Macrobathra basilutea Lu, Liang & Hsu, 2025 sp. nov. (Figs. 3, 4, 6, 7, 10, 11, 16, 17)

Type material. Holotype: 1♂, TAIWAN: Taichung City, Heping, Wushikeng Research Center, 850m, 27. IV. 2024, Y. Y. Lu, Y. M. Hsu & J. Y. Liang Coll. (NMNS). Paratypes: 2♀, TAIWAN: Nantou Co., Renai, Huisun forest station, 780m, 9. XII. 2023, Y. Y. Lu & J. Y. Liang Coll. (JY295) (NMNS); 1♀, TAIWAN: Nantou Co., Renai, Huisun forest station, 500m, 10. XII. 2023, Y. Y. Lu & J. Y. Liang Coll. (NMNS); 2♀, TAIWAN: Hualien Co., Xiulin, Lushui, 410m, 26. X. 2021, Y. Y. Lu & Z. L. Chen Coll. (Gen. Prep. YYLU-290); 1♂ 1♀, same locality, 6. XII. 2021, Y. Y. Lu, Z. L. Chen & K. Y. Chen Coll. (JY299) (NMNS); 1♂, TAIWAN: Hualien Co., Xiulin, Huoran Pavilion, 1000m, 28. VII. 2019, Y. Y. Lu, Y. T. Chang, Y. C. Lin & R. J. Lin Coll. (Gen. Prep. YYL0032) (JY294) (NMNS).

Description. Male (Figs. 3, 6): Antennal length 2.7 – 3.7 mm (n = 3), forewing length 4.2 – 4.9 mm (n = 3). Head: Antenna light yellow, scape dark brown, flagellum scattered with some dark brown scales at basal and distal third; labial palpus elongated and upcurved, second palpomere slender, dark brown scales mixed with light yellow scales, third palpomere nearly as long as second palpomere, dark brown, with a white longitudinal line ventrally; vertex and frons smooth-scaled, metallic brown. Thorax: Surface and tegula dark brown. Legs: Foreleg dark brown, fore tarsus scattered with light yellow scales medially and apically; midleg dark brown, mid tibia ringed with light yellow scales apically, with a pair of apical spurs, with inner longer than outer, mid tarsus alternating with a ring of light yellow scales and a ring of dark brown scales; hindleg dark brown, hind tibia with a large patch of light yellow scales medially, ringed with light yellow scales apically, with a pair of medial spurs and a pair of apical spurs, both with inner longer than outer, hind tarsus ringed with light yellow scales medially and apically. Abdomen: surface dark brown, basal dorsum covered with a patch of light yellow to brown scales; a pair of pale brown tufts present at caudal end. Forewing: Moderately elongate and lanceolate in shape; ground color dark brown; median yellow fascia broad, running across basal 1/8 to slightly over half of forewing, nearly rectangular; fringes color similar to ground color. Hindwing: Ground color and fringes color dark brown; vannal tuft a bundle of slender blonde hairs present along base of vein 2A.

Female (Figs. 4, 7): Antennal length 3.2 – 3.9 mm (n = 7), forewing length 4.7 – 5.3 mm (n = 7). Most characters are similar to the males, except for the broader basal dark brown patch on the forewing, and the vannal tuft presented along base of vein 2A of the hindwing, which is a bundle of long dark grey hairs.

Male genitalia (Figs. 10, 11): Brachia of uncus slender, sinuate toward apex; tegumen broad; vinculum bandshaped, somewhat broad medially, concaved at medial dorsum; two valvae minute, small protrusions basally, slightly setose; valvellae asymmetric, left valvella broad basally, contracted in middle third, distal third enlarged with a truncated apex, right valvella broad basal half, slightly tapering toward apex at distal half, apex also truncated; anellus slender, with a triangular process distally, scarcely setose; aedeagus stout, straight and short, two forms of cornuti present, one with rod-liked and wrinkled sclerites, the one with a short and stout spine basally, rows of spines on distal half, longer toward distal end.

Female genitalia (Figs. 16, 17): Length of apophyses anteriores about 3/5 length of apophyses posteriores; seventh sternite with a broad pocket near sterigma with many bristles inside; sterigma sclerotized; ductus bursae with an accessory bursae emitted from posterior 1/4; corpus bursae oval, with a pair of ridged signa slightly different in size.

Diagnosis. The wing pattern of the new species is similar to that of M. terniprocessa Li, 2023, but they can be distinguished by the shape of the yellow fascia of M. basilutea sp. nov. nearly rectangular whereas that of M. terniprocessa trapezoidal, and the proportion of yellow fascia on the entire forewing of M. basilutea sp. nov. just over half while that of M. terniprocessa about 1/3. In the male genitalia, this new species can be easily identified by its distinctly minute valvae and the triangular process of the anellus. In the female genitalia, it can be recognized by its ridge-like signa.

Etymology. The name is a combination of two Latin words “ basi ” and “ lutea ”, referring to its basal yellow patch on the dorsal abdomen in the male adult.

Distribution. Taiwan (Taichung, Nantou and Hualien).