Rhogogaster

Globally, the genus Rhogogaster is thought to have 37 species distributed across the holarctic regions and the orient. Most are found in the palaearctic region. The Rhogogaster were split by Lacourt in 1997 to form the genus Cytisogaster. However, in genetic studies, Taeger in 2015 found the evidence to support this to be inconclusive having previously recommended that the Cytisogaster revert to a subgenus of Rhogogaster. Here Cytisogaster is treated as a subgenus. There are seven species in Britain and just one in Ireland.

Within the Tenthredininae, the Rhogogaster are difficult to separate from the genus Tenthredo and it is possible that this genus may be absorbed into the Tenthredo genus once further phylogenetic studies have been completed. The Rhogogaster are recognisable by their bright green and black body colour patterns, though there are one or two Tenthredo species with similar colouring. In the Rhogogaster, the third and fourth tooth of the right mandible are fused into a single truncate tooth, at least in females. In males this fused tooth may be bidentate. In frontal view the inner margins of the eyes converge but to a lesser extent than in the Tenthredo species such that the bottom of the eyes are not closer together than the width of the clypeus. On the forelegs, the tibial spurs are also blunt in most species.

The subgenus Cytisogaster can be recognised by the bicolorous stigma in the forewing.

The larvae are polyphagous.

Species list:

Rhogogaster (Cytisogaster) chambersi Benson, 1947

Rhogogaster (Cytisogaster) genistae Benson, 1947

Rhogogaster (Cytisogaster) picta (Klug, 1817)

Rhogogaster (Rhogogaster) chlorosoma (Benson, 1943)

Rhogogaster (Rhogogaster) punctulata (Klug, 1817)

Rhogogaster scalaris (Klug, 1817) = Rhogogaster viridis (Linnaeus, 1758)

Rhogogaster viridis (Linnaeus, 1758) = Rhogogaster dryas (Benson, 1943)

References:

Benson, R. B. 1947: A new British sawfly (Hym., Tenthredinidae) related to Rhogogaster picta (Klug). - The Entomologist's Monthly Magazine, Fourth Series, London 83(8): 96-99

Benson, R. B. 1949: Rhogogaster genistae (Benson), a new British sawfly (Hym., Tenthredinidae). - The Entomologist's Monthly Magazine, Fourth Series, London 85(10): 286-287

Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London

Benson, R. B. 1965: The classification of Rhogogaster Konow (Hymenoptera: Tenthredinidae). - (The) Proceedings of the Royal Entomological Society of London. Series B: Taxonomy, London 34: 105-112

Chambers, V. H. 1950: The larvae of the Broom Sawflies Rhogogaster picta Klug and R. genistae Benson (Hym., Tenthredinidae). - The Entomologist's Monthly Magazine, Fourth Series, London 86(11): 117-120

Chambers, V. H. 1951: The larva and foodplant of Rhogogaster chambersi Benson (Hym., Tenthredinidae). - The Entomologist's Monthly Magazine, Fourth Series, London 87(12): 202-205

Chambers, V. H. 1952: A postscript upon Rhogogaster (Hym., Tenthredinidae). - The Entomologist's Monthly Magazine, Fourth Series, London 88(13): 62

Goulet, H., 1996. Revision of the nearctic species of the Arcuata group of the genus Tenthredo with notes on the higher classification of the Tenthredinini (Hymenoptera: Symphyta, Tenthredinidae). Contributions of the American Entomological Institute.

Lacourt, J. 1997: Contribution à une révision mondiale de la sous-famille des Tenthredininae (Hymenoptera: Tenthredinidae). - Annales de la Société Entomologique de France (N. S.), Paris 32[1996](4): 363-402

Liston A, Knight G, Sheppard D, Broad G, Livermore L (2014) Checklist of British and Irish Hymenoptera - Sawflies, ‘Symphyta’. Biodiversity Data Journal 2: e1168. https://doi.org/10.3897/BDJ.2.e1168

Ross, H. H. 1943: The Nearctic species of the genus Rhogogaster (Hymenoptera). - The Pan-Pacific Entomologist, San Francisco 19 (4): 129-133

Taeger, A. 1991: Zwei neue paläarktische Blattwespengattungen aus der Unterfamilie Tenthredininae (Insecta, Hymenoptera, Symphyta: Tenthredinidae). - Entomologische Abhandlungen Aus dem Staatliches Museum für Tierkunde in Dresden , Dresden 54 (3): 71-95

Taeger, A.; Viitasaari, M. 2015: European Rhogogaster s. str., with notes on several Asian species (Hymenoptera: Tenthredinidae) - Zootaxa, Auckland 4013(3): 369-398.

Taeger, A., Liston, A.D., Prous, M., Groll, E.K., Gehroldt, T. & Blank S.M. 2018: ECatSym – Electronic World Catalog of Symphyta (Insecta, Hymenoptera). Program version 5.0 (19 Dec 2018), data version 40 (23 Sep 2018). – Senckenberg Deutsches Entomologisches Institut (SDEI), Müncheberg. https://sdei.de/ecatsym/ Access: 19 Dec 2020

Zombori, L. 1982: The European genera of Tenthredininae (Hymenoptera: Symphyta, Tenthredinidae). - Acta Zoologica Academiae Scientiarum Hungaricae, Budapest 28(3-4): 455-460