Balcha reticulifrons, 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 : 48-50

Balcha reticulifrons n. sp. (Fig. 4)

Type material. Holotype (♀, BMNH): [ SRI LANKA] “Kandy, 10.02 / CEYLON [hand printed over Assam], R. Turner, 1905 – 125 / CNCI JDR­specm 2004­127 / Holotype Balcha reticulifrons Gibson ”; mounted by pin through scutellum to card, right antenna beyond Fl 5 missing and right forewing glued to card, otherwise entire, but dirty.

Etymology. Formed from the Latin words reticulatus (netlike) and frons (brow), in reference to the reticulate sculpture of the face (Fig. 4), which is unique for this species of Balcha ; a noun in apposition.

Description. FEMALE. Length, 5.8 mm. Antenna dark with scape and pedicel yellowish to yellowish­orange; 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 only about 0.9 x as long as clava. Head with face (Fig. 4) mostly green but interstices coppery to reddish under some angles of light and parascrobal region near dorsal limit of scrobal depression with transverse dark band not quite extending to inner orbit; ocellar region and about anterior half of vertex posterior to ocelli dark, the dark region extending only slightly more posteriorly medially behind posterior ocelli and laterally along upper inner orbit, with occiput and along outer orbit greenish. Face with lower face and parascrobal region almost uniformly reticulate, the cells multisided and with ridgelike interstices, except about dorsal quarter of parascrobal region with distinctly smaller reticulations and uniformly setose with brownish setae. Scrobal depression with scrobes and about ventral half of channel transversely strigose­rugulose and green to purple under some angles of light except for more violaceous transverse band ventrally in channel, but channel dorsally dark, coriaceous­reticulate and setose.

Pronotum dark anteriorly and posteriorly bright green; smooth and shiny between setal pores. Tegula yellow. Mesoscutum primarily green with interstices of punctures coppery to slightly reddish, except for broad dark region anteromedially, the notaular and parapsidal bands apparently contiguous and extending only about half length of mesoscutum. Mesoscutum almost uniformly reticulate­alveolate except punctures slightly shallower in dark regions; with relatively deep and narrow longitudinal furrow over about posterior half anterior to level of inner angle of axilla; with white to brownish setae, the setae longer and slightly lanceolate laterally. Scutellum darker than mesoscutum posteriorly, the punctures dark and interstices greenish under some angles of light (see discussion); coarsely punctate, the punctures more circular to oval but interstices about same width as on mesoscutum. Metanotum green except for brownish­hyaline dorsal margin of dorsellum; dorsellum thin, in single vertical plane, punctulate­rugulose, and bare; precrenular region of panel with single row of setae near anterior margin. Acropleuron with at most an obscure, minutely and very finely coriaceous subalar region, but punctate­alveolate anterior to, and smooth and shiny posterior to, an imaginary oblique line drawn between base of tegula and anterolateral corner of mesocoxa; punctured region violaceous or coppery under some angles of light and smooth region dark with purple or violaceous luster under some angles of light. Lower mesepimeron and metapleuron punctulatereticulate to rugulose. Propodeum green except vertical surface of callus purple; paraspiracular region bare, the setae anterior to spiracle extending mesally only to about level of inner margin of spiracle; callus comparatively smooth and shiny dorsally but laterally reticulate­rugulose; plical region bare, with carinate margin of foramen ­like recurved to anterior margin of propodeum as fine median carina similar in appearance to crenulae lateral to median carina. Forewing hyaline; vannal area with 2 widely spaced setae within about apical third. Legs with trochanters, femora except extreme apices, and protibia medially brown, otherwise yellow.

Petiole composed of anterior carina and lunate, horizontal surface with median carina but otherwise quite shiny without evident crenulae. Gaster in dorsal view dark, in lateral view terga with greenish luster dorsally and distinct violaceous luster ventrally; about 1.2 x as long as head and mesosoma combined. Syntergum short and stubby, only about 0.2 x as long as remaining gaster and in lateral view about 1.5 x as long as high, with cercus at basal margin; uniformly setose and sculptured.

MALE. Unknown.

Biology. Unknown.

Discussion. The unique female of B. reticulifrons is quite dirty and for this reason the described color probably is not entirely accurate for the species, but females are uniquely distinguished by having the face almost uniformly reticulate with linear interstices. Furthermore, the facial setae arise virtually from the interstices forming the reticulations. Other known species of Balcha have at least the parascrobal region punctate or punctatealveolate with flat interstices and the facial setae arising variably distinctly closer to the middle of the punctures. It is also the only species other than B. punctiscutum that has a distinct furrow on the mesoscutum anterior to the inner margin of the axilla.