Helcon sulcatus Yan et Chen

Yan, Cheng-Jin, Achterberg, Cornelis Van, He, Jun-Hua & Chen, Xue-Xin, 2017, Review of the tribe Helconini Foerster s. s. from China, with the description of 18 new species, Zootaxa 4291 (3), pp. 401-457 : 408-410

Helcon sulcatus Yan et Chen , sp. nov.

( Fig. 4 )

Description. Female. Female. Length of body (excluding ovipositor sheath) 10.4 mm, of setose part of ovipositor sheath 8.9 mm, of fore wing 8.1 mm.

Head. Antennal segments 37, length of third segment almost equal to length of fourth segment; length of last segment 1.4 times penultimate segment; length of third, fourth and penultimate segments 3, 3 and 1.4 times their width, respectively. length of maxillary palp 1.4 times height of head; head in frontal view 0.7 times as long as wide; length of eye in dorsal view almost equal to length of temple; malar suture complete; length of malar space almost equal to basal width of mandible, 0.5 times maximum width of eye. POL:OD:OOL = 7:11:21; vertex sparsely punctate and shiny, convex in lateral view ( Fig. 4 G); temple punctate; occipital carina complete and distinct; occipital flange rather slender and about as long as basal width of mandible; frons crest-shaped elevated and rugose-punctate laterally, dorso-medially smooth and shiny, medio-anteriorly weakly punctate with a protruding lamella (visible in lateral view) and the lamella hollow, with a deep triangular depression posteriorly and obtuse dorsally ( Fig. 4 H); clypeus densely reticulate-punctate dorsally, ventrally smooth, apico-ventrally truncate; face densely rugose-punctate medially, punctate laterally near mandible.

Mesosoma. Length 2.4 times its height; pronope large and triangular; side of pronotum antero-medially coarsely crenulate, subdorsally densely punctate, remainder reticulate-punctate; notauli narrow and deep, crenulate, coarsely rugose-reticulate posteriorly with a medial carina; scutellum sparsely punctate anteriorly, rugose-punctate posteriorly; scutellar sulcus with one carina and several lateral crenulae; precoxal sulcus complete and punctate; metanotum with a complete median carina; propodeum coarsely rugose-reticulate with a mediolongitudinal carina anteriorly ( Fig. 4 I).

Wings. Fore wing: 3.6 times as long as wide. 1-M weakly curved; pterostigma 3.3 times as long as wide; r:3- SR:SR1 = 10:11:71; 2-SR:3-SR:r-m=23:23:21; 1-M: m-cu = 25:16; SR1 straight. cu-a inclivous, interstitial; 1-CU1 absent; r-m inclivous. Hind wing: 1-M:1r-m = 18:28; cu-a inclivous.

Legs. Length of fore tarsus 1.3 times fore tibia; length of femur, tibia and basitarsus of hind leg 3.3, 10.0 and 7.0 times their width, respectively; length of outer and inner hind tibia spur 0.26 and 0.21 times basitarsus, respectively.

Metasoma. First tergite gradually widened posteriorly, dorsal carinae distinct in basal one-third, coarsely vermiculate-rugose; length of first tergite 1.4 times its apical width ( Fig. 4 D); second tergite rugose but apically smooth and in holotype also medially; third and following tergites smooth; ovipositor sheath 1.6 times as long as metasoma, 2.1 times as long as hind tibia, 2.1 times as long as mesosoma and 1.1 times as long as fore wing.

Colour. Black; palpi, tegulum, fore and middle legs, hind coxa and trochanters yellowish brown; antenna (except scapus) and hind femur dark reddish-brown; pterostigma reddish brown; wing membrane faintly brown and most veins brown.

Variation. Second tergite smooth medially or rugose; maximum width of eye of ♀ 1.8–2.0 times length of malar space.

Male. Unknown.

Material examined. Holotype, ♀, Mandchourie [= Jilin] prov., Kirin kao-lin-tze, 16.VI.1940, No. 34021339 ( ZJUH) . Paratypes: 1♀, id., but 4.VII.1940, No. 34021340 (ZJUH); 1♀, id., but 20.VII.1940, No. IOZ(E)1689990 (IZAS); 1♀, id., but 17.VII.1940, No. IOZ(E)1689991 (IZAS); 1♀, id., but 13.VII.1940, No. IOZ(E)1689992 (IZAS).

Comparative diagnosis. This new species is very similar to H. yezonicus Watanabe, 1931 , from Japan (sharing the black hind tarsus), but differs by having the first and second metasomal tergites rugose-punctate and basal half of third tergite punctate (basal tergites densely vermiculate-rugose and third tergite smooth in H. sulcatus ). Also similar to the Holarctic H. nunciator (Fabricius, 1793) because of the triangularly depressed posterior side of the frontal lamella and slender second tergite, but differs in having the hind tarsus black (yellowish brown in H. nunciator ), the first metasomal tergite subparallel-sided (distinctly widened posteriorly) and maximum width of eye of female 1.8–2.0 times length of malar space (1.3–1.6 times in H. nunciator ).

Distribution. China (Jilin).

Host. Unknown.

Etymology. Name derived from “sulcus” (Latin for groove), because of the grooved frontal lamella between the antennal sockets.

Figures

FIGURE 4. Helcon sulcatus sp. nov., ♀, holotype. A, fore wing; B, hind wing; C, mesosoma, lateral aspect; D, first and second metasomal tergites, dorsal aspect; E, hind femur and tibia, lateral aspect; F, habitus, lateral aspect; G, head, lateral aspect; H, head, dorsal aspect; I, propodeum, medio-dorsal aspect.