The Wharton Lab

Opius peleus Fischer, 1970: 802–804. Holotype male in AEIC (examined).
Opius peleus: Marsh 1974: 287 (synonymy); Marsh 1979 : 210 (catalog); Wharton and Norrbom 2013: 16-18, 54-57 (key, diagnosis, distribution, host records).
Opius (Merotrachys) peleus: Fischer 1977: 655, 695–697 (key, redescription); Fischer 1979: 264 (key); Yu et al. 2005, 2012 (electronic catalogs).
Opius telephosi Fischer, 1970: 812–815. Synonymized by Marsh (1974: 287).

Fischer (1970, 1977) provides a detailed description and keys for this species, all in German. The above description is intended primarily to highlight features useful for separating O. peleus from the other species of Opius s. l. that have been reared from non-frugivorous Tephritidae. This species is readily distinguished from O. nympha , O. taramegillae , and members of the baderae, godfrayi, and pipitae species groups by the presence of extensive sculpturing on the propodeum. Opius yoderi , the only other species in this group with an extensively sculptured propodeum, has a densely furry mesoscutum.

Fischer (1977) placed O. peleus in the subgenus Merotrachys, which he defined in part by the presence of sculpture on the second metasomal tergum (T2). In the holotype, the striate sculpture on T2 is more distinct than in the specimens reared from Strauzia in Tennessee. Sculpture is variable in the Tennessee specimens, with some individuals exhibiting virtually no obvious sculpture while others are weakly striate or punctato-striate. In either case, the sculpture in O. peleus is distinctly different from that found in members of the ingenticornis species group, most of which have previously been included in Merotrachys (Wharton et al. 2013). Opius peleus also lacks the large pronope and complete dorsal carinae on the petiole (T1) characteristic of members of the ingenticornis group.

Holotype: Male, deposited in AEIC.

Opius peleus is very similar to O. antrimensis Fischer but the latter is only 0.5–0.7 x the size of O. peleus. Details of the facial sculpture, which Fischer (1977, 1979) emphasized as diagnostic for O. peleus in his keys, are difficult to discern in the holotype and only known specimen of O. antrimensis. The similarity between these two species suggests the possibility that O. antrimensis also attacks tephritids or other maggots feeding in roots or lower portions of stems.

Habitus (Fig. 1). Temple relatively broad (Figs 2-3), eye about 1.75–2.1 (female) and 1.35–1.6 (male) x longer than temple in lateral view, 1.1–1.3 x longer than temple in dorsal view. Clypeus (Figs 4-5) hemispherical, ventral margin weakly protruding in lateral view, sharp, truncate; mandibles deflected, labrum broadly exposed (Figs 3-4). Malar space (Fig. 3) almost as long as basal width of mandible, malar sulcus complete, deeply incised throughout. Mandible broadening basal-ventrally, but without distinctly delineated basal lobe or tooth (Fig. 3). Face variable in sculpture, minimally with strigose band along inner margin of eyes. Occipital carina absent dorsally, the gap less than distance between eyes in dorsal view, carina present and well developed laterally, widely separated from hypostomal carina at base of mandible (Fig. 6). Antenna with 43–47 (45 in holotype) flagellomeres, apical flagellomere long and conical. Pronotum dorsally narrow, with median pit; laterally with vertical carina adjacent median vertical groove usually present on ventral 0.3; crenulate along posterior margin, medially varying adjacent the margin from largely smooth to extensively rugulose (Fig. 3). Mesoscutum (Fig. 7) with deep, strongly sloping anterior declivity; notaulus a short, very deep impression barely extending posteriorly beyond anterior declivity; disc of mesoscutum largely bare, without midpit posteriorly; supramarginal carina absent, but base of notaulus rugulose (Fig. 7). Precoxal sulcus (Fig. 8) usually distinct as a broad, shallow, impression, short, not extending to anterior or posterior margins of mesopleuron, always unsculptured; mesopleural fovea crenulate along entire posterior margin of mesopleuron (Fig. 9). Propodeum rugulose throughout (Fig 10), short median carina sometimes distinct basally. Hind tibia without basal carina. Fore wing (Fig. 11) with stigma broad, wedge-shaped, relatively discrete distally, r arising from middle; 3RSa 1.3–1.45 x longer than 2RS; m-cu usually interstitial, varying from very weakly antefurcal to weakly postfurcal; 2CUb arising distinctly anteriorad middle of distal margin of 1st subdiscal cell (Fig. 11). Hind wing RS largely spectral, weakly pigmented basally; m-cu present as a spectral vein extending nearly to wing margin. T1 (Figs 10, 12, 13) with broad, deep laterope but without dorsope; dorsal carinae strongly elevated basally, converging to form a deep basal depression, absent posteriorly beyond spiracle; T1 rugose over posterior 0.5. T2 usually with trace of weakly rugulose sculpture (Fig. 14), sculpture sometimes not apparent (Figs 12-13). Ovipositor (total length) 1.4–1.5 x longer than mesosoma; ovipositor sheath 0.9 x length of mesosoma. Color : dark brown to black; mandible reddish yellow to yellow with apical teeth black; scape, pedicel, remaining mouthparts, legs, and usually T2, 3, 7, 8 yellow; wings hyaline.

Originally described from western South Carolina (USA). Additional specimens were reared from plant material collected relatively nearby in the Great Smoky Mountains National Park, Tennessee.

A series of specimens from Tennessee was reared from the tephritid Strauzia intermedia (Loew) collected from root mines of the asteracean Rudbeckia laciniata L. (Wharton and Norrbom 2013). These were reared on four consecutive years from the same locality.

Holotype label:

Wattacoo, Pickens Co., S. C.
V. 27. 61
G. F. Townes

This page was assembled largely by Bob Wharton and Andrew Ly. It is part of a revision of New World, mostly neotropical, opiines reared from non-frugivorous Tephritidae conducted by Wharton and Norrbom (2013). We are particularly grateful to Danielle Restuccia, Patricia Mullins, Trent Hawkins, Lauren Ward, and Gabriella Vasquez, who did all of the imaging and especially Danielle for preparing the plates. Gary Steck kindly sent all of the reared material of this species to the senior author for this study. Matt Yoder and Istvan Miko provided guidance on databasing issues associated with our use of mx and HAO respectively. We thank David Wahl (AEIC), Norm Penny and Bob Zuparko (CAS), Andrew Bennett and Henri Goulet (CNC), Max Fischer and Dominique Zimmermann (NHMW), and Paul Marsh and Robert Kula (Systematic Research Laboratory, USDA; USNM) for facilitating loans and general assistance associated with examination of holotypes and other material in their care. This work was supported largely by NSF DEB 0949027, with REU supplement 1313933 (to Wharton) and partly by NSF/PEET DEB 0328922 (also to Wharton). Page last updated January, 2014.

This material is based upon work supported by the National Science Foundation under Grant Numbers DEB 0949027 and DEB 0328922 with REU supplement 1313933.
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.