The Wharton Lab

Opius (Merotrachys) albericus Fischer, 1979: 264–267 (key); 267–269 (description).
Holotype female in AEIC (examined).
Opius (Merotrachys) albericus: Yu et al. 2005, 2012 (electronic catalogs).

In the original description, the locality for one of the paratypes is listed as M. Crosso but the actual locality is M. Grosso. We have seen four additional male specimens from this same locality in Mato Grosso (CNC, TAMU) but we are unable to assign them to this species with complete confidence. There are slight differences in coloration (mid and hind coxae dark brown instead of white, for example) and the propodeum of one of these specimens is distinctly granular. In one of our specimens, m-cu is postfurcal in one fore wing and weakly antefurcal in the other.

Face (Fig. 3) distinctly punctate, punctures separated by about 1x their diameter, strongly shagreened adjacent eye margin, otherwise appearing very weakly shagreened to smooth between punctures, though difficult to see because of position on pin. Eye in lateral view about 2.0–2.5 x longer than temple; temples in dorsal view not receding (Fig. 4). Antenna of female broken, 42 flagellomeres remaining, male with 52 flagellomeres; setae on basal flagellomeres thick, dark. Mesoscutum anteriorly on nearly same plane as pronotum, without distinct anterior declivity; notaulus extending laterally towards tegula as groove bordered by distinct supramarginal carina. Propodeum (Figs 5, 6) coarsely rugose, median areola absent, median trough anteriorly difficult to see but apparently weak, indistinct. Fore wing (Fig. 1) with 3RSa straight, 1.4–1.5 x longer than 2RS; m-cu postfurcal. T1 (Figs 5-7) relatively long and narrow, declivitous anteriorly at about a 45 degree angle, basal pit delimited posterior-medially; surface shagreened throughout; dorsal carinae sinuate, widest subapically, narrowing apically, without obvious transverse carinae between dorsal carinae. T2 (Fig. 7) uniformly, distinctly shagreened; T3 mostly weakly shagreened, smoother and very finely punctate laterally. Ovipositor short, barely protruding; ovipositor sheath roughly 0.4 x length of mesosoma. Color as in Figs 1, 2: head, mesosoma, T1, T3–T6 dark reddish brown to dark brown; T2 white with narrow, dark brown lateral margins; hind coxa white; hind femur almost completely dark reddish brown; antenna without subapical pale ring; wing lightly infumate.

This species, described from western Brazil, is nearly identical to Opius pilosicornis , described from Peru. In the original description, Fischer (1979) separates the two species on the basis of quantitative differences in the shape of the head and T1, shape of the T1 dorsal carinae, and leg color. Slight differences in the shape of the head (width vs. length in dorsal view 1.8 in O. albericus , 2.0 in O. pilosicornis ) were the only features (of those listed in Fischer’s diagnosis) that we could confirm via side-by-side comparison of the two holotypes. Though the differences are subtle, we have chosen to accept the two as valid species pending collection and examination of more material to assess variation. Among the minor differences, the face appears to be more extensively shagreened in O. pilosicornis but more distinctly punctate in O. albericus and the metasoma is more densely setose posteriorly in O. albericus . These two species are most readily separated from other known species of the ingenticornis species group by the color pattern of white hind coxa, dark hind femur, and dark mesosoma (Fig. 2).

Additionally, as in all other members of the ingenticornis species group, this species can be further characterized as follows: Mandible short, broadly triangular, dorsal margin strongly angled ventrally, broadly exposing labrum. Clypeus shaped as a broad crescent, nearly hemispherical, flat to weakly protruding ventrally, ventral margin shallowly concave, rarely appearing truncate. Malar sulcus distinct, complete. Antenna unusually long, approximately twice longer than body; first flagellomere slender, longer than second, with long, narrow plate sensilla. Occipital carina broadly absent dorsally, the gap in dorsal view at least as wide as distance between eyes; carina well developed laterally and ventrally, widely separated from hypostomal carina ventrally. Pronope (Fig. 4) deep, wide, posterior margin at least weakly overlapping base of mesoscutum, thus obliterating posterior transverse sulcus medially; vertical carina absent on pronotum laterally. Mesoscutum without midpit; notaulus short, curved, pit-like anteriorly, narrowing and evanescent posteriorly. Propodeum with median depression at least anteriorly, never with median longitudinal carina. Mesopleuron without sternaulus, precoxal sulcus unsculptured, absent or very faintly indicated; hind margin of mesopleuron not obviously crenulate on dorsal 0.5. Fore wing 2CUb arising from or near middle of first subdiscal cell. Hind wing with RS distinctly infumate; m-cu absent. T1 with dorsal carinae parallel or nearly so, extending from base to apex; laterope large, deep; dorsope absent.

Brazil: Rondonia and Mato Grosso.

Labels attached to the holotype are shown in Figs 1-3.

Paratypes. One male, Brazil, Mato Grosso, Sinop, 12°31”S, 55°37W, x.1974, M. Alvarenga.

This page was assembled largely by Bob Wharton. It is part of a revision of the Opius ingenticornis species group conducted by Sophia Daniels, Xanthe Shirley, Danielle Restuccia and Bob Wharton, published by Wharton et al. (2013). We thank David Wahl (American Entomological Institute, Gainesville, FL) for loans and general assistance associated with examination of holotypes, as well as Max Fischer and Dominique Zimmermann (NHMW), Henri Goulet (CNC) and Paul Marsh (formerly USDA, Washington, D. C.) for facilitating other loans and work with material in their care. We are also sincerely grateful to Jim Woolley and Aaron Tarone for making available their imaging systems when ours crashed. Matt Yoder provided guidance on databasing issues associated with our use of mx. This work was supported in part by NSF DEB 0949027, with REU supplement 1213790. This work was conducted at Texas A&M University and was supported in part by NSF DEB 0949027, with REU supplement 1213790. Page last updated May, 2013.

This material is based upon work supported by the National Science Foundation under Grant Number DEB 0949027 and associated REU supplement 1213790.
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.