Matileola yangi
Male. All body, including abdominal tergites dark.
Head. Male frons linear, facettes comparatively large, round, microtrichia between minute but distinct. Two large lateral ocelli. Antenna all dark.
Thorax. Mesonotal microtrichia short: a sagittal acrostichal and 2 dorsocentral rows are distinct. Only supra-alar and postalar setae of thorax are stronger. Scutellum short, with short pale hairs.
Legs without stronger setae on legs but femoral and tibial microtrichia are comparatively long and less numerous than in Lygistorrhina spp. (e.g., fore tibia with 8 rows only, probably also mid tibia with 8 rows). Microtrichia are ordered in rows, which are less regular than in Lygistorrhina. Fore and mid tarsi are thin. No tibial spur on fore tibia, mid tibia with only 1 thin spur. Hind tibia baseball-bat shaped.
Wing uniformly brown, not spotted, costal and radial veins light brown, other veins ochre. Vein R1 reaches 0.625 of wing. Costal vein is extremely thick from its conjointment with R1 to its apex. Costa ends at 2/3 of distance of R5 and M1. Cu1 curved arched; Cu2 straight, parallel to Cu1, and continued to the curve in Cu1. A1 close to and nearly parallel with hind wing margin. Halter light yellow, actually longer since knob deformed in our specimen.
Abdomen very thin and much longer than wing, tergites all dark. Tergite 8 comparatively long with a large medio-caudal process. This process may be slightly different from that one on our figure (the process is half of a cone, i.e. may be depressed at a different extent), but microtrichia cover all part, in contrast to M. similis. Sternite 8 as in M. similis. Tergite 9 broad and slightly longer than gonocoxites, its macrosetae slightly longer, than in M. similis. Gonostylus shorter than gonocoxite, its apical tooth comparatively short, broad and rounded. Gonocoxites without any conspicuous armature, but with a twice, angularly bent narrow medial process. The pair of medial processes (placed most dorsal under T9), and ventral wall of gonocoxites form a "tunnel", in which aedeagal complex moves forward and backward along the body axis. Aedeagus mostly membranous and protected by a scutiform "shield" (I would rather not decide on its morphological - homology - status). Aedeagal apodeme small, joins ventral wall of the "shield".
Female unknown. (after Papp, 2002, 2005)
Antenna 0.35 mm, scutellum 0.07 mm. Fore tibia 0.525 mm long, fore metatarsus 0.475 mm. Mid tibial spur 0.038 mm. Hind tibia 1.29 mm, hind metatarsus 0.725 mm long, breath 0.13 mm. Hind tibia medial spur 0.225 mm, lateral spur - 0.10 mm. Wing length (measured) 0.45 mm