Helcon Nees, 1812

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

Genus Helcon Nees, 1812

( Fig. 4 )

Helcon Nees, 1812: 216 ; Lepeletier de St. Fargeau et Serville, 1827: 40; Watanabe, 1937: 2 –3; Hedqvist, 1967: 140 –143; Watanabe, 1972: 1 –18; van Achterberg, 1987: 263 –285; Chou et Hsu, 1998: 295 –297; Belokobylskij, 1998: 26 –40, 412– 415. Type species: Helcon tardator Nees , designated by Lepeletier de St. Fargeau et Serville, 1827.

Gymnoscelus Foerster, 1863: 255 . Type species: Helcon tardator Nees , by monotypy.

Edyia Cameron, 1905: 108. Type species: Edyia annulicornis Cameron , by monotypy.

Coelostephanus Kieffer, 1911: 232. Type species: Coelostephanus rufus Kieffer , by monotypy.

Diagnosis. Occipital carina distinctly curved above base of mandible, often nearly rectangularly angled with hypostomal carina and connected to hypostomal carina distinctly above base of mandible, resulting a distinct occipital flange; median lamella of frons distinct and normally acute posteriorly; propleuron convex; mesopleuron in front of prepectal carina steep, subvertical ( Fig. 4 C); prepectal carina present medio-ventrally; first discal cell of fore wing rather wide ( Fig. 4 A); hind femur comparatively slender and hardly or not serrate ( Figs 3 E, 4D); basal part of first metasomal sternite longer than wide and basally sculptured, well separated from tergite; second metasomal suture between first and second tergites narrow and shallow; fourth–sixth metasomal tergites well exposed behind third tergite.

Notes. In China only one species found ( H. sulcatus sp. nov.) from Palaearctic China (Jilin) . The holotype female of Coelostephanus rufus Kieffer, 1911 , from Mexico has been examined by the second author ( BMNH: “ Type, H.T. ”, “ B.M. Type Hym. 3.c.890”, “ Coelostephanus rufus Kieff. ”, “ Mex. / 59.70”, “ Determined by Dr. Kieffer ”; Fig. 2 ). Unfortunately, the hind legs are missing (except for a hind coxa), but the lowly situated antennal sockets (near level of lower quarter of eyes), the occipital carina curved ventrally, the large lamelliform occipital flange and the strongly convex propleuron indicate that it is an aberrant member of the genus Helcon Nees. It has the anterior half of the mesosternal sulcus and the precoxal sulcus largely absent, the first and second metasomal tergites smooth, the triangular median lamella of the frons distinct and the hind coxa hardly protruding basoventrally.

Figures

FIGURE 2 Helcon rufus (Kieffer), female, holotype. A, wings; B, mesosoma, lateral aspect; C, mesosoma, dorsal aspect; D, first-third metasomal tergites, dorsal aspect; E, fore and middle legs, lateral aspect; F, basal part of antenna; G, head, anterior aspect; H, head, dorsal aspect; I, head, lateral aspect; J, base of hind coxa, ventral aspect.

FIGURE 3. Acarohelcon varicolor gen. nov. et sp. nov., ♀, holotype. A, wings; B, mesosoma, lateral aspect; C, first and second metasomal tergites, dorsal aspect; D, hind femur and tibia, lateral aspect; E, habitus, lateral aspect; F, head, lateral aspect; G, head, dorsal aspect; H, propodeum, medio-dorsal aspect.

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.