Genus Hylomesa Krombein, 1968

Hylomesa Krombein, 1968: 3–7 . Type species: Myzine tricolor Smith, 1858, by original designation of Krombein, 1968, Proc. Nati. Muse. 124: 3.

Notes. The genus Hylomesa contains 10 species and one subspecies worldwide, among these eight species and one subspecies are distributed in the Oriental Region, one in the Afrotropical Region and one in the Palearctic Region. One species was recorded from China by Tsuneki (1986). In this study, four species were collected, including one new species and two new records.

Diagnosis. Female. Head more or less square (Figs 3, 10, 18, 28) in dorsal view; mandible (Figs 2, 17) with a stout subapical tooth on inner margin; clypeus (Figs 2, 17) with weak to strong median carina; occipital carina complete dorsally; mesosoma (Fig. 1) considerably longer than wide; pronotum (Figs 4, 11, 19, 29) comparatively longer than in Mesa, sometimes apically with strongly transverse carina; anterior surface of mesopleuron (Figs 5, 20) more or less concave; propodeum (Figs 6, 12, 22, 31) with a median cuneate groove; T1 (Figs 7, 14, 23, 33) usually with strongly transverse carina; T6 (Figs 8, 15, 24, 35) with dense to sparse punctures and not longitudinally striate as in Mesa .

Male. Head (Fig. 26) not square as in female; clypeus almost same as in female, but median carina weaker; pronotum (Fig. 30) anteriorly strongly carinate; mesopleuron without anterior carina and not produced anteriorly in middle; propodeum (Fig. 32) with carina between dorsal and posterior surfaces; T1 (Fig. 34) anteriorly weakly to strongly carinate; inner margin of hind coxa carinate; length of S7 0.4–0.5× less than length of the T7 (Fig. 36) in lateral view.