Ovipositing female of Macroglenes penetrans, from Saskatoon Research Centre.

Belongs within: Chalcidoidea.
Contains: Gastrancistrus.

The Pireninae are a group of wasps parasitic on midges of the Cecidomyiidae (Bouček 1988). In the case of Macroglenes, the preferred hosts are on grasses, and this genus has been widely introduced as a biological control for cereal pests.

The Pireninae
Published 20 December 2020

The chalcidoid wasps are truly a remarkable array: tiny wonders coming in a bewildering variety of forms. For this post, I’m looking at the members of the chalcidoid subfamily Pireninae.

Macroglenes sp., copyright Charley Eiseman.

The Pireninae are currently recognised as one of the subfamilies of the Pteromalidae, a chalcidoid ‘family’ that is long overdue for reclassification as phylogenetic studies have agreed that it is extensively polyphyletic* (e.g. Heraty et al. 2013). The pirenines are very small wasps, about one to two millimetres in length. They’ve always struck me as having a fairly fly-like habitus: they lack the metallic coloration and strong sculpturing of many other pteromalids, often being uniformly black or yellow, and carry upright bristle-like setae on the head and mesosoma. Characteristic features of the Pireninae also include antennae inserted low on the face, reduced numbers of antennal segments (and hence often rather short antennae), a large clypeus that often protrudes ventrally, and a dorsally rounded mesosoma often with deeply impressed notauli (longitudinal grooves on the mesoscutum) (Bouček 1988). About ten genera are currently recognised in the subfamily. Perhaps the most remarkable is the genus Zebe, named by John La Salle in 2005 from a single female that he says, at the time, had stymied multiple hymenopterists as to what it might be for two decades. Zebe has legs with four-segmented tarsi, instead of the five-segmented tarsi of other pteromalids, and the female has a long horn extending forward from the mesoscutum and hanging over the head. As in other micro-wasps with comparable structures, this horn probably provides space for the retraction of an extraordinarily long ovipositor.

*But just in case anyone who stands to have some influence is reading, I will point out that the number of subfamilies that need to excised from the Pteromalidae could be kept to a minimum if the family is expanded to include the Ormyridae, Torymidae, Eucharitidae and Perilampidae. Bonus points that these are the families that are the hardest to distinguish from pteromalids to begin with.

Female Zebe cornutus, from Mitroiu (2011).

The life habits of most pirenines are very little known. Those whose hosts are known develop as parasites of Cecidomyiidae, gall midges, and may be found in association with the galls produced by those flies on various plants. Species of the genus Macrogelenes attack cecidomyiids associated with grasses, and some have been investigated as control agents for midges on commercial crops. So these tiny little wasps could prove themselves very valuable to humans.

Systematics of Pirenidae
<==Pirenidae [Eriaporidae]
    |    |--Promuscidea Girault 1917G17a (see below for synonymy)
    |    |    |--*P. unfasciativentris Girault 1917G17a [incl. *Mesopirene fasciativentrisB88]
    |    |    |--*Eurymyiocnema’ aphelinoidesH83
    |    |    |--P. comperellaHB13
    |    |    `--P. laticeps [=*Eriaporus laticeps]H83
    |    `--Eunotiscus Compere 1928BM22, H83
    |         `--*E. gahaniH83
    |    |--Euryischia Riley 1889H83
    |    |    |--*E. lestophoniH83
    |    |    |--E. melancholica Girault 1913GM79
    |    |    |--E. psyllae Girault 1930G30
    |    |    |--E. sumneri Girault 1913GM79
    |    |    `--E. vertexalis Girault 1930G30
    |    |--Euryischomyia Girault 1914MH11, GM79
    |    |    `--*E. washingtoniH83
    |    `--Myiocnema Ashmead 1900BM22, H83
    |         `--*M. compereiH83
    |--Cecidellis Hanson 2005 [Cecidellinae]BM22
    |--Pireninae [Pireniani, Pirenina, Pireninae, Pirenini]B88
    |    |--Velepirene Bouček 1988B88
    |    |    `--*V. gressitti Bouček 1988B88
    |    |--Parasyntomocera Girault 1917G17b
    |    |    `--*P. hillmeadia Girault 1917G17b
    |    |--Amuscidea Girault 1913 [incl. Erotolepsiopus Girault 1915]B88
    |    |    |--*A. nigripes Girault 1913B88
    |    |    `--A. subsolana (Girault 1915) [=*Erotolepsiopus subsolanus]B88
    |    |--Zebe La Salle 2005LS05
    |    |    `--*Z. cornutus La Salle 2005LS05
    |    |--Petipirene Bouček 1988MH11, B88
    |    |    `--*P. eximia Bouček 1988B88
    |    |--Macroglenes Westwood 1832MH11, B88 (see below for synonymy)
    |    |    |--*M. oculatusB88
    |    |    |--M. clypeatus (Girault 1925) [=Phocion clypeatus]B88
    |    |    |--M. congener (Girault 1925) [=Phocion congener]B88
    |    |    |--M. gramineusHB13
    |    |    |--M. ipswichi (Girault 1925) [=*Phocion ipswichi, Pirene ipswichi]B88
    |    |    |--M. penetransB88
    |    |    `--M. varicornisBM22 [=*Pirene varicornisB88]
    |    |--EcrizotomorphaBM22
    |    |--KeesiaBM22
    |    |--LasalleaBM22
    |    |--PapuaglenesBM22
    |    `--WatshamiaBM22
    `--Tridyminae [Tridymina, Trydymini]BM22
         |--Epiterobia Girault 1914BM22, B88 [incl. Neroptrocerus Girault 1915B88]
         |    |--*E. reticulatithorax Girault 1914B88
         |    |--E. sanguinipes Girault 1938B88
         |    `--E. subatra (Girault 1915) [=*Neroptrocerus subater]B88
         |--Premiscogaster Girault 1933BM22, B88
         |    |--*P. australia (Girault 1917) [=Miscogaster australia]B88
         |    `--P. punctatifascies (Girault 1922) [=Schizonotus punctatifascies, S. punctatifacies]B88
         |--Sirovena Bouček 1988BM22, B88
         |    |--*S. stigma Bouček 1988B88
         |    `--S. costallifera Li, Xiao & Huang 2013LXH13

