Blacus Nees, 1819

Lu, Qian-Yu, Chai, Hong-Fei, Achterberg, Cornelis Van, Tang, Pu & Chen, Xue-Xin, 2024, The first report of subgenus Blacus Nees, 1819 (Hymenoptera, Braconidae, Brachistinae) from China, Zootaxa 5471 (5), pp. 501-535 : 502-503

publication ID	https://doi.org/ 10.11646/zootaxa.5471.5.1
publication LSID	lsid:zoobank.org:pub:3D7BA3AC-A3BE-4F89-9178-D200841F052F
DOI	https://doi.org/10.5281/zenodo.12520150
persistent identifier	https://treatment.plazi.org/id/038287B7-FFE4-FFBF-7EDE-FDB2A5B44652
treatment provided by	Plazi
scientific name	Blacus Nees
status

Treatment

Key to Chinese species of subgenus Blacus Nees View in CoL View at ENA

1 Parastigma of ♀ medium-sized to large and comparatively wide, distinctly differentiated from vein C+SC+ R ( Figs 26E View FIGURE 26 , 28H View FIGURE 28 ) and first discal cell acute anteriorly....................................................................... 2

- Parastigma of ♀ small and narrow, less differentiated from vein C+SC+ R, and first discal cell acute anteriorly ( Figs 2I View FIGURE 2 , 4J View FIGURE 4 , 12F View FIGURE 12 , 20H View FIGURE 20 , 24G View FIGURE 24 ); if parastigma of ♀ medium-sized to large and distinctly differentiated from vein C+SC+ R, then first discal cell truncate anteriorly ( Figs 6H View FIGURE 6 , 8J View FIGURE 8 , 10I View FIGURE 10 , 16I View FIGURE 16 , 18I View FIGURE 18 , 22E View FIGURE 22 , 30I View FIGURE 30 )....................................................... 4

2 Length of ovipositor sheath 0.22 × length of fore wing, 0.9 × length of hind femur, 0.6 × length of hind tibia; 1-CU1: 2-CU1 ≈ 1: 2 ( Fig. 14I View FIGURE 14 ); length of malar space 1.6 × basal width of mandible; body and fore wing comparatively short; length of hind femur 4.6 × its width..................................................... Blacus (Blacus) longicornis sp. nov.

- Length of ovipositor sheath 1.5–2.4 × length of fore wing, 5.0–7.9 × length of hind femur, 3.5–5.5 × length of hind tibia ( Figs 26I View FIGURE 26 , 28I View FIGURE 28 ); 1-CU1: 2-CU1 = 1: 4 to 1: 6 ( Figs 26E View FIGURE 26 , 28H View FIGURE 28 ); length of malar space 2.0–2.4 × basal width of mandible; body and fore wing comparatively long; length of hind femur 5.5 × its width.................................................. 3

3 Length of ovipositor sheath 1.5 × length of fore wing, 5.0 × length of hind femur, 3.5 × length of hind tibia and approx. as long as body; length of malar space 2.0 × basal width of mandible; length of first metasomal tergite 1.7 × its apical width ( Fig. 26H View FIGURE 26 ); metasomal tergites slightly punctate; body black................................ Blacus (Blacus) rugifacialis sp. nov.

- Length of ovipositor sheath 2.4 × length of fore wing, 7.9 × length of hind femur, 5.45 × length of hind tibia and approx. twice as long as body; length of malar space 2.4 × basal width of mandible; length of first metasomal tergite 1.9–2.1 × its apical width ( Fig. 28G View FIGURE 28 ); metasomal tergites partly distinctly rugose; body brown............ Blacus (Blacus) tianmushanensis sp. nov.

4 Parastigma of fore wing less differentiated from vein C+SC+R and first discal cell acute anteriorly ( Figs 2I View FIGURE 2 , 24G View FIGURE 24 )......... 5

- Parastigma of fore wing distinctly differentiated from vein C+SC+R and first discal cell truncate anteriorly ( Figs18I View FIGURE 18 , 30I View FIGURE 30 ).. 9

5 Vein CUla of fore wing nearly at same level as vein 2-CU1 ( Figs 2I View FIGURE 2 , 24G View FIGURE 24 ); vein 2-M absent ( Figs 2I View FIGURE 2 , 24G View FIGURE 24 ); malar space distinctly longer than basal width of mandible ( Figs 2B View FIGURE 2 , 24B View FIGURE 24 ).................................................. 6

