Dactylolabis (Dactylolabis) gracilistylus Alexander, 1926

Figs 1-3, 4-7

Dactylolabis gracilistylus Alexander, 1926: 372. Type locality: China: Zhejiang.

Diagnosis.

Wing yellowish hyaline, pterostigma brownish. Vein R3 as long as vein R2+3. Veins R4 and R5 relatively straight. Vein M1 as long as vein M1+2. Crossvein m-cu located before or near base of cell dm. Posterior margin of 9t with an M-shaped process and a shallow V-shaped notch at middle. Inner gonostylus slender, curved; gonocoxite very elongate and slender, more than twice as long as outer gonostylus. Aedeagus very big, with a shallow V-shaped notch at posterior margin.

Redescription.

Male (n = 3). Body length 8.2-8.5 mm, wing length 8.4-8.8 mm, antenna length 1.6-1.7 mm.

Head (Figs 1, 2) dark brown with pale gray pollen. Vertex with long setae. Rostrum and palpus brown. Antenna brown.

Thorax (Figs 1, 2) mostly dark brown with gray pollen. Pronotum rather long; mesonotum brownish, prescutum dark brown with pale gray pollen. Thoracic pleuron mostly dark brown with dense gray pollen. Legs: coxae brown with gray pollen; trochanters brownish-yellow; femora more yellow at base, brownish-yellow at tip; tibiae brownish-yellow; tarsi brown. Wing (Figs 1, 3) yellowish hyaline, pterostigma more brownish; veins brownish. Venation: Rs long; R2 relatively oblique; R3 as long as R2+3; R4 and R5 relatively straight; M1 as long as M1+2; m-cu located before or near base of cell dm. Halter (Fig. 1) length approximately 1.3 mm, halter stem yellowish; halter brownish.

Abdomen (Fig. 1) elongated, tergites brownish-yellow, sternites dark brown.

Hypopygium (Figs 1, 4-7) dark brown with brownish setae. Surface of 9t with plenty of long setae, posterior margin with an M-shaped process, medially with a shallow V-shaped notch; posterior margin of 9s with plenty of long setae; outer gonostylus cylindrical; inner gonostylus slender, curved; gonocoxite very elongate and slender, more than twice as long as outer gonostylus; aedeagus hyaline, very big, posterior margin with a shallow V-shaped notch.

Female. Similar to male (Alexander 1926: 372).

Material examined.

1 male (CAU), China: Zhejiang, Yuyao, Siming Mountain, 1980.IV.27 , Jikun Yang. 1 male (CAU), China: Zhejiang, Qingyuan, Baishanzu, 1984.IV.19 , Hong Wu. 1 male (CAU), China: Zhejiang, Deqing, Mogan Mountain, 1991.IV.20.

Distribution.

China (Zhejiang).