Macroglenes Westwood 1832MH11, B88 [incl. Corynocere Nees 1834B88, Phocion Girault 1925B88, Pirene Haliday 1833B88, Pirenisca Ghesquière 1946B88]

Promuscidea Girault 1917G17a [incl. Eriaporus Waterston 1917H83, Eurymyiocnema Compere 1947H83, Mesopirene Girault 1919B88]

*Type species of generic name indicated


[B88] Bouček, Z. 1988. Australasian Chalcidoidea (Hymenoptera): A biosystematic revision of genera of fourteen families, with a reclassification of species. CAB International: Wallingford (UK).

[BM22] Burks, R., M.-D. Mitroiu, L. Fusu, J. M. Heraty, P. Janšta, S. Heydon, N. D.-S. Papilloud, R. S. Peters, E. V. Tselikh, J. B. Woolley, S. van Noort, H. Baur, A. Cruaud, C. Darling, M. Haas, P. Hanson, L. Krogmann & J.-Y. Rasplus. 2022. From hell’s heart I stab at thee! A determined approach towards a monophyletic Pteromalidae and reclassification of Chalcidoidea (Hymenoptera). Journal of Hymenoptera Research 94: 13–88.

[G17a] Girault, A. A. 1917a. New Javanese Hymenoptera. Privately published (reprinted: Gordh, G., A. S. Menke, E. C. Dahms & J. C. Hall. 1979. The privately printed papers of A. A. Girault. Memoirs of the American Entomological Institute 28: 59–71).

[G17b] Girault, A. A. 1917b. Chalcidoidea nova Marilandensis. II. Privately published (reprinted: Gordh, G., A. S. Menke, E. C. Dahms & J. C. Hall. 1979. The privately printed papers of A. A. Girault. Memoirs of the American Entomological Institute 28: 114–115).

[G30] Girault, A. A. 1930. New pests from Australia. IX. Privately published (reprinted: Gordh, G., A. S. Menke, E. C. Dahms & J. C. Hall. 1979. The privately printed papers of A. A. Girault. Memoirs of the American Entomological Institute 28: 278–279).

[GM79] Gordh, G., A. S. Menke, E. C. Dahms & J. C. Hall. 1979. The privately printed papers of A. A. Girault. Memoirs of the American Entomological Institute 28: 1–400.

[H83] Hayat, M. 1983. The genera of Aphelinidae (Hymenoptera) of the world. Systematic Entomology 8: 63–102.

[HB13] Heraty, J. M., R. A. Burks, A. Cruaud, G. A. P. Gibson, J. Liljeblad, J. Munro, J.-Y. Rasplus, G. Delvare, P. Janšta, A. Gumovsky, J. Huber, J. B. Woolley, L. Krogmann, S. Heydon, A. Polaszek, S. Schmidt, D. C. Darling, M. W. Gates, J. Mottern, E. Murray, A. D. Molin, S. Triapitsyn, H. Baur, J. D. Pinto, S. van Noort, J. George & M. Yoder. 2013. A phylogenetic analysis of the megadiverse Chalcidoidea (Hymenoptera). Cladistics 29: 466–542.

[LS05] La Salle, J. 2005. Zebe cornutus gen. et sp. nov., a new Pireninae (Hymenoptera: Pteromalidae) with 4-segmented tarsi and a mesoscutal horn. Acta Societatis Zoologicae Bohemoslovenicae 69: 193–197.

[LXH13] Li, Z., H. Xiao & D.-W. Huang. 2013. Sirovena Bouček (Pteromalidae: Pireninae), a new member of the fig wasp community associated with Ficus microcarpa (Moraceae). Zootaxa 3619 (5): 581–588.

[MH11] Munro, J. B., J. M. Heraty, R. A. Burks, D. Hawks, J. Mottern, A. Cruaud, J.-Y. Rasplus & P. Jansta. 2011. A molecular phylogeny of the Chalcidoidea (Hymenoptera). PloS One 6 (11): e27023.

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