The Wharton Lab

Opius pipitae Wharton, 2013 ZooKeys 349: 16-19, 58-61.

Color is somewhat variable in the type series. Some of the color differences are natural, but others are due to postmortem changes. There is natural variation in the degree of weak infumation on the propleuron and the presence of a faint median dark line of the mesoscutum. Postmortem changes include subcuticular darkening in some specimens and metasomal pale patches darkening from white to yellow.

Holotype: Female, deposited in UNAM.

The species in the Opius pipitae species group are similar to members of the baderae and godfrayi species groups in general appearance, reduced propodeal sculpture, absence of a midpit on the mesoscutum, absence of sculpture within the precoxal sulcus, and the notably anterior position of 2CUb along the distal margin of the 1st subdiscal cell. As in members of the godfrayi species group, the labrum is exposed in the gap between the ventral margin of the clypeus and the dorsal margin of the mandibles when the latter are closed. Unlike members of the godfrayi species group, however, the occipital and hypostomal carinae are widely separated ventrally, a characteristic of members of the baderae species group (and most other Opius s.l.).

Three species are included in the Opius pipitae species group: O. pipitae, O. stecki , and O. townesi. These species will key to either Pendopius or Opiothorax in the subgeneric classification of Fischer (1972, 1977) and to Adontopius Fischer in Fischer (1999). In Li et al. (2013), they key to Phaedrotoma. In members of the pipitae species group, the vertical carina on the pronotum laterally is very well developed and the pleural sulcus is distinct both anterior and posterior to the propodeal spiracle.

Opius pipitae is much lighter in color than O. stecki . The mesosoma is completely dark in the latter species. The pronotum laterally also has a little more sculpture medially in O. pipitae than in O. stecki . Opius pipitae is very similar to O. townesi, a previously described species for which no host information is available. Opius townesi is smaller, with significantly fewer flagellomeres (30), is slightly darker, without the pale orbital ring dorsally, and T1 is not as heavily sculptured. Although Fischer (1977) placed O. townesi in the subgenus Opius, the labrum is exposed in the small but distinct gap between the ventral margin of the clypeus and the dorsal margin of the mandibles. Opius townesi is therefore included in the pipitae species group as defined here. Opius townesi was described from Maryland (USA).

Habitus (Fig. 1). Eyes in dorsal view (Fig. 2) very slightly bulging beyond temples, temples weakly but distinctly receding. Clypeus (Fig. 4) 1.7–1.9 x wider than high, weakly punctate, more deeply and densely so along ventral margin; nearly hemispherical in outline with epistomal sulcus almost evenly rounded, slightly more triangular in outline in female; somewhat bulging in profile (Fig. 3), slightly protruding ventrally; ventral margin weakly convex in anterior view with dorsal margin of mandible weakly curved, mandibles weakly deflected, exposing part of labrum; base of mandible not expanded ventrally to form a basal tooth or lobe (Fig. 4). Malar sulcus distinctly impressed throughout, deeper near eye (Figs 3, 4). Antenna with 38–40 flagellomeres. Mesosoma 1.35–1.4 x longer than high. Pronotum laterally (Fig. 3) with vertical groove usually crenulate to rugulose dorsally and ventrally, weakly wrinkled medially posteriorad distinct vertical carina, carina weaker, evanescent dorsally and ventrally. Notaulus (Fig. 2) a short groove weakening posteriorly, extending nearly to level of anterior margin of tegula, widely separated from anterior margin, not margined anteriorly by carinae. Propodeum unsculptured, with a few weak carinulae along posterior margin (Fig. 5). Fore wing 3RSa 1.25–1.4 x longer than 2RS; (RS+M)a usually weakly sinuate (Fig. 1). T1 (Figs 5-6) 1.85–2.2 x wider at apex than at base, length 0.9–1.0 x apical width; smooth, unsculptured basally, striate to strigose over apical 0.6–0.7, more densely sculptured apical-medially; dorsal carina distinct, elevated basally, extending to apex but largely obscured by sculpture posteriorly, indicated primarily as lateral margin of very weakly elevated median area. Ovipositor (total length) 1.3 x longer than mesosoma; ovipositor sheath 0.8 x length of mesosoma (Fig. 8). Color (Figs 1-7): Head similar in general color pattern to that of O. nablus but dark facial spot sometimes (20%) more diffuse and not extending ventrally to epistomal sulcus; pale orbital ring in two specimens almost interrupted near torulus by traces of dark band extending to eye from dark patch on frons. Mesosoma black to dark red-brown except propleuron at least ventral-laterally, anterior declivity of mesoscutum near notaulus, subalar elevation, tegula and basal wing sclerite white to very pale yellow; most of mesoscutum, axilla, mesopleuron ventrally, and small spot on mesopleuron immediately dorsad mid coxa yellow; meso- and metanotum laterally, especially adjacent wing bases, varying from yellow to light brown, mesoscutum medially with narrow, faint to distinct dark median line in nearly all specimens. Metasomal terga dark reddish brown to black, with posterior margins of T3–T6 broadly white to hyaline and anterior margins of T4–T6 with broad white band medially; T7 white. Fore and mid tibiae and all femora pale yellow; hind tibia brown with basal 0.2 dark brown. Body length 3.3–3.9 mm; wing length 4.15–4.55 mm; mesosoma length 1.35–1.55 mm.

Type locality: Mexico, Morelos, Huitzilac. Some of the paratypes were collected from nearby localities in Morelos: 2 km W of Huitzilac and ridge above Sto. Domingo Ocotitlan.

All specimens of O. pipitae were reared from stem galls formed by an undescribed species in what may be an undescribed genus of Tephritidae attacking the asteracean Montanoa frutescens. Parasitoids were reared from carefully isolated hosts and some members of the type series are pinned with the host remains (Fig. 1). Rate of parasitization by O. pipitae was 50, 62.5, and 100% from the three sample sites, though overall the numbers were low with only 4 flies and 9 wasps reared.

One specimen of O. gabriellae was reared from a species of Neotephritis infesting flower heads of his same host plant.

Holotype labels:

MEXICO: Morelos
Huitzilac, 22.IX.
1991, A.L.Norrbom

Second label:
reared ex. lateral
stem gall on Montanoa
frutescens (91M5A)

Third label:
ex. Tephritidae
n. gen., n. sp.

The date on the holotype label and one of the female paratypes was incorrectly given as 22.X in the original description of this species. The correct date is 22.IX

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 Bob Wharton (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. Paul Marsh initially made much of this material available to the senior author. 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 RW) and partly by NSF/PEET DEB 0328922 (also to RW). Page last updated October, 2013.

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.