Mesoleptidea, Viereck, 1912

Li, Tao, Li, Bin & Sun, Shu-Ping, 2024, Three new species of Mesoleptidea Viereck (Hymenoptera, Ichneumonidae) from China, Zootaxa 5397 (2), pp. 251-263 : 252

Key to the species of Mesoleptidea known from China and the Eastern Palaearctic region

1. Fore wing without areolet. Mesosoma with large red flecks. Hind coxa red. Face white. Pronotum reddish yellow with black flecks. Mesoscutum, scutellum and propodeum predominantly red................... M. cingulatus (Gravenhorst, 1829)

-. Fore wing with areolet present. Mesosoma black with white or yellow flecks. Hind coxa black, or with black flecks. Mesoscutum, scutellum and propodeum not predominantly red............................................................ 2

2. Apical margin of clypeus convex forward. Tergites 3–5 red........................ M. prosoleucus (Gravenhorst, 1829)

-. Apical margin of clypeus truncate or almost so. At least tergite 2 black, posterior margins more less white............... 3

3. Face black. Mesosoma without red brown flecks. Posterior portion of scutellum yellow. Hind coxa and femur red to red brown. Posterior portions of tergites 3–5 white or with white spots................................ M. stalii (Holmgren, 1858)

-. Face white or brown. Mesosoma with brown spots. Scutellum entirely black or darkish brown. Hind coxa black or darkish brown. Tergites black, lateral margins of tergites 3–6 white.................................................... 4

4. Ovipositor sheath narrowed posteriorly ( Fig. 14 ). Mesosoma black or almost entirely black, with dense punctures ( Figs 5 , 19 ). Hind coxa black...................................................................................... 5

-. Ovipositor sheath parallel or almost so, not narrowed posteriorly ( Fig. 41 ). Mesoscutum, at least lateral lobe, brown; Mesostenum whitish yellow or red brown. Mesopleuron slightly shiny, with relatively sparse and indistinct punctures ( Fig. 32 ). Hind coxa red brown, or with large white spots...................................................................... 6

5. Clypeus with distinct punctures. Scutellum quadrate. Tergite 1 straight ( Fig. 25 ). Tergite 2 as long as posterior width ( Fig. 26 ). Tergite 3 shorter than its maximum width ( Fig. 26 )................................ M. nigricoxalis Li & Sun , sp. nov.

-. Clypeus almost shiny, with weak, indistinct punctures. Scutellum trapezoidal. Tergite 1 uniformly arched ( Fig. 12 ). Tergite 2 distinctly longer than posterior width. Tergite 3 longer than its maximum width................ M. nigra Li & Sun , sp.nov.

6. Mesopleuron almost shiny, with sparse fine indistinct punctures. Lateral lobe of mesoscutum red brown, meddle lobe black. Scutellum entirely black. Lower portion of mesopleuron and mesosternum white. Hind coxa and femur black.................................................................................... M. maculata Sheng, Sun & Li, 2020

-. Mesopleuron with distinct dense punctures and brownish yellow setae ( Fig. 32 ). Mesoscutum and scutellum almost entirely darkish red brown ( Fig. 33 ). Lower portion of mesopleuron whitish yellow ( Fig. 32 ); mesosternum red brown. Hind coxa and femur red brown............................................................. M. ruficosalis Li & Sun , sp. nov.

Figures

FIGURES 10–14. Mesoleptidea nigra Li & Sun, sp. nov., ♀, holotype (CBDPC). 10 Propodeum. 11 Tergite 1, dorsal view. 12 Tergite 1, lateral view. 13 Tergites 2–3, dorsal view. 14 Apical portion of metasoma, lateral view. Scale bars: 10–12, 14 = 0.3 mm; 13 = 0.5 mm.

FIGURES 4–9. Mesoleptidea nigra Li & Sun, sp. nov., ♀, holotype (CBDPC). 4 Head, lateral view. 5 Mesosoma, lateral view. 6 Mesoscutum and scutellum, dorsal view. 7 Fore wing. 8 Areolet. 9 Hind tarsus. Scale bars: 4–6= 0.3 mm; 7, 9 = 0.5 mm; 8 = 0.2 mm.

FIGURES 18–22. Mesoleptidea nigricoxalis Li & Sun, sp. nov., ♀, holotype (CBDPC). 18 Head, lateral view. 19 Mesosoma, lateral view. 20 Mesoscutum and scutellum, dorsal view. 21 Wings. 22 Hind tarsus. Scale bars: 18, 20 = 0.4 mm; 19, 22 = 0.5 mm; 21 = 1.0 mm.

FIGURES 37–41. Mesoleptidea ruficoxalis Li & Sun, sp. nov., ♀, holotype (CBDPC). 37 Propodeum. 38 Tergite 1, dorsal view. 39 Tergite 1, lateral view. 40 Tergite 2, dorsal view. 41 Apical portion of metasoma, lateral view. Scale bars: 37–40 = 0.3 mm; 41 = 0.2 mm.

FIGURES 31–36. Mesoleptidea ruficoxalis Li & Sun, sp. nov., ♀, holotype (CBDPC). 31 Head, lateral view. 32 Mesosoma, lateral view. 33 Mesoscutum and scutellum, dorsal view. 34 Wings. 35 Areolet. 36 Hind tarsus. Scale bars: 31–33 = 0.3 mm; 34 = 1.0 mm; 35 = 0.2 mm; 36 = 0.5 mm.

FIGURES 23–27. Mesoleptidea nigricoxalis Li & Sun, sp. nov., ♀, holotype (CBDPC). 23 Propodeum. 24 Tergite 1, dorsal view. 25 Tergite 1, lateral view. 26 Tergites 2–3, dorsal view. 27 Apical portion of metasoma, lateral view. Scale bars: 23–25 = 0.3 mm; 26 = 0.5 mm; 27 = 0.2 mm.