Balcha punctiscutum, 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 : 42-44

Balcha punctiscutum n. sp. (Figs. 3, 5, 7, 28, 32, 44, 49, 56, 57)

Type material. Holotype (♀, USNM): [ PHILIPPINES] “Island of Basilan, Baker / Cleonymini Gen. A, Balt. ‘58 [folded label] / CNCI JDR­SEM 2004­053 / Holotype Balcha punctiscutum Gibson ”; glued to point, right antenna missing beyond Fl 6, left middle leg detached and glued to point.

Paratype: ORIENTAL. [ MALAYSIA]: Sarawak, Gunong Mulu Natn. Park, V­ VIII.1978, P.M. Hammond, S. Marshall (1♀ BMNH, labelled “ Balcha carinaspis , det. Z. Bouček, 1984”, a manuscript name) .

Etymology. Formed from the Latin words punctum (small hole) and scutum (shield), in reference to the punctate mesoscutum that in part differentiates this species; a noun in apposition.

Description. FEMALE. Length, 13.5 mm. Antenna dark with scape yellowish­orange; scape widened apically but spindlelike and with outer surface uniformly setose; Fl 1 slightly longer than apical width and about two­thirds as long as pedicel; Fl 2 about 1.3–1.4 x as long as clava. Head with punctures and interstices not contrasting distinctly in color, the face varying from green to blue under some angles of light except upper parascrobal region with dark region adjacent to scrobal channel extending dorsally to dark ocellar region and vertex (Fig. 3), the posterior surface green to blue under most angles of light except dark region of vertex extending as posteriorly tapered band medially in region between posterior ocelli and laterally behind each ocellus. Face with setiferous punctures (Fig. 28), the punctures more closely crowded on lower face but deep and distinct even near oral margin, dorsally more widely separated by smooth and shiny interstices, except near ocelli abruptly coriaceous­rugulose and evenly setose with brownish setae. Scrobal depression with scrobes delimited from channel by transverse ridge and channel with 2 or 3 additional transverse ridges, otherwise smooth, shiny and dark or with green to blue luster under some angles of light, and either bare or with only very few setae dorsomedially near anterior ocellus.

Pronotum dark anteriorly, but posteriorly and laterally green to blue under most angles of light (Fig. 5); transversely strigose anteriorly, but dorsal surface posteriorly with distinct though variably crowded setiferous punctures ( Fig. 32 ). Tegula yellow. Mesoscutum green or blue to partly violaceous under some angles of light, with notaular and parapsidal bands variably distinct but not abruptly differentiated by well delimited margins or continuous to posterior margin of mesoscutum (Fig. 5). Mesoscutum ( Fig. 32 ) uniformly closely punctate with linear interstices variably conspicuously coriaceous, except posteriorly with transverse­crenulate furrow anterior to level of inner angle of axilla, the furrow narrowed anteriorly into line of irregular punctures extending to anterior margin adjacent to notaulus; with white hairlike setae, the setae laterally and posteriorly somewhat longer but not distinctly lanceolate. Scutellum (Fig. 5) similar in color to metallic regions of mesoscutum; closely punctate similar to mesoscutum, but with low mediolongitudinal ridge at least posteriorly ( Fig. 32 ). Metanotum green to blue except for brownish­hyaline dorsal margin of dorsellum; dorsellum ( Fig. 44 ) thin, in single vertical plane, with irregular longitudinal rugae over almost entire height, and bare; precrenular region of panel with single row of setae near anterior margin. Acropleuron (Figs. 7, 49) with only very obscurely differentiated subalar region but with small pit or depression posteromedially in smoother region, extensively punctate­alveolate anteriorly and quite abruptly, very finely coriaceous­aciculate posteriorly; sculptured region extensively green or bluish­green posteriorly, distinctly violaceous or purple anteriorly, or medially if darker or with slight greenish luster anteriorly, and with smoother surface dark with coppery to violaceous or green luster under some angles of light (Fig. 7). Lower mesepimeron and metapleuron similarly, closely punctate. Propodeum green or vertical surface of callus and plical region partly blue to purple under some angles of light; paraspiracular region bare excluding setae anterior to spiracle and one to several seta anterolaterally near plical region ( Fig. 44 ); callus uniformly closely punctate; plical region bare, with carinate margin of foramen not distinctly raised or ­like incurved to anterior margin of propodeum but surface irregularly crenulate ( Fig. 44 ). Forewing hyaline except medial fold slightly brownish; vannal area bare except for 2 widely spaced setae medially. Legs uniformly yellowish to yellowish­orange beyond coxae.

Petiole composed of anterior carina and longitudinally crenulate, lunate, horizontal surface of similar length and appearance as propodeal plical region ( Fig. 44 ). Gaster in dorsal view dark brown, but in lateral view all terga except syntergum green to purple; about 2.3 x as long as head and mesosoma combined. Syntergum elongate ( Fig. 56 ) and differentiated by submedial lateral notch into large basal portion surrounding ovipositor sheaths and slender, convex apical portion above sheaths, with cercus at about midlength of basal portion ( Fig. 57 ); uniformly setose and sculptured.

MALE. Unknown.

Biology. Unknown.

Discussion. The paratype is broken and lacks its syntergum and ovipositor, but presumably the missing structures were similar to those described for the holotype because otherwise the paratype and holotype are quite similar in structure, sculpture and setal patterns. The holotype mesoscutum is largely greenish with limited violaceous luster under some angles of light and with only quite poorly delimited notaular and parapsidal bands (Fig. 5), the mesoscutum being dark with a slight coppery luster between the notauli for about half its length and in diffuse regions on either side of quite distinct parapsidal lines near the apex of each line. The notaular band is separated from the parapsidal band by a green, slightly effaced line of punctures that expand posteriorly into a deeper, transversely crenulate furrow anterior to the inner margin of the axilla ( Fig. 32 ). Although superficially appearing as notauli, anteriorly the sinuous lines of differentiated sculpture are immediately lateral to obscure, coriaceous­punctulate lines, which are the true notauli. The mesoscutum of the paratype is much more extensively dark with violaceous luster, except being greenish to blue anteriorly lateral to the parapsidal line and posterodorsally lateral to the notaulus. However, the paratype female is quite dirty, which may affect observed color, and additional specimens are required before an accurate color description is possible for the species. The paratype also differs slightly in propodeal setal pattern. There is a complete line of setae along the anterior margin of the callus mesally to the plical region, including a few setae forming a small setal patch adjacent to the crenulate furrow that differentiates the callus and plical region. The callus of the holotype has only a single line of sparse, long setae along its anterior margin mesally to the plical region ( Fig. 44 ). Of the species having a bare paraspiracular region, B. punctiscutum is the only one having setae extending along its anterior margin distinctly beyond the level of the inner margin of the spiracle to the plical region.

The uniformly coarsely punctate mesoscutum ( Fig. 32 ) differentiates females of B. punctiscutum from all other species of the genus, which have an alveolate to reticulatealveolate mesoscutum ( Figs. 31, 33–42 ). Females are also differentiated by their elongate, subdivided syntergum ( Fig. 56 ) that, although somewhat similar to the syntergum of B. camptogastra females ( Fig. 59 ), is unique in having the cercus conspicuously displaced from the base of the syntergum ( Fig. 57 ). Balcha punctiscutum is assigned to the anemeta ­ group based on the presence of a thin dorsellum. Because of its bare plical region, morphologically it is most similar to B. reticulifrons within the anemeta ­group, but the only shared feature that may support a close relationship is the largely bare forewing vannal area.

Figures

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 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.

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.