Balcha dictyota, 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 : 20-21

Balcha dictyota n. sp. ( Fig. 15 )

Type material. Holotype (♀, IZCAS): [ CHINA] “Peiping [Beijing], 13.III'35 / CNCI JDR­specm 2004­124 / Holotype Balcha dictyota Gibson ”; mounted by pin through right side of scutellum, right antenna with Fl 8 and clava, and right foreleg beyond trochanter missing.

Etymology. Formed from the Greek word diktyotos (reticulate), in reference to the largely reticulate mesoscutum and scutellum.

Description. FEMALE. Length, 8 mm. Antenna with scape yellow, pedicel brown and flagellum dark brown; scape widened apically but spindlelike and with outer surface uniformly setose; Fl 1 about 1.25 x as long as apical width and about 0.6 x as long as pedicel; Fl 2 about 1.2 x as long as clava. Head with punctures and interstices not contrasting distinctly in color, the face variably green to purple under different angles of light except parascrobal region with two dark regions having slight coppery luster under some angles of light, one ventrally between torulus and inner orbit and one dorsally between scrobal channel and inner orbit at juncture of punctate and more finely sculpture region; ocellar region and about anterior half of vertex posterior to ocelli dark, but occiput and outer orbit green to purple under some angles of light. Face (cf. Fig. 22) with setiferous punctures, the punctures on lower face and in dark region of lower parascrobal region shallower and closely crowded with mostly linear interstices so as to appear irregularly punctate­reticulate or rugulose, but medially on parascrobal region with distinct punctures separated by flat, finely coriaceous interstices and with about dorsal third of parascrobal region having very shallow, irregular, contiguous punctures so as to appear finely rugulose, and uniformly setose with white setae. Scrobal depression with channel and scrobes differentiated by transverse smooth band having slight greenish to purple luster under some angles of light, but otherwise dark or with slight coppery luster and punctate­reticulate ventrally to reticulate­coriaceous dorsally, with channel setose dorsally.

Pronotum dark with slight greenish luster anteriorly and more distinctly violaceous to purple posteriorly and laterally under some angles of light; coriaceous to coriaceousaciculate. Tegula yellow. Mesoscutum purple laterally, dorsally with separate parapsidal and notaular bands not contrasting distinctly with brighter metallic regions ( Fig. 15 ), the notaular band inconspicuously Y­ like because of slight greenish luster between notauli and extending very narrowly to scutellum with brighter green band on either side, and with longitudinal parapsidal band extending about half length of mesoscutum surrounded by slender green region that is separated from notaular band by purple band extending posteriorly within very slightly concave paramedial depression. Mesoscutum (cf. Fig. 38 ) punctate­alveolate laterally, dorsally the punctures shallower so as to be more reticulate and much smaller in region between notauli and near parapsidal line so as to be more punctulate­reticulate; with very shallow, obscure longitudinal depression anterior to level of inner margin of axilla, but sculpture not differentiated from surrounding cuticle; with white hairlike setae, the setae somewhat longer laterally and posteriorly but not distinctly lanceolate. Scutellum ( Fig. 15 ) green; shallowly, irregularly reticulate, the sculpture slightly shallower anteromedially. Metanotum dark with green or purple luster under some angles of light; dorsellum thick, with crenulate dorsal surface and coriaceous, bare, posterior surface; precrenular region of panel with single line of setae near anterior margin. Acropleuron with minutely and very finely coriaceous, inconspicuous subalar region separating punctate­alveolate prealar region from finely coriaceous­aciculate postalar region; with prealar region purple to green and subalar and postalar regions dark with purple luster under some angles of light. Lower mesepimeron punctate­reticulate. Metapleuron reticulate­rugulose over distinct coriaceous subsculpture. Propodeum mostly purple except plical region dark and vertical surface of callus bluish­green under some angles of light; paraspiracular region setose; callus dorsally comparatively smooth and shiny between setal pores but vertical surface punctate­reticulate, similar to sculpture of metapleuron; plical region bare, with carinate margin of foramen raised into flat, transverse posterior surface not distinctly ­like recurved to anterior margin of propodeum, but with strong median carina similar in appearance to lateral crenulae. Forewing hyaline; vannal area with subcubital line of setae extending over about apical half. Legs mostly yellowish­orange beyond coxae, but about apical half of outer surface of protibia brown, and meso­ and metatibia except for bases and apices more distinctly yellow.

Petiole composed of vertically raised anterior rim and longitudinally crenulate, lunate, horizontal surface about as long as propodeum medially, with distance between the crenulae distinctly greater than length of ridges or distance between propodeal plical crenulae. Gaster in dorsal view dark brown, and in lateral view with only obscure metallic lusters under some angles of light; about 1.75 x as long as head and mesosoma combined. Syntergum slightly more than one­third length of remaining gaster and in lateral view about 3.8 x as long as high; uniformly setose, sculptured and tapered posteriorly, with cercus at basal margin.

MALE. Unknown.

Biology. Unknown.

Discussion. Balcha dictyota is assigned to the elegans species­group as discussed under B. eximia , and may be the sister group of B. eximia + B. eximiassita based on shared presence of a crenulate petiole ( Fig. 47 ), though females of B. punctiscutum also have a crenulate petiole ( Fig. 44 ). Although a member of the elegans ­group, females of B. dictyota most closely resemble those of B. reticulata in mesoscutal color pattern ( Fig. 16 ) and mesonotal sculpture ( Fig. 38 ), as discussed under the latter species.

Figures

FIGURES 9–18. Mesosoma dorsal: 9, Balcha laciniosa; 10, B. cylindrica; 11, B. elegans; 12, B. indica (N. Am.); 13, B. eximia; 14, B. eximiassita; 15, B. dictyota; 16, B. reticulata; 17, B. anemeta; 18, B. splendida (nob = notaular band, pnb = paranotaular band, ppb = parapsidal band).

FIGURES 31–38. Mesosoma dorsal: 31, Balcha anemeta; 32, B. punctiscutum; 33, B. indica (N. Am.); 34, B. indica (holotype); 35, B. elegans; 36, B. laciniosa (not = notaulus, pl = parapsidal line); 37, B. eximiassita; 38, B. reticulata.

FIGURES 47–54. 47. Metanotum and propodeum: Balcha eximia. 48. B. indica (N. Am.): dorsellum and propodeal plical region. 49 and 50. Mesosoma, lateral: 49, B. punctiscutum; 50, B. indica (N. Am.). 51–54. Posterior half of acropleuron: 51, B. indica (holotype); 52, B. eximiassita; 53, B. anemeta; 54, B. levicollis (sar = subalar region of acropleuron).

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.