Blacus ( Blacus ) rufiabdominus, Lu & Chai & Achterberg & Tang & Chen, 2024

Blacus ( Blacus) rufiabdominus sp. nov.

( Figs 23–24 View FIGURE 23 View FIGURE 24 )

Material examined. Holotype: ♀, China, Zhejiang, Deqing, Fatou , 27.V.1995, He Junhua, No. 957342 ( ZJUH). Description. Female. Length of body 2.2 mm, length of fore wing 1.8 mm.

Head. Antennomeres 17, slender ( Fig. 24C View FIGURE 24 ); length of first flagellomere 1.25 × length of second flagellomere; length of first, second and penultimate flagellomere 5.0, 4.0 and 1.7 × their width, respectively; maxillary palp approx. 1.0 × height of head; occipital carina complete ( Fig. 24A View FIGURE 24 ); frontal suture absent; OOL: OD: POL = 8: 3: 5; length of eye in dorsal view 0.7 × length of temple; face smooth ( Fig. 24B View FIGURE 24 ); malar suture absent, length of malar space 1.8 × basal width of mandible.

Mesosoma. Length of mesosoma 1.8 × its height; side of pronotum rugose ventrally, smooth dorsally ( Fig. 24F View FIGURE 24 ); precoxal sulcus complete, wide and reticulate-rugose ( Fig. 24F View FIGURE 24 ); notauli complete and narrow, nearly smooth ( Fig. 24D View FIGURE 24 ); mesoscutal lobes largely glabrous ( Fig. 24D View FIGURE 24 ); scutellum largely smooth, its lateral carina complete, slightly protruding apically; propodeal tubercles absent; surface of propodeum reticulate-rugose, medial area absent ( Fig. 24E View FIGURE 24 ).

Wings. Fore wing: parastigma slightly differentiated from vein C+SC+ R, first discal cell acute anteriorly; vein 3-SR+SR1 of fore wing nearly straight; vein CUla of fore wing nearly at same level as vein 2-CU1; 1-CU1: 2-CU1 = 3: 14; vein 2-M absent ( Fig. 24G View FIGURE 24 ).

Legs. Hind coxa slightly rugose; hind femur swollen apically, length of femur, tibia and basitarsus of hind leg 4.7, 12.25 and 10.0 × their width, respectively.

Metasoma. Length of first tergite 2.1 × its apical width, nearly parallel-sided, reticulate-rugose ( Fig. 24E View FIGURE 24 ); remainder of tergites smooth ( Fig. 24E View FIGURE 24 ); length of ovipositor sheath 0.30 × length of fore wing, 1.3 × length of hind femur, 0.9 × length of hind tibia.

Colour. Blackish; 4 basal antennomeres, palpi, tegulae, pterostigma, parastigma, veins and all legs yellow; pronotum, mandible, hind coxa and hind trochanter yellowish-red; basal half of metasoma reddish; ovipositor and sheath reddish-brown; wing membrane slightly infuscated.

Male. Unknown.

Biology. Unknown.

Distribution. China ( Zhejiang).

Etymology. The specific name rufiabdominus refers to the reddish metasoma and derived from “ rufus ” (Latin for red and reddish) and “ abdomen ” (Latin for abdomen).

Notes. The new species is similar to B. ( B.) inopinus van Achterberg, 1976 because parastigma is small and narrow, slightly differentiated from vein C+SC+R, first discal cell of fore wing acute anteriorly, scutellum largely smooth, ovipositor sheath somewhat longer than hind femur, vein CUla of fore wing nearly at same level as vein 2-CU1, vein 2-M of fore wing absent, propodeal tubercle absent, length of ovipositor sheath 0.30 × length of fore wing, and basal half of metasoma reddish, but differs by having narrow and nearly smooth notauli (wide and distinctly crenulate in B. ( B.) inopinus ), length of first metasomal tergite 2.1 × its apical width (1.7 ×), posterior surface of propodeum less reticulate (more reticulate), antenna equally wide overall (narrowed medially and widened apically), and length of malar space 1.8 × basal width of mandible (1.2 ×).

This new species is also similar to B. ( B.) adustiabdominus sp. nov., but differs by having more slender antenna (more robust in B. ( B.) adustiabdominus ), frontal suture absent (present), vein 2-1A of fore wing long (short), length of first metasomal tergite 2.1 × its apical width (1.7 ×), basal half of metasoma reddish ventrally (yellow), hind coxa and hind trochanter yellowish-red (yellow), length of ovipositor sheath 0.30 × length of fore wing (0.21–0.22 ×).