Balcha enoptra, Gibson, 2005

Gibson, Gary A. P., 2005, The world species of Balcha Walker (Hymenoptera: Chalcidoidea: Eupelmidae), parasitoids of wood-boring beetles, Zootaxa 1033 (1), pp. 1-62 : 25-27

Balcha enoptra n. sp. (Figs. 6, 23, 42, 45, 55)

Type material. Holotype (♀, IZCAS): [ CHINA] “ Yunnan, 20 km. S.W. Cheli [ Yunjinghong ], 650 m., 9.IV.1957, D. Panfilov [two identical labels, upper in Russian and lower in Chinese] / CNCI JDR­SEM 2004­068”; glued to point, Fl 8 and clava of right antenna, right wings except for about basal quarter of forewing, and left metatarsus missing.

Etymology. Formed from the Greek word enoptron (mirror), in reference to the dorsally smooth and shiny syntergum of females of this species ( Fig. 55 ).

Description. FEMALE. Length, 7 mm. Antenna dark except scape, pedicel and Fl 1 yellowish­orange; scape widened apically but spindlelike and with outer surface uniformly setose; Fl 1 about as long as apical width and half as long as pedicel; Fl 2 very slightly longer than clava. Head with punctures of lower face green and those of parascrobal region blue to purple under most angles of light in contrast to dark or slightly coppery interstices (cf. Fig. 2), and with vertex and posterior surface of head mostly dark but occiput dorsally with green to bluish band in line with posterior ocellus and with upper outer orbit narrowly bluish to green. Face (Fig. 23) with setiferous punctures separated by distinctly coriaceous interstices, the punctures on lower face shallower and more closely crowded with mostly ridgelike interstices compared to more widely separated punctures over about ventral twothirds of parascrobal region, except about dorsal third of parascrobal region quite abruptly coriaceous with only tiny, shallow setiferous depressions so as to be flat and uniformly setose with dark setae. Scrobal depression with scrobes transversely strigose and dark to purple under different angles of light; channel smooth, shiny, and dorsally setose, with two bright metallic bands or paramedial spots, a purple to green transverse band ventrally and paramedial green spots subdorsally, the region between the bands and below anterior ocellus dark with slight coppery luster under some angles of light (cf. Fig. 2).

Pronotum dark anteriorly, but posteriorly and laterally green to purple under some angles of light; distinctly coriaceous. Tegula yellowish­brown. Mesoscutum with green to blue punctures and dark interstices under most angles of light except anteriorly for dark notaular and parapsidal bands, the notaular band slightly greenish between notauli under some angles of light and parapsidal band extending only about half length of mesoscutum, with notaular and parapsidal bands only obscurely separated by slightly greenish band of punctures under some angles of light and notaular band only obscurely extending to scutellum (Fig. 6). Mesoscutum ( Fig. 42 ) alveolate laterally and dorsally posterior to level of notauli, with punctures slightly transverse between notaulus and parapsidal line, and distinctly smaller, more reticulate­punctate, between notauli; without distinct depression anterior to level of inner margin of axilla; with brownish hairlike setae dorsally but laterally with slightly longer, white but not distinctly lanceolate setae. Scutellum (Fig. 6) dark with violaceous luster or slight greenish tinge under some angles of light; coriaceousgranular with tiny setiferous punctures near posterior margin, but sculpture mostly aligned into shallow, setiferous furrows and irregular, low, rounded longitudinal ridges, without a differentiated mediolongitudinal ridge ( Fig. 42 ). Metanotum dark with green to bluish luster under some angles of light; dorsellum thick, with crenulate dorsal surface and coriaceous, bare, posterior surface; precrenular region of panel with single row of setae near anterior margin ( Fig. 45 ). Acropleuron with slender, minutely and very finely coriaceous subalar region separating punctate­alveolate prealar region from finely coriaceous­aciculate postalar region; prealar region with punctures green to violaceous or blue compared to darker interstices under most angles of light, but subalar and postalar regions dark or with slight violaceous luster. Lower mesepimeron shallowly punctatereticulate. Metapleuron extensively punctate­ or reticulate­rugulose over distinct coriaceous subsculpture except more uniformly coriaceous dorsally and with crenulate furrow along posterior margin and anterior margin ventrally. Propodeum ( Fig. 45 ) mostly green dorsally but callus purple to violaceous under different angles of light; paraspiracular region bare, the setae anterior to spiracle extending mesally only to about level of inner margin of spiracle; callus at most finely coriaceous between setal pores; plical region bare, with carinate margin of foramen ­like recurved to anterior margin of propodeum as median carina similar in appearance to crenulae lateral to median carina ( Fig. 45 ). Forewing hyaline; vannal area with subcubital setal line extending over about apical half. Legs mostly yellowish­orange, but profemur dark brown with slight green luster under some angles of light and meso­ and metatibiae more distinctly yellowish apically.

Petiole ( Fig. 45 ) composed almost entirely of vertically raised, smooth and shiny rim. Gaster in dorsal view dark brown, in lateral view with quite distinct green to violaceous luster on Gt 1 but only very obscure metallic luster on remaining terga; about 1.1 x as long as head and mesosoma combined. Syntergum ( Fig. 55 ) only about 0.2 x as long as remaining gaster and in lateral view about as long as high; in lateral view uniformly setose, but in dorsal view with low convex, smooth and shiny bare region about 2.5 x as long as wide posterior to transverse setose band [in holotype, setose band posterior to bare, coriaceous region normally overlain by posterior margin of penultimate tergum, see below].

MALE. Unknown.

Biology. Unknown.

Discussion. The unique female has the apex of the penultimate gastral tergum retracted from the syntergum so that the base of the syntergum is exposed ( Fig. 55 ), unnaturally. The base of any gastral tergum normally is overlain by an apical portion of the preceding tergum, with the overlain portion being bare so that the surfaces slide easily. Consequently, the bare basal portion of the syntergum seen in the holotype ( Fig. 55 ) probably will not be visible for all females. Relative length of the syntergum given in the description was measured from the anterior margin of the setose band to the posterior margin of the syntergum. The mirrorlike dorsal surface of the short syntergum ( Fig. 55 ) uniquely distinguishes females of B. enoptra from those of other Balcha . It is unknown whether males have a similar syntergal structure. Females of B. enoptra also have the mesoscutum comparatively uniformly alveolate posterior to the parapsidal and notaular bands, the punctures dorsally being quite similar in size and depth compared to the punctures laterally ( Fig. 42 ).

Figures

FIGURES 55–59. 55. Balcha enoptra: syntergum. 56 and 57. B. punctiscutum: 56, syntergum; 57, base of syntergum. 58 and 59. B. camptogastra: 58, lateral habitus; 59, syntergum.

FIGURES 39–46. 39–42. Mesosoma, dorsal: 39, Balcha cylindrica; 40, B. splendida; 41, B. camptogastra; 42, B. enoptra. 43–46. Metanotum and propodeum: 43, B. levicollis; 44, B. punctiscutum; 45, B. enoptra (cal = callus, dor = dorsellum, pcr = precrenular region of metanotal panel, ppr = propodeal plical region, psr = paraspiracular region); 46, B. elegans.