- Vein CUla of fore wing distinctly bent basally, distinctly below level of vein 2-CU1 ( Figs 7H View FIGURE 7 , 12F View FIGURE 12 ); vein 2-M and ratio of length of malar space to basal width of mandible variable........................................................... 7

6 Antenna more robust ( Fig. 2C View FIGURE 2 ); frontal suture present; vein 2-1A of fore wing short ( Fig. 2I View FIGURE 2 ); length of first metasomal tergite 1.7 × its apical width ( Fig. 2G View FIGURE 2 ); length of ovipositor sheath 0.21–0.22 × length of fore wing; basal half of metasoma brown ventrally ( Fig. 1 View FIGURE 1 ); hind coxa and hind trochanter yellow ( Fig. 2H View FIGURE 2 )............. Blacus (Blacus) adustiabdominus sp. nov.

- Antenna slender ( Fig. 24C View FIGURE 24 ); frontal suture absent; vein 2-1A of fore wing long ( Fig. 24G View FIGURE 24 ); length of first metasomal tergite 2.1 × its apical width ( Fig. 24E View FIGURE 24 ); length of ovipositor sheath 0.30 × length of fore wing; basal half of metasoma reddish ventrally ( Fig. 23 View FIGURE 23 ); hind coxa and hind trochanter yellowish-red ( Fig. 24H View FIGURE 24 )............... Blacus (Blacus) rufiabdominus sp. nov.

7 Marginal cell of fore wing comparatively large ( Fig. 20H View FIGURE 20 ); vein 3-SR+SR1 of fore wing straight, and reaching apex of fore wing; vein 2-M of fore wing present ( Fig. 20H View FIGURE 20 ); propodeal tubercles distinct and large............................................................................................. Blacus (Blacus) pappianus Haeselbarth, 1973 View in CoL

- Marginal cell of fore wing comparatively small ( Figs 4J View FIGURE 4 , 12F View FIGURE 12 ); vein 3-SR+SR1 of fore wing curved basally, and not reaching apex of fore wing; vein 2-M of fore wing absent or indistinct ( Figs 4J View FIGURE 4 , 12F View FIGURE 12 ); propodeal tubercles absent................. 8

8 First metasomal tergite 1.3–1.5 × longer than its apical width ( Fig. 12E View FIGURE 12 ); marginal cell of fore wing comparatively small ( Fig. 12F View FIGURE 12 ); apical part of pterostigma less wide; vein 3-SR+SR1 of fore wing distinctly curved basally ( Fig. 12F View FIGURE 12 ); antenna more slender ( Fig. 12C View FIGURE 12 )................................................... Blacus (Blacus) leptostigma Ruthe, 1861 View in CoL

- Length of first metasomal tergite 1.6–1.8 × longer than its apical width ( Fig. 4G View FIGURE 4 ); marginal cell of fore wing comparatively large ( Fig. 4J View FIGURE 4 ); apical part of pterostigma wider; vein 3-SR+SR1 of fore wing slightly curved basally ( Fig. 4J View FIGURE 4 ); antenna more robust ( Fig. 4C View FIGURE 4 ).......................................................... Blacus (Blacus) exilis ( Nees, 1811) View in CoL

9 Length of ovipositor sheath 0.50 × length of fore wing ( Fig. 29 View FIGURE 29 ); antenna of ♀ slender ( Fig. 30C View FIGURE 30 ); length of body 3.5 mm and length of fore wing 3.2 mm ( Fig. 29 View FIGURE 29 )......................................... Blacus (Blacus) xizangensis sp. nov.

- Length of ovipositor sheath less than 0.40 × length of fore wing; antenna of ♀ robust ( Figs 6C View FIGURE 6 , 8C, 8E View FIGURE 8 , 10C View FIGURE 10 , 16C View FIGURE 16 , 18C View FIGURE 18 , 22C View FIGURE 22 ); length of body and fore wing variable.................................................................... 10

10 Third antennomere of ♀ very robust and dark brown ( Fig. 18C View FIGURE 18 ); scutellar sulcus with strongly developed carinae beside medio-longitudinal carina ( Fig. 18D View FIGURE 18 ); basal half of antenna of ♀ largely moniliform ( Fig. 18C View FIGURE 18 )..; [first metasomal tergite 1.4–1.9 × longer than wide apically].............................................. Blacus (Blacus) paganus Haliday, 1835 View in CoL

