NEOSTETHYNIUM Ogloblin, 1964

(Figs 659–676)

Stethynium (Neostethynium) Ogloblin, 1964: 106 . Type species: Stethynium (Neostethynium) stenopterum Ogloblin, 1964, by original designation. Raised to genus by Huber, 1987: 827 and Yoshimoto, 1990: 45.

Diagnosis. Head in lateral view with vertex almost horizontal and forming a right angle with posterior surface of head (Fig. 659); face with faint subantennal sulci (Fig. 660); clava 3-segmented, the segments separated by transverse sutures (Figs 659, 665); mandibles small, their apices not touching when closed (Figs 660, 661); ocelli forming an equilateral triangle (Fig. 663a); scutellum with 1 posterolateral seta and with campaniform sensilla abutting (Fig. 666); frenum entire (Fig. 666); genitalia at base with a dark reddish colour (Figs 669, 671). Male mandibles large, crossing when closed, each with 2 equal ventral teeth and a dorsal serrate apically rounded tooth (Fig. 672, 673).

Discussion. Neostethynium is one of three Nearctic genera with clava 3-segmented. It differs from Krokella by having fore wing narrow, venation shorter than half length of wing, and frenum entire. It differs from Stethynium by the mandibles; in Stethynium the mandibles in both sexes have 4 equal teeth.

Important reference. Ogloblin (1964).