Bucculatrix liubaensis Liao & Yagi & Kobayashi & Huang 2019, sp. nov.

Bucculatrix liubaensis Liao, Kobayashi & Huang, sp. nov.

Figs. 4, 6, 11–28

Diagnosis. Bucculatrix liubaensis is very similar to B. yingjingensis with differences given in the diagnosis of the latter above. Additionally, it can be distinguished from other species by its somewhat bicolored forewing pattern, with a straight transverse white line and two small circular white spots. The forewing pattern and female genitalia are similar to those of B. noltei Petry, a European Artemisia -feeding species, but B. noltei lacks the transverse white line of the forewing and has a pair of wider and loosely curved furrows on segment VIII in the female genitalia (Bengtsson & Johansson 2011: 63).

Description. Female (Figs. 4, 6, 11–16). Wing expanse 7.8–8.0 mm. Head. Face smooth, with cream white scales (Figs. 4, 11, 13). Vertex with slender, hair-like, reddish brown scales, projected in all directions medially, and covered with some appressed large, yellowish to reddish scales all around (Figs. 11, 12). Antennae filiform, nearly 3/4 of forewing length; scape stout, forming eye-cap, densely covered by yellowish to reddish scales, with some long hair-like scales projected anteriorly and laterally; pedicel short, yellowish; flagellum dark mixed with some brownish scales, first flagellomere distinctly twice as long as other flagellomeres (Figs. 4, 11). Proboscis without scales, short, smooth, with about 7 pairs of styloconic sensillae on apical half laterally (Figs. 12, 14, 15). Labial palpus very short, one segmented, inconspicuous, apex reaching to about base of proboscis (Fig. 16).

Thorax. Thoracic tergites covered with dark brownish or black scales. Foreleg with brownish and black scales mixed, epiphysis arising near tip of foretibia; midleg with color pattern very similar to that of foreleg, with one pair of asymmetrical apical spurs; hindleg yellowish to brown with some black scales on tarsus, and elongate hair-like scales on tibia, with two pairs of asymmetrical spurs (Figs. 17, 18). Forewing length about 3.7 mm, lanceolate, somewhat bicolored, yellow to brownish basally and black apically, separated by a narrow creamy white line near basal 1/3 with a black spot posteriorly on the fascia, 2/3 of apex with two small cream white spots at anterior and posterior margin; fringes and ventral surface brown to dark brown (Fig. 4). Venation (n = 1) with Sc broadened basally, ending basal to 1/3 of wing margin; R with five branches, both of basal half and a small apical part of R 1 absent, stalk between R 1 and Rs almost absent, R 3 almost free, R 5 stalked with M 1; M 2, CuA and CuP poorly differentiated, CuP as a distinct fold; 1A+2A well developed, reaching to about midpoint of posterior margin (Fig. 6). Hindwing dorsal and ventral surfaces and fringes dark brown to black, with two frenular bristles (Fig. 4). Venation with Sc broadened basally, apex nearly extending to 4/5 of hindwing; Rs not reaching wing apex; M 1 and M 2 weakly developed and well separated; CuA well developed, ending near midpoint of wing margin; A as a fold, with apex absent (Fig. 6).

Abdomen. Dorsally black and ventrally dark brown except abdominal apex with elongate yellow scales (Fig. 4). Genitalia (n = 2) with papillae analis moderately long, well sclerotized, sparsely covered with long hair-like setae on tapering apex (Figs. 19–21); apophyses posteriores rather long and formed by extensions of segment IX, well sclerotized, with slightly broadened at base (Fig. 19). Eighth abdominal segment longer than papillae analis, weakly sclerotized, forming a pair of depressed inwards and folded furrows laterally, with a group of specialized slender scales on each side; apophyses anteriores absent (Fig. 20). Ostium bursae cup-shaped; antrum (i.e., sclerotized portion of ductus bursae) tubular, anterior half slightly curved; ductus bursae narrow, slender, membranous throughout; corpus bursae ellipsoidal, with signum formed by many rows of small, sclerotized, spine-like structures from caudal 1/6 to 2/5 (Figs. 19, 20, 23, 24). Ductus seminalis slender, arising from the middle part at base of corpus bursae, the same as ductus bursae (Figs. 19, 22).

Male. Unknown.

Holotype: ♀, China: Shizigou pasture, Yingpan Village, Liuba County, Hanzhong City, Shaanxi Province, 11.VIII.2018, daytime collected, leg. C. Q. Liao & G. H. Huang (specimen no. HAUHL 0177559, deposited in HUNAU).

Paratypes: 3♀, same data as holotype (specimen no. HAUHL 017557, 558, 560 –DNA no. LCQ060, deposited in HUNAU).

Host plant. Unknown.

Distribution. China (Shaanxi).

Etymology. The specific epithet refers to the type locality Liuba County.

Remarks. The adults were collected from a small plant community which mainly included some Asteraceae species from Shizigou pasture about 4 to 5 p. m. (Figs. 25–26). When we discovered them, they were resting motionlessly on the leaves of Artemisia sp. with antennae along lateral margins of the body (Figs. 27–28). We could not find larval feeding sign, cocoonet, cocoon on leaves and stems. The host plant is unknown but maybe Artemisia sp. (Asteraceae) because of the female adults found only on it.