Promalactis arcicosta Wang, 2021

Wang, Shuxia & Liu, Chen, 2021, Taxonomic study of the genus Promalactis Meyrick, 1908 (Lepidoptera: Oecophoridae) X. The commotica species-group, with descriptions of twenty-two new species, Zootaxa 4980 (2), pp. 293-330 : 296-297

Promalactis arcicosta Wang , sp. nov.

( Figs 3 , 25 , 45 )

Type material. CHINA, Tibet: Holotype ♂ , Tongmai Town (30.10°N, 95.08°E), Bomi County, 2029 m, 14.VIII.2018, leg. MJ Qi, slide No. LC 19413 . Paratypes: 2♀, 13.VIII.2018, other data same as holotype, slide No. LC 19600 ; 9♂ 4♀, Tongmai Town , Bomi County, 1997‒2029 m, 23‒24. VI.2019, leg. MJ Qi & JQ Deng, slide Nos. LC 19399 ♂, LC19394 ♀.

Diagnosis. The new species can be distinguished from other species of the group by the male genitalia with asymmetrical valvae widened from beyond the middle to before the apex, and the symmetrical sacculus that is beak-shaped distally; and in the female genitalia by the heavily sclerotized posterior half of the ductus bursae with 14‒20 spines.

Description. Adult ( Fig. 3 ). Forewing length 5.5‒6.5 mm.

Head: Vertex cream white, frons greyish brown, occiput rust brown. Labial palpus with second palpomere rust brown on outer surface, orange yellow on inner surface; third palpomere black except white apically. Antenna with scape greyish white on ventral surface, cream white except black apically on dorsal surface; flagellum black, with white annulation on dorsal surface.

Thorax: Dorsum of mesothorax and tegula rust brown. Forewing orange yellow to rust brown; markings white edged with black scales: costal spot large, sub-quadrangular, slightly narrowed posteriorly, reaching anterior angle of cell; basal streak oblique inward to base of fold; antemedian streak from dorsal 1/2 extending to basal 1/3 of anterior margin of cell, slightly arched outward; dorsal streak short, much slender, from beyond basal 1/6 extending to tornal spot; tornal spot large, straightly reaching posterior angle of cell; apical spot ovate; terminal spot small, below apical spot; fringe orange yellow, except grey around tornus. Hindwing and fringe grey. Foreleg black, femur greyish white ventrally, tibia with a white spot at base and middle respectively, with a tuft of white scales at apex, tarsus white at apices of basal two tarsomeres; midleg greyish white ventrally, black dorsally, tibia with a white spot at base, with a tuft of white scales at apex, tarsus white at apices of basal two tarsomeres, apical one tarsomere white; hindleg brown ventrally, greyish black dorsally, tarsus white at apices of basal three tarsomeres, distal two tarsomeres white.

Abdomen: Male genitalia ( Fig. 25 ). Uncus campanulate, wide at base, narrowed to middle, thereafter abruptly narrowed to narrowly rounded apex. Gnathos longer than uncus; mesial plate narrow basally, slightly widened to rounded apex distally, with a small ovate membranous process near apex dorsally. Tegumen furcate from posterior 1/3; lateral arms narrowed to rounded apex. Valvae narrowed at base, broadened to preapex, asymmetrical: left valva narrower, costa narrow, arched, rounded at apex, with a tuft of dense long setae dorsoapically, with a spine dorsoventrally, right valva broader, costa widely banded, roundly arched medially, setose distally, with a short apical spine directed ventrad; sacculus broadly banded, basal 2/3 uniform, distal 1/4 produced to a free setose beak-shaped process bearing an apical spine directed dorsad. Saccus triangular, as long as gnathos, wide at base, narrowed to rounded apex. Juxta relatively short, with spine-shaped process posterolaterally. Aedeagus approximately 1.5 times length of right valva, straight, with two cornuti; one cornutus longer and wider, bent medially, with spur-like apex, the other cornutus shorter and smaller.

Female genitalia ( Fig. 45 ). Apophyses anteriores longer than half length of apophyses posteriores. Eighth sternum rectangular, concave semicirclely at middle on posterior margin, setose. Antrum funnel-like. Ductus bursae heavily sclerotized on posterior half, with several spines, membranous on anterior half, coiled. Corpus bursae membranous, ovate, approximately half length of ductus bursae, with two narrowly elongate signa, half length of corpus bursae, placed medially.

Distribution. China (Tibet).

Etymology. This epithet is derived from the Latin arci- and costa, referring to the conspicuously convex costa.

Figures

FIGURES 1‒8. Adults of Promalactis spp. 1, P. apiculifera, holotype, ♂; 2, P. apisetosa, holotype, ♂; 3, P. arcicosta, holotype, ♂; 4, P. baoshana, holotype, ♂; 5, P. bicornuta, holotype, ♂; 6, P. bilobignatha, paratype, ♂; 7, P. binipapillata, paratype, ♀; 8, P. bispina, paratype, ♀. Scales = 2 mm.

FIGURES 23‒28. Male genitalia of Promalactis spp. 23, P. apiculifera, holotype, slide No. HXM14207; 24, P. apisetosa, holotype, slide No. DZH11066; 25, P. arcicosta, paratype, slide No. LC19399; 26, P. baoshana, holotype, slide No. JYY17588; 27, P. bicornuta, holotype, slide No. DZH10246; 28, P. bilobignatha, paratype, slide No. LC19354, 28a, enlarged aedeagus. Scales = 0.2 mm.

FIGURES 45‒50. Female genitalia of Promalactis spp. 45, P. arcicosta, slide No. LC19394; 46, P. binipapillata, slide No. JYY17673; 47, P. bispina, slide No. JYY17838; 48, P. curvicosta, slide No. LC19762; 49, P. denticuligera, slide No. LC19313, 49a, enlarged ductus bursae, 49b, enlarged singum, slide No. JYY17327; 50, P. motuoensis, slide No. JYY17597. All paratypes. Scales = 0.2 mm.