Bucculatrix nigerivalva, Liu & Liu, 2022

Liu, Hongxia & Liu, Tengteng, 2022, Two new species of Bucculatrix Zeller from southeast China (Lepidoptera: Bucculatricidae), Zootaxa 5100 (1), pp. 137-144 : 140-143

Bucculatrix nigerivalva sp. n.

DZNJẇfl [Chinese name]

Figures 3, 3a , 9–12

Diagnosis. The new species is closely related to B. crataega and the North American B. pomifoliella on the male genitalia. From B. crataega , the new species can be separated by: i) the strongly sclerotized and black distal part of the valva, ii) the furcated cornutus and iii) the almost semicircular vinculum; in B. crataega , the distal part of the valva is not as such strongly sclerotized and black ( Fig. 7 ), the cornutus is composed of a series of micro spines ( Fig. 8 ) and the vinculum is triangular on anterior margin ( Fig. 7 ). From B. pomifoliella , the new species can be distinguished by: i) the cornutus composing of a series of micro spines and ii) the triangular vinculum ( Braun 1963: 175, Fig. 228).

Type material. Holotype, ♂, CHINA, Zhejiang province, Tianmu Mt. , 30°20.27′N, 119°24.34′E, 700 m, 2018. vi.15, leg. Tengteng Liu, registration SDNU. Ent 000236 (genitalia and DNA barcode no. SDNU.LIU0156).

Adult ( Fig. 3 ). Forewing length 2.5 mm. Face and frons white, scale tuft on vertex white, mixed with orange in central. Labial palpus minute and white. Antenna with eye cap white, posterior half with brown scales dorsally, first flagellomere notched in male ( Fig. 3a ); flagellum blackish gray dorsally, 4 th to 7 th and 10 th to 13 th units counted from apex black dorsally. Legs yellowish white, black on outer surface of tibiae, with dense long yellow piliform scales on hind tibiae. Forewing ground color white, two golden costal streaks at basal 2/5 and 3/5, with scattered black scales near costa, outwards obliquely, jointed at apex of cell, the outer streak continue extending to tornus; a golden stripe along fold, below with a black dot at distal 2/5; a black dot above tornus; apical area golden; cilia grayish white, black distally around apex. Hind wing and cilia yellowish gray. Abdomen yellowish gray dorsally, yellowish white ventrally.

Male genitalia ( Figs 9–12 ). Socii developed, about 1/3 length of tegumen, with sparse long setae ( Fig. 10 ). Tegumen sclerotized on lateral margin, straight on posterior margin. Valvae not fused with each other, heavily sclerotized towards apex, black on distal part; bifurcated distally, ventral branch curved inwards distinctively, rounded apically, dorsal branch slightly curved inwards, narrowed towards apex, bluntly pointed apically. Vinculum almost semicircular, more sclerotized and slightly protruded anteriorly. Phallus about 2.5 times as long as length of valva + vinculum, basal 1/3 arched, median 1/3 straight, then curved by 150°, distal 1/3 straight; basal 2/3 spindle-shaped together with membranous phallobase; cornutus a sclerotized spine, about 1/7 length of phallus, unequally bifurcated and curved distally. Scale-sac broad and rounded ( Fig. 12 ).

Distribution. China (Zhejiang). Only known from the type locality.

Etymology. The specific name is derived from the Latin adjective “ niger ” and “ valva ”, indicating the black distal part of the valva in the male genitalia.

Remarks. This species is associated with B. bechsteinella group in the sense of Baryshnikova (2008) and is closest to B. pomifoliella on the basis of morphological characters. However, the genetic uncorrected distance between B. nigerivalva and B. pomifoliella is the largest among the species group ( Table 2 ).

Figures

FIGURES 2−3. Adult of Bucculatrix spp. 2, 2a, B. coadnata sp. n., holotype, registration SDNU.Ent000428. 3, 3a, B. nigerivalva sp. n., holotype, registration SDNU.Ent000236. Scale bar for Figs 2 and 3: 2 mm, for Figs 2a and 3a: 0.2 mm.

FIGURES 9−12. Male genitalia of Bucculatrix nigerivalva sp. n. 9−10, genitalia excluding phallus: 9, ventral view; 10, dorsal view, arrow indicating socii; 11, phallus; 12, scale-sac, slide no. SDNU.LIU0156. Scale bar for Figs 9−11: 0.1 mm, scale for Fig. 12: 0.2 mm.

FIGURES 4−8. Male genitalia of Bucculatrix spp. 4−6, B. coadnata sp. n., holotype, slide no. SDNU.LIU0155; 4, genitalia excluding tegumen (ventral view); 5, tegumen (ventral view); 6, scale-sac. 7−8, B. crataega, holotype, SDNU.LIU0024; 7, genitalia excluding phallus (ventral view); 8, phallus. Scale bar for Figs 4, 5, 7, 8: 0.1 mm, for Fig. 6: 0.2 mm.