Balcha eximiassita, 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 : 29-31

Balcha eximiassita n. sp. ( Figs. 14 , 37 , 52 )

Type material. Holotype (♀, USNM): “ THAILAND, Nkn. Ratcha. [Nakhon Ratchasima] Prov., Kakhon Ratchasima , 60 km. S., 2­4.III.1971, P. & P. Spangler / Sakaerat Expt. Sta., 14°30'N 101°55'E, 300­600 meters / collected in Malaise Trap / CNCI JDR­SEM 2004­ 060 / Holotype Balcha eximiassita Gibson ”; pinned through posterior of mesoscutum, entire but right hind wing glued to top label.

Paratypes: ORIENTAL. INDIA: Mahé , Malabar, 1919, J. de Gaulle (1♀ MNHN) . VIETNAM: Tonkin , Hoa­Binh, III.1937, A. de Cooman (3♀ IZCAS) , VIII.1918, R.V. de Salvaza (1♀ BMNH) .

Etymology. Formed from the species name eximia (exceptional or extraordinary) and the Latin word assitus (near), in reference to the morphological similarity of females of the two putative species.

Description. FEMALE. Length, 12–16 mm. Antenna dark except scape usually orange; scape widened apically but spindlelike and with outer surface uniformly setose; Fl 1 quadrate to slightly transverse and about half as long as pedicel; Fl 2 about 1.5–1.7 x as long as clava. Head with punctures and interstices not contrasting in color on face, the face mostly green or more bluish­purple ventrally under some angles of light, except interantennal region and usually lower parascrobal region narrowly purple or dark along scrobes, and upper parascrobal region often with slender region of bright­coppery luster along margin of scrobal channel; ocellar region and about anterior half of vertex posterior to ocelli dark or coppery, but green to blue along upper inner orbit from about level of posterior ocellus, and more extensively blue to purple on occiput and behind outer orbit. Face with setiferous punctures (cf. Fig. 20), the punctures more closely crowded on lower face but deep and distinct even near oral margin, more widely separated by flat, smooth or only very finely and inconspicuously coriaceous interstices on parascrobal region, except about dorsal quarter to third of region uniformly setose, flat and punctulate­coriaceous, the punctures much smaller, shallower, crowded and with distinct coriaceous subsculpture (cf. Fig. 20). Scrobal depression with scrobes dark, smooth and shiny ventrally but distinctly punctate­reticulate dorsally; channel smooth and shiny with green to blue or purple luster ventrally, but dorsally dark or with slight coppery luster and finely coriaceous and setose toward anterior ocellus.

Pronotum dark anteriorly, but posteriorly and laterally blue to purple; only very finely coriaceous­aciculate between setal pores. Tegula yellow. Mesoscutum laterally narrowly purple along margin and green between purple region and parapsidal band, dorsally with notaular and parapsidal bands extending to scutellum, the bands joined distinctly anterior to scutellum and with notaular band having concave sides abruptly widened in about posterior third or quarter to form parallel longitudinal margins anterior to scutellum ( Fig. 14 ), and with greenish paranotaular band obviously separated from scutellum. Mesoscutum ( Fig. 37 ) punctate­alveolate laterally, dorsally the punctures shallower so as to be more reticulate; without distinct depression anterior to level of inner angle of axilla; with white to brownish hairlike setae. Scutellum ( Fig. 14 ) usually with bright coppery mediolongitudinal band and progressively green to purple laterally, though sometimes medial band green with only limited coppery luster; sculpture sometimes aligned into variably distinct longitudinal setiferous furrows and slightly sinuous ridgelike interstices, or varying from punctate­coriaceous to extensively coriaceous with tiny setiferous pits, but with distinct, bare, mediolongitudinal coriaceous band slightly raised above height of other sculpture as low rounded ridge ( Fig. 37 ). Metanotum green to purple under different angles of light; dorsellum thick, with crenulate dorsal surface and coriaceous, bare, posterior surface; precrenular region of panel with 1 or 2 rows of setae (cf. Fig. 47 ). Acropleuron with slender, smooth and shiny subalar region separating punctate­alveolate prealar region from very finely coriaceous­aciculate or smooth and shiny postalar region; prealar region dark or with some greenish or violaceous to purple luster, subalar region dark or with coppery­greenish luster, and postalar region blue to purple or green. Lower mesepimeron punctate­reticulate. Metapleuron punctate­rugulose over distinct coriaceous to coriaceous­granular subsculpture, except for crenulate furrow along posterior margin and anterior margin ventrally. Propodeum dorsally green to blue or purple under different angles of light except plical region dark and vertical surface of callus more uniformly purple; paraspiracular region setose; callus smooth between setal pores dorsolaterally, but adjacent to metapleuron roughened, punctulate­coriaceous, similar to sculpture of metapleuron ( Fig. 52 ); plical region bare, with carinate margin of foramen ­like recurved to anterior margin of propodeum as strong median carina similar in appearance to crenulae lateral to median carina. Forewing hyaline; vannal area with subcubital setal line extending over about apical half. Legs entirely yellowish beyond coxae except metatibia usually broadly lighter, more yellowish white, medially.

Petiole composed of anterior carina and lunate horizontal surface obviously longer medially than propodeum, the surface longitudinally crenulate but crenulae either distinctly weaker or more widely spaced than on propodeal plical region (cf. Fig. 47 ). Gaster in dorsal view with penultimate tergum bright green to partly blue, contrasting distinctly in color with other dark brown terga, and in lateral view all terga except syntergum greenish dorsally to blue or purple ventrally; about twice as long as head and mesosoma combined. Syntergum about 0.75–0.85 x as long as remaining gaster and in lateral view about 8–9 x as long as high; uniformly setose, sculptured and tapered posteriorly, with cercus at or near basal margin.

MALE. Unknown

Biology. Unknown.

Discussion. Females of B. eximiassita differ from those of B. eximia only in comparatively minor color differences and one sculptural difference. Color pattern of the mesoscutum is the most conspicuous color difference, which results primarily from the shape of the notaular band posteriorly (cf. Figs. 13, 14 ). However, females of B. eximiassita also lack the distinct blue band from the parascrobal region lateral to the torulus, which characterizes B. eximia females (Fig. 1), they have the penultimate gastral tergum mostly bright green, and they usually have a distinct mediolongitudinal coppery band on the scutellum ( Fig. 14 ). The only significant sculptural difference is that in B. eximiassita the lateral surface of the callus is roughened ( Fig. 52 , cf. Fig. 43 ) similar to the metapleuron, whereas it is uniformly smooth and shiny in B. eximia ( Fig. 47 ). Balcha eximiassita is known from southeast Asia, whereas B. eximia currently is known only from Taiwan. Additional collecting from other areas may show the differences are variable and simply opposite extremes of intraspecific variation.

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.