The Wharton Lab

Pion Schiodte, 1839: 318.
Type species: Mesoleptus fortipes Gravenhorst, 1829. Subsequent designation by Viereck (1914: 117).

Catoglyptus Foerster, 1855: based on Holmgren (1857: 106).
Type species: Mesoleptus fortipes Gravenhorst, 1829. Designated by Viereck (1912: 175).

Earlier authors used 1838 as the date of publication of Schiodte’s work. Horstmann (2004) presents evidence for the 1839 date of publication. Horstmann (2004) also notes that Schiodte indicated two species in his publication: the one previously described by Gravenhorst and a second one that Schiodte described as a new species. Previously, several authors had indicated that the genus was monobasic.

“Holmgren, 1855” is sometimes given as the authority for Catoglyptus. Yu et al. (2012) cite Carlson (1979: 264) for correction of the date of publication of Holmgren’s work, though that page only lists the date change and not the basis for the change. Holmgren (1857) gave credit for the genus name to “Foerster, 1855.”

The following valid species were included by Yu et al. (2012).

Pion fortipes (Gravenhorst, 1829)
Pion nigripes Schiodte, 1839
Pion interstitialis Constantineanu and Constantineanu, 1970
Pion qinyuanensis Chen, Sheng & Miao, 1998
Pion stammeri (Bauer, 1958)
Pion schenkii (Jaennicke, 1867)
Pion yifengensis Sheng, 2011

Pion crassipes (Holmgren, 1857) was treated as a junior synonym of Pion nigripes Schiodte, 1839 by Horstmann (2004).

Pion is readily recognized by the combination of the absence of a glymma on the stalk-like T1, the lack of a basal, transverse depression on the outer face of the mandible, the u-shaped grooves between the propodeum and metanotum, and the distinctive clypeus. The longer, narrower mandibles and distinct apical impression of the clypeus, with its sharp margin, separate Pion from the somewhat similar Syntactus.

Clypeus uniformly setose with deep, widely spaced punctations (Fig. 4); ventral margin strongly impressed, truncate medially, the margin thin and sharp (Fig. 3), with rounded, transverse ridge subapically (Fig. 3); epistomal sulcus impressed throughout, weaker medially; clypeus in profile weakly protruding (Fig. 4). Face setose, densely punctate but not granular; frons and vertex more finely punctate, uniformly setose; inner eye margins parallel to very weakly converging. Malar space short but distinct, distinctly less than half basal width of mandible; malar sulcus absent. Mandible long, parallel-sided; dorsal tooth distinctly narrower and shorter than ventral tooth (Figs 3, 5); basal, transverse impression absent. Maxillary palp a little shorter than height of head; antenna shorter than body in both sexes. Hypostomal carina meeting occipital carina distinctly dorsad base of mandible; occipital carina complete. Epicnemial carina reaching anterior margin of mesopleuron or nearly so (Fig. 1). Notaulus varying from absent to present as a broad, weak depression, barely indicated dorsally, not reaching level of tegula. Groove between propodeum and metapleuron broadly u-shaped, readily visible in lateral view; broad, u-shaped groove mid-dorsally between propodeum and metanotum also readily visible in lateral view; pleural carina well-developed, complete; median and lateral longitudinal carinae well developed as is posterior transverse carina; anterior transverse carina absent, thus areola not closed anteriorly. Hind femur stout; apical margin of mid tibia not expanded into a distinct tooth similar to that of fore leg; apical comb on posterior side of hind tibia absent; posterior hind tibial spur about 5-6x longer than maximum width at base, hind tibial spurs almost equal in length; tarsal claws large, not pectinate. Fore wing areolet absent; stigma narrow, Rs+2r arising near basal third of stigma. Hind wing with first abscissa of CU1 varying from equal in length to or longer than 1cu-a. T1 (Fig. 6) long, slender, parallel-sided from base to distinctly posteriorad spiracles, then abruptly expanding; weakly decurved in profile; dorsal carinae extending full length of parallel-sided portion, fading into and largely absent from expanded posterior portion; basal depression at dorsal tendon attachment small; dorsal-lateral carina complete between spiracle and apex of T1; glymma absent. S1 extending full length of parallel-sided portion, distinctly posteriorad spiracle. T2 thyridium absent; laterotergites of T2 and T3 separated by creases from median tergite. Ovipositor (Fig. 7) weakly upcurved; ovipositor sheath more distinctly upcurved; ovipositor distinctly protruding (as in many other pionines), slender throughout though not exceptionally so; without dorsal, subapical notch.

This description is expanded from that given by Townes (1970), who also included it in a key to genera of Pionini.

Described species are known from Europe, Russia, and China. Townes (1970) mentioned an undescribed species from Japan.

The follwoing hosts and references are from Yu et al. (2005)..

Arge rustica (Hinz 1961)
Dolichovespula maculata (Graham 1965)
Gilpinia pallida (Forsius 1911; Kangas 1941)
Macrophya albicincta (Weiffenbach 1988; Hinz 1961, 1991)
Macrophya alboannulata (Hinz 1991)
Macrophya crassula (Hinz 1991)
Macrophya ribis (Hinz 1991)
Rhogogaster punctulata (Brischke 1871)
Tenthredo livida (Hinz 1961, 1991)
Tenthredo rubricoxis (Hinz 1961, 1991)
Tenthredopsis excisa (Hinz 1961)
Tenthredopsis litterata (Aubert 2000)
Tenthredopsis nassata (Hinz 1961)

This page was assembled by Bob Wharton as part of a larger collaborative effort on the genera of Ctenopelmatinae.

This work would not have been possible without the groundwork provided by Ian Gauld’s study of the Australian and Costa Rican faunas, and we are particularly grateful for his assistance in many aspects of this study. We also thank David Wahl of the American Entomological Institute and Andy Bennett of the Canadian National Collection for extended loans of the material used for this study and particularly Dave Karlsson for sending valuable material from the Swedish Malaise Trap Survey (Trap 22, collection event 1638). Matt Yoder provided considerable assistance with databasing issues, and our use of PURLs (http://purl.oclc.org) in this regard follows the example of their use in publications by Norm Johnson. Heather Cummins, Andrea Walker, Patricia Mullins, Caitlin Nessner, Amanda Ladigo, and Cheryl Hyde graciously assisted with image processing, formatting, and literature retrieval. This study was supported by the National Science Foundation’s PEET program under Grant No. DEB 0328922 and associated REU supplement #s DEB 0723663, 0923134, and 1026618. Page last updated Jan, 2015.

This material is based upon work supported by the National Science Foundation under Grant Number DEB 0328922 with REU supplements DEB 0723663, 0923134, and 1026618. 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.

This material is based upon work supported by the National Science Foundation under Grant Number DEB 0328922 with REU supplements DEB 0723663, 0923134, and 1026618. 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.