Adults. Female (Figs 1, 2). Body oblong ovate, length 10.2 – 14.3 mm, width at maximum level of elytra 2.5 – 3.5 mm (n = 9), black, except epistoma, apical surface of maxillary palpi and four bands on each elytron yellowish-white, first two antennomeres dark brown and dorsal apices of them yellowish-white. Body covered with fine pubescence, colour paler on part of head, pronotum, femur, tibia, elytral bands and apical 1/6 of elytra. Head (Fig. 2a) small, finely punctured. Maxillary palpi long, subcylindrical, second segment longest, slightly thickened apically, third short, obliquely obconical, fourth obliquely truncated. Frons raised, nearly square, sides slightly concave at antennal insertions. Eyes large, elongate oval, weakly emarginate behind antennal insertions. Antennae (Fig. 2c) short and slender, generally reach base of pronotum, first antennomere longer than second, third longer than second, fourth the longest, gradually shortened from fifth to tenth, each antennomere of third to tenth weakly dilated apically, eleventh pointed apically, longer than tenth, ratios of antennomeres about 1:0.7:1.3:1.6:1.4:1.2:1.1:1.1:1.0:0.9:1.3. Pronotum subtrapezoidal, finely punctured, anterior margin nearly straight, rounded at sides, narrower than base, basal margin widely bisinuate, disc moderately convex at apical 2/3, weakly depressed in middle of each half of basal 1/3 (Fig. 1a, Fig. 2b). Scutellum tongue-shaped, rounded apically and concave in middle. Elytra slightly wider than pronotum, about 3.1 times as long as wide, parallel-sided from base to apical 1/4, then gradually narrowed apically. First elytral band short, transverse, oval or rectangle-shaped with rounded edges, in middle of basal 1/7 of each elytron; second band at outer half at basal 1/4 of elytron, transverse, sometimes nearly caret-shaped or slightly oblique backwards; third band in middle of elytron, transverse, nearly reaching suture, thickening quickly and rounded at inner end; fourth band at apical 1/4 of elytron, oblique at inner 2/3 or transverse. Though length and shape of four elytral bands variable among individuals, i.e. length of second band, width of third band and curveness of fourth band, these four bands are well separated, none of them connected to any other band (Fig. 1a, c and d). Pale pubescence at apical 1/7 of elytra, not dense as elytral bands, not reaching fourth elytral band. Ventral side sparsely and finely punctured. Median portion of prosternum short. Median portion of apical mesosternum with sparse granules and a median ridge (Fig. 1b, i), pointed apically. Mesosternal process long and acute, but not dividing mesocoxae completely. Posterior half of metasternum with a groove, apical of median metasternum projected and pointed on both sides of the groove (Fig. 1b, ii). Abdomen sparsely and finely punctured, 5^th sternite slightly concave in middle at apex.

Figure 1.  

Habitus of Stenoxylita quadrifasciata sp. nov. females, a. dorsal view; b. ventral view; c. dorsolateral view of body; d. variation of elytral bands. (a, b, scale bar, 5 mm, c, d, not to scale).

Figure 2.  

Habitus of Stenoxylita quadrifasciata sp. nov. female, a. head, front view; b. pronotum, dorsal view; c. antennae, left, dorsal view; (scale bars, 1 mm).

Female genitalia. Sternite VIII and tergite VIII longer than wide, with sparse long setae mixed with several short setae apically (Fig. 3a, b), apex of sternite VIII broadly rounded, slightly concave in middle (Fig. 3a), apex of tergite VIII broadly rounded (Fig. 3b). Ovipositor slightly constricted in middle, apical half spear-shaped, basal half gradually widening toward base, width at base wider than maximum width of apical half (Fig. 3c).

Figure 3.  

Female genitalia of Stenoxylita quadrifasciata sp. nov. a, b. Abdominal segment VIII and spiculum ventrale; c. ovipositor (a, c. ventral view; b. dorsal view; scale bar, 0.5 mm).

Male unknown. Based on characters of its congeners and other melandryids, males may present only small morphological differences from females, except the dilated basal three tarsomeres of front tarsi.

Stenoxylita quadrifasciata sp. nov. differs from its congeners, Stenoxylita trialbofasciata (Hayashi & Katö, 1956) and Stenoxylita sasajii Toyoshima, 2001, in terms of the number and pattern of elytral bands. As indicated by their specific names, the new species exhibits four bands on each elytron, whereas S. trialbofasciata only has three bands on each elytron. Basal half of pronotum and scutellum of S. trialbofasciata are dark red, whereas pronotum and scutellum are black in Stenoxylita quadrifasciata sp. nov. In S. sasajii, the first elytral band is arcuate, with the sutural end reaching the scutellum, whereas in Stenoxylita quadrifasciata sp. nov., it is short and transverse, located away from the scutellum. Additionally, the second band in S. sasajii bends obliquely backwards and reaches the third band near the inner end of the third band, while, in S. quadrifasciata sp. nov., the second band is short and transverse at the outer half of elytron, not extending backwards nor reaching the third band in any of availabe nine specimens (Fig. 1a, c and d).

The specific name of this species refers to the four pale bands on each elytron.