The Wharton Lab

Opius matthaei Fischer, 1968: 77–78 (key); 90–92 (description). Holotype female in AEIC (examined).
Opius matthaei: Fischer 1971: 86 (catalog).
Opius (Merotrachys) matthaei: Fischer 1977: 655–656, 685–687 (key, redescription); Fischer 1979: 264 (key); Yu et al. 2005, 2012 (electronic catalogs).

This species is known only from the female holotype.

Face (Fig. 3) finely granular or coarsely shagreened throughout. Eye in lateral view (Fig. 4) 2.4–2.7 x longer than temple; temples in dorsal view not receding. Female antenna with 57 flagellomeres; setae on basal flagellomeres thin, pale. Mesoscutum anteriorly on nearly same plane as pronotum (Fig. 4), without distinct anterior declivity; notaulus (Fig. 5) extending laterally towards tegula as groove bordered by distinct supramarginal carina, base of notaulus weakly rugulose, thus appearing to extend to anterior margin of mesoscutum. Propodeum (Fig. 6) rugulose to finely granular with shallow median trough anteriorly, areola obscured by sculpture posteriorly. Fore wing (Fig. 9) with 3RSa weakly curved, 1.3 x longer than 2RS; m-cu interstitial to weakly antefurcal. T1 sharply declivitous anteriorly (Fig. 7), pit delimited posterior-medially; surface rugulose between dorsal carinae, shagreened laterally; dorsal carinae weakly sinuate, broadening subapically, narrowing apically (Fig. 8). T2 distinctly shagreened, T3 more weakly so, becoming smooth, polished laterally. Ovipositor short; ovipositor sheath about 0.3–0.4 x length of mesosoma. Color as in Figs 1, 2, 8: head, propodeum, T1, T4–T6 dark reddish brown to dark brown; mesosoma mottled dark orange to dark reddish brown; T2+T3 reddish brown; hind coxa and femur dark yellow; antenna without subapical pale ring; wing lightly infumate, nearly hyaline.

This is a relatively dark species (Figs 1, 2), most closely resembling O. albericus and O. pilosicornis in that regard, but the legs are more uniformly yellow in Opius matthaei (Fig. 2) In keys to species of the subgenus Merotrachys (Fischer 1977, 1979a), O. matthaei is widely separated from O. albericus and O. pilosicornis because of slight differences in the position of fore wing m-cu (antefurcal as in Fig. 9). Opius matthaei is most readily characterized by the densely granular facial sculpture (Fig. 3).

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 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, Campina Grande, near Curitiba

The data label attached to the holotype is shown in Fig. 1.

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 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.