Heterarthrus imbrosensis Schedl, 1981

Liston, Andrew D., Jacobs, Hans-Joachim & Prous, Marko, 2015, The Sawflies of Crete (Hymenoptera, Symphyta), Deutsche Entomologische Zeitschrift 62 (1), pp. 65-79 : 65

Taxon classification Animalia Hymenoptera Tenthredinidae

† Heterarthrus imbrosensis Schedl, 1981

Material.

Crete; 5♀♀, 7♂♂, Omalos, 25.iv.2013, swept from Acer sempervirens : the host ( Schedl 1981).

Barcode data.

the barcode of one specimen collected from Acer sempervirens from the Peloponnese and determined as Heterarthrus wuestneii (Konow, 1905) (DEIGISHym11102), diverges by 0.7% from two Lower Austrian specimens of Heterarthrus wuestneii (BC ZSM HYM 04121, 04122). The minimum barcode divergence of the two barcoded Cretan Heterarthrus imbrosensis (DEIGISHym20655, 20656) from the Peleponnesian Heterarthrus wuestneii specimen is 1.8%.

Morphologically.

Heterarthrus imbrosensis closely resembles Heterarthrus wuestneii . Specimens from Crete are darker than Central European (German and Austrian) Heterarthrus wuestneii . The face may be entirely black in Cretan females, but usually there are at least small white patches on the inner orbits, whilst the tegula varies from entirely black to black with the posterior edge white. The Heterarthrus wuestneii specimens from the Peloponnese are intermediate in coloration. According to Schedl (1981), Heterarthrus imbrosensis is distinguished from similar species of the aceris group by the shape of the head behind the eyes in dorsal view. No such difference was found between the specimens of Heterarthrus wuestneii and Heterarthrus imbrosensis available to the authors. Furthermore, the apparently apically widened sawsheath of the holotype of Heterarthrus imbrosensis [examined] as drawn by Schedl (1981) is the result of disruption of the valves of the sheath during extraction of the saw. As pointed out by Leppänen et al. (2012), the status of some of the Acer -feeding Heterarthrus needs further study, ideally including sequencing of nuclear DNA.