- Third antennomere of ♀ slender and often yellowish brown ( Figs 8C View FIGURE 8 , 10C View FIGURE 10 , 16C View FIGURE 16 , 22C View FIGURE 22 , 6C View FIGURE 6 ); scutellar sulcus smooth or with some weak or indistinct rugae beside medio-longitudinal carina ( Figs 6E View FIGURE 6 , 8D View FIGURE 8 , 22D View FIGURE 22 ); basal half of antenna of ♀ not moniliform ( Figs 6C View FIGURE 6 , 8C View FIGURE 8 , 10C View FIGURE 10 , 16C View FIGURE 16 , 22C View FIGURE 22 )............................................................................... 11

11 Third antennomere dark brown; length of first tergite 1.5 × its apical width ( Fig. 10G View FIGURE 10 ) and propodeal tubercles indistinct ( Fig. 10E View FIGURE 10 ); vein 1-CU1 of fore wing as long as vein 2-CU1 ( Fig. 10I View FIGURE 10 ); [frontal suture (= medial suture of frons) absent or obsolescent ( Figs 10A, B View FIGURE 10 )]............................................................ Blacus (Blacus) hebeiensis sp. nov.

- Third antennomere brownish yellow or yellow; length of first tergite 1.7–2.6 × its apical width ( Figs 6F View FIGURE 6 , 8H View FIGURE 8 , 16G View FIGURE 16 , 22G View FIGURE 22 ), if about 1.7 × then propodeal tubercles distinct ( Fig. 6E View FIGURE 6 ); vein 1-CU1 of fore wing much shorter than vein 2-CU1 ( Figs 8J View FIGURE 8 , 16I View FIGURE 16 )... 12

12 Length of first tergite 1.7 × its apical width and distinctly widened apically ( Fig. 6F View FIGURE 6 ); propodeal tubercles large ( Fig. 6E View FIGURE 6 ); apical half of antenna of ♀ distinctly moniliform ( Fig. 6C View FIGURE 6 ); mesoscutal lobes anteriorly darker than posteriorly ( Fig. 6E View FIGURE 6 ).............................................................................. Blacus (Blacus) flavimaculus sp. nov.

- Length of first tergite 2.0–2.6 × its apical width and hardly widened apically or parallel-sided ( Figs 8H View FIGURE 8 , 16G View FIGURE 16 , 22G View FIGURE 22 ); propodeal tubercles small ( Figs 8F View FIGURE 8 , 16D View FIGURE 16 , 22F View FIGURE 22 ); apical half of antenna of ♀ hardly or not moniliform ( Figs 8C, 8E View FIGURE 8 , 16C View FIGURE 16 , 22C View FIGURE 22 ); mesoscutal lobes anteriorly as dark as posteriorly ( Figs 16E View FIGURE 16 , 22D View FIGURE 22 ) or slightly darker ( Fig. 8D View FIGURE 8 )................................. 13

13 Head in dorsal view sparsely setose ( Fig. 8A View FIGURE 8 ); first metasomal tergite aciculate-rugose ( Fig. 8H View FIGURE 8 ); antenna of ♀ more slender and less conspicuously setose ( Figs 8C, 8E View FIGURE 8 ); [mesoscutal lobes reddish-brown ( Fig. 8D View FIGURE 8 )]................................................................................................ Blacus (Blacus) forticornis Haeselbarth View in CoL

- Head in dorsal view densely setose ( Figs 16A View FIGURE 16 , 22A View FIGURE 22 ); first metasomal tergite rugose or reticulate-rugose ( Figs 16G View FIGURE 16 , 22G View FIGURE 22 ); antenna of ♀ less slender and more conspicuously setose ( Figs 16C View FIGURE 16 , 22C View FIGURE 22 )....................................... 14

14 Dorsal face of propodeum distinctly oblique in lateral view ( Fig. 16D View FIGURE 16 ); vein 3-SR+SR1 of fore wing about 6.0 × longer than vein r ( Fig. 16I View FIGURE 16 ); frontal suture (= medial suture of frons) absent or obsolescent ( Fig. 16A View FIGURE 16 )....................................................................................... Blacus (Blacus) longipennis ( Gravenhorst, 1807) View in CoL

- Dorsal face of propodeum subhorizontal in lateral view ( Fig. 22F View FIGURE 22 ); vein 3-SR+SR1 of fore wing about 8.0 × longer than vein r ( Fig. 22E View FIGURE 22 ); frontal suture more or less developed......................... Blacus (Blacus) radialis Haeselbarth, 1973 View in CoL