparsely intermingled among them. Lateral disk sparsely covered with large punctures, the punctures becoming finer apically.
Intercoxal disk of 1st abdominal sternum deeply striate on basal three-fourths on each lateral side, and punctate as intercoxal disk of metasternum, but the punctation is much denser.
Protibia slender and with two denticles on outer margin.
Male genitalia as shown in Fig. 44.
Remarks. Niponius impressicollis is the largest species of the genus in Japan. It can easily be recognized by its size and the presence of excavations on the pronotum.
This species is found from the galleries of a scolid beetle, Hylesinus
striatus Egg. on ash, Fraxinus mandchuria (Kryzhanovskij and Reichardt,
1976).
Ohara (1994)
[Honshû] <Fukushima-ken> 2 exs., Yunohana, Tateiwa V. Minami-Aizu, 19/vi/1947, Y. Kurosawa leg.; 4 exs., Onozawa, Egawa, Minami-Aizu, 17/vi/1950, Y. Kurosawa leg. (NSMT). <Mie-ken> 2 exs., Mimune, 18-21/vi/1955, H. Ôhira leg. <Hiroshima-ken> 2ÅâÅâ, Sandankyô, Aki, 7-8/viii/1966, S. Ôsawa leg.
[Honsho] Fukushima-ken: Douzan (1 ex., 2/viii/1972), K. Tazoe. Gumma-ken: Yunogoya-rindô, Minakami (1 ex., 7/viii/1988), K. Akiyama. Kanagawa-ken: Sagami-Oyama, alt. 900-1200 m (1 ex., 15/vi/1994), K. Kawada.
