Genus Strongylogaster

Strongylogaster

There are thought to be around 60 species of Strongylogaster distributed across the holarctic and neotropical regions. There are five species in Britain and three in Ireland (macula, mixta, and multifasciata).

Characteristics within the Strongylogaster vary from species to species leading some authors to suggest splitting the genus into several genera. However, current thinking is that there are seven species groups within the one genus (Naito, 1996). Even within these groups, characteristics are variable. Strongylogaster can be described using the following characteristics. The antennae are filiform with the antennal pedicel is discoid being wider than long. The first and second flagellomeres are subequal in length. There is a post-genal carina. The prepectus is present as a narrow, raised shoulder that is separated from the mesepisternum by a furrow rather than a suture. The anal cell of the forewing may have a cross vein either present or absent and in the hindwing the anal cell may be sessile, or have a short petiole. The tarsal claws lack a basal lobe but may be simple or have a small or large inner tooth.

The division of the genus into species groups is achieved primarily from the shape of the female sawsheath. Differences in the shape of the clypeus, the frontal area, the anal cells of both the fore and hindwing, the tarsal claw and the lancet are also useful in separating the species groups. The species groups are as follows: filicis group, macula group, multifasciata group, mixta group, osmundae group, remota group, and tacita group.

Larvae of the Strongylogaster feed on the fronds of ferns.

Species list:

Strongylogaster filicis (Klug, 1817)

Strongylogaster macula (Klug, 1817)

Strongylogaster mixta (Klug, 1817)

Strongylogaster multifasciata (Geoffroy, 1785)

Strongylogaster xanthocera (Stephens, 1835)

References:

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

Blank, S.M., Taeger, A. and Naito, T., 1999. Case 3064 Strongylogaster Dahlbom, 1835 (Insecta, Hymenoptera): proposed conservation by the designation of Tenthredo multifasciata Geoffroy in Fourcroy, 1785 as the type species. Bulletin of Zoological Nomenclature, 56(1), p.23.

Blank, S. M. 2002: Taxonomic Notes on Strongylogasterini (Hymenoptera: Tenthredinidae). - Proceedings of the entomological Society of Washington, Washington 104(3): 692-701.

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

Muche, W. H. 1969: Die Blattwespen Deutschlands. II. Selandriinae (Hymenoptera). - Entomologische Abhandlungen. Staatliches Museum für Tierkunde in Dresden , Leipzig 36 [Supplement][1967/1970]: 61-96

Naito, T. 1996: Phylogeny of the fern associated sawfly genus Strongylogaster Dahlbom (Hymenoptera: Tenthredinidae). - Memoirs of the Entomological Society of Washington., Washington 17: 161-178

Smith, D. R. 1969: Nearctic Sawflies. II. Selandriinae: Adults (Hymenoptera: Tenthredinidae). - Technical Bulletin, U.S. Department of Agriculture, Washington 1398: 1-48

Vasu, V. & Saini, M. S. 1999: Taxonomy of the genus Strongylogaster Dahlbom from India (Hymenoptera: Symphyta: Tenthredinidae: Selandriinae). - The Raffles Bulletin of Zoology, Singapore 47(1): 185-192

Zombori, L. 1981: The European genera of Selandriinae and Dolerinae (Hymenoptera: Symphyta, Tenthredinidae). - Acta Zoologica Academiae Scientiarum Hungaricae, Budapest 27(3-4): 443-450