Phyllocolpa alienata (FÖRSTER, 1854)

Liston, A. D., Knight, G. T., Heibo, E., Bland, K. P., Barstad, Trond Elling, Blank, S. M., Boeve, J. - L., Fiedler, K., Grearson, K. J., Halstead, A., Jacobs, H. - J., Jansen, E., Lonnve, O., Prous, M., Robinson, J. & Taeger, A., 2012, On Scottish sawflies, with results of the 14 International Sawfly Workshop, in the southern Highlands, 2010 (Hymenoptera, Symphyta), Beiträge Zur Entomologie = Contributions to Entomology 62, pp. 1-68 : 43

Phyllocolpa alienata (FÖRSTER, 1854)

We unfortunately kept no record of the Salix species from which P. alienata was swept. According to Kopelke (2007b) it is monophagous on Salix aurita , one of the more abundant Salix species on and below the crags of M. n. T.

As illustrated by Benson (1958: as Pontania coriacea ), the saw in its entirety has a very distinctive form, being almost sickle-shaped, with the radix very long. This contrasts strongly with the comparitively short radix and straighter, less strongly tapered form of the saws of all other British species except for P. leucapsis sensu Kopelke. A deficit in the illustrations by Kopelke (2007a, b) is that only a part of the radix is shown, although the total shape of this and the detailed structure of the base seem to be extremely helpful in identifying many species of Nematinae , including this taxon. Kopelke (2007b) designated a neotype for Nematus leucapsis and placed Nