Promalactis varilonga Wang, 2024

Wang, Shuxia, Liu, Chen & David, Lees, 2024, Partial revision of Promalactis Meyrick (Lepidoptera: Oecophoridae), based on specimens deposited in the Natural History Museum, London, Zootaxa 5536 (1), pp. 1-58 : 32-42

Promalactis varilonga Wang , sp. nov.

( Figs 33 , 66 )

Type material. Brunei: Holotype ♂, Bukit Pagon LP 308 , upper montane forest, 5520 m, 15–20.II.1982, leg. G.S. Robinson, slide No. NHMUK010316989 .

Paratype. 1♂, same data as holotype, slide No. NHMUK010317162 .

Diagnosis. The new species is similar to P. arcicosta Wang, 2021 in having an asymmetrical valva widened to before bilobed apex in the male genitalia. It can be distinguished by the distinct dorsal streak and the absence of the tornal spot of the forewing; in the male genitalia by the uncus bifurcate distally, the mesial plate of the gnathos strongly hooked, and the phallus with one cornutus. In P. arcicosta , the uncus is not furcated, the distal plate of the gnathos is sub-lingulate, and the phallus has two cornuti.

Description. Adult ( Fig. 33 ). Forewing length 5.0– 5.5 mm.

Head. Vertex snowy white, frons grey, occiput rust brown. Labial palpus with second segment rust brown, covered with black scales on outer surface, pale brown on inner surface; third segment black except white at base and apex. Antennal scape snowy white dorsally, grey ventrally; flagellum black, annulated with white on dorsal surface.

Thorax. Mesonotum and tegula rust brown, mesonotum with a white horizontal band posteriorly, edged with black scales. Forewing ochreous brown, costal margin with black scales scattered from base to apex, with a white dot at base; markings white edged with black scales: costal spot large, extending from distal 1/3 to above posterior angle of cell; basal streak from dorsum oblique inward to above base of fold; antemedian streak from basal 3/5 of dorsum oblique inward to basal 1/5 below costal margin, widened anteriorly; dorsal streak from before tornus narrowed obliquely outward to posterior margin of cell; tornus with diffused black scales; apical spot ovate; fringe orange yellow except grey between costal and apical spots, white on extension of apical spot. Hindwing and fringe grey. Foreleg black except femur brown ventrally, tibia with white dot at base and middle, with a tuft of white scales at apex, tarsus white at apices of basal two tarsomeres; midleg grey 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 and on entire apical tarsomere; hindleg yellowish brown ventrally, black dorsally, tarsus white at apices of basal four tarsomeres and on entire apical tarsomere.

Male genitalia ( Fig. 66 ). Uncus wide at base, slightly narrowed to basal 1/3, parallel sided medially, distal 1/3 U-shaped, each lateral lobe spine-shaped; ventral surface distinctly bulged near posterior margin, with a rectangular process. Gnathos about same length as uncus; mesial plate strongly hooked, narrowed to rounded apex; basal arm band-like, about same length as mesial plate. Tegumen with a broad triangular anterior emargination. Valva narrow at base, widened to before bilobed apex; asymmetrical: Left valva with dorsal lobe short, tubular, finely serrate on dorsal margin, with a cluster of strong setae apically, ventral lobe narrow triangular, pointed at apex, with dense setae distally, 2 times length of dorsal lobe; costa with a sclerotized band narrowed to base of dorsal lobe; sacculus wide at base, narrowed to basal 2/3, then slender and setose to base of ventral lobe. Right valva with apical lobes shorter than those of left valva; dorsal lobe short, papillary, with a tuft of long setae apically, ventral lobe triangular, about 3 times length of dorsal lobe, setose; sacculus slightly narrowed and setose distally. Saccus triangular, shorter than uncus. Juxta slightly widened from base, with three distal lobes: left lobe weakly sclerotized, slightly wide at base, narrowed to pointed apex; median lobe heavily sclerotized, slightly shorter than left lobe, spine-shaped; right lobe longest, approx. same length as costa of right valva, heavily sclerotized. Phallus slightly shorter than left valva, tubular basally, tapered distally; cornutus being a small spine, placed at distal 1/3.

Female unknown.

Distribution. Brunei.

Etymology. The specific epithet is derived from the Latin vari- and longus, referring to the juxta with three distal lobes of different lengths.

Figures

FIGURES 30–33. Adults of Promalactis spp. 30. P. spinellosa sp. nov.; 31. P. subfalcata sp. nov.; 32. P. trispinata sp. nov.; 33. P. varilonga sp. nov. 30–32: Males and holotypes; 33: Male and paratype. Scale bar = 1.0 mm.

FIGURES 64–66. Male genitalia of Promalactis spp. 64. P. subfalcata sp. nov.; 65. P. trispina sp. nov.; 66. P. varilonga sp. nov. All holotypes. Scale bar = 0.2 mm.