Sterictiphorinae species identification — Life in a Southern Forest

Image above courtesy of Kerry Stuart (iNaturalist observation) CC BY NC

Workbook

Note: This is a “work in progress”. Changes may be made as I discover additional relevant information.

Identification of species in subfamily Sterictiphorinae

The matrices below are designed to aid identification of all species in the 2 genera that comprise the Sterictiphorinae - Trichorhachus and Styphelarge.

Trichorhachus and Styphelarge share the following diagnostic features:

mid and hind tibiae with preapical spurs
antenna with 3 segments; scape and pedicel short; third segment long, bifurcated in male and ciliated, simple in female
fore wing with – petiolate anal cell; apex of radial cell separated from wing margin; 3 cubital cells

These genera differ in the following ways:

Styphelarge

hind basitarsus shorter than next 2 tarsal segments together
head and thorax with large coarse punctures
tongue when protruded shorter than length of head

Trichorhachus

hind basitarsus longer than next 2 tarsal segments together
head and thorax shining with at most sparse shallow punctures
tongue when protruded longer than length of head

Images from authoritative sources of selected species follow the matrices as a further aid.

Trichorhachus australis = Trichorhachus sobrinus

T. australis male - Westwood (1842) Pl.7, Fig.2

T. sobrinus male - Kirby (1882) Pl.iii, Fig.3

T. australis female, apex of abdomen - Benson (1938) Fig.10

T. australis, sawsheath from above - Benson (1938) Fig.8

Trichorhachus hyalinus

T. hyalinus male - Kirby (1882) Pl.iii, Fig.4

Trichorhachus nitidus

T. nitidus female - Kirby (1882) Pl.iii, Fig. 2

T. nitidus male with hind leg - Kirby (1882) Pl.iii, Fig.1

T. nitidus male head - Kirby (1882) Pl.iii, Fig.1a

T. nitidus male antenna - Morice (1919) Pl.13, Fig.3

T. nitidus female, apex of abdomen - Benson (1938) Fig.9

T. nitidus female, sawsheath from above - Benson (1938) Fig. 7

Styphelarge abdominalis

S. abdominalis male - Kirby (1882) Pl.iii, Fig.5

References:

Benson, R.B. 1938. Sawflies of the Subfamily Trichorhachinæ (Argidæ) (Hymenoptera, Symphyta), Annals and Magazine of Natural History, 2:8, 117-122.
Kirby, W.F. 1882. List of Hymenoptera, with descriptions and figures of the typical specimens in the British Museum. Vol. I. Tenthredinidae and Siricidae. London: British Museum, xxviii
Morice, F.D. 1919. Notes on Australian sawflies, especially the “Authors' Types” and other specimens in the British Museum of Natural History and the Hope Collections of the Oxford University Museum; with diagnostic synopses of the genera and species, and photographs illustrating their structural characters. Transactions of the Entomological Society of London 66: 247-333, pls XI-XV.
Westwood, J.O. 1841. Descriptions of some exotic species of sawflies. Arcana Entomologica p.23

This is a workbook page … a part of our website where we record the observations and references used in making species identifications. The notes will not necessarily be complete. They are a record for our own use, but we are happy to share this information with others.