Acanthoperga species delineation
Image above courtesy of Karin Taylor (iNaturalist observation) CC-BY-NC-ND
Workbook
A review of iNaturalist observations of Acanthoperga sawflies to determine whether they can be confidently identified to species level using original descriptions in the literature
Matrix for 3 Acanthoperga spp. based on Westwood (1880), Benson (1939), Morice (1919), Rohwer (1910). Click to download a 63KB pdf version.
Summary:
A. leucomelas differs from both A. cameronii and A. marlatti in the following characters:
relative breadth/width of postocellar area - broader than long in A. leucomelas vs. longer than broad in A. cameronii, A. marlatti (Benson). However, Benson’s drawing of A. cameronii head (fig. 25) shows postocellar area being broader than long.
punctation of head in postocellar area - shining spaces between punctures in A. leucomelas vs. finely punctured without shining spaces in-between in A. cameronii and A. marlatti (Benson). However, Rohwer states that head of A. leucomelas is “dulled by small punctures”, which seems inconsistent.
colour of abdomen above - yellow in A. leucomelas vs. orange-brown in A. cameronii and A. marlatti (Benson). However, Rohwer describes the tergum as “bright reddish-yellow” rather than “yellow” and Westwood’s drawing of A. cameronii shows the dorsum of the abdomen being orange-brown.
infuscation of tip of forewings - not infuscate in A. leucomelas vs. infuscate in A. cameronii and A. marlatti (Benson).
Rohwer states that malar space in A. leucomelas is large, but unclear whether it is larger than in the other species. Benson compares the pedicel length in all 3 species to the length of the malar space, but does not state its absolute size (small vs. large).
Type specimens of P. leucomelas were collected from Kuranda and Cairns. Does this mean that the species is restricted to far north Queensland?
In summary, location, wing tip infuscation and possibly abdomen dorsum colour are the only differences between A. leucomelas and A. cameronii and A. marlatti which are consistent between different original descriptions.
Matrix of iNaturalist Acanthoperga observations. Click to download a 120KB pdf of the full matrix.
Photos of selected iNaturalist observations from above spreadsheet
References:
Benson, R.B. 1939. A revision of the Australian sawflies of the genus Perga Leach, sens. lat. (Hymenoptera, Symphyta). The Australian Zoologist 9: 324-357.
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.
Rohwer, S.A. 1910. Some Australian sawflies. Entomological News 21: 467-474
Westwood, J.O. 1880. A monograph of the sawflies composing the Australian genus Perga of Leach. Proceedings of the Zoological Society of London 1880: 359-379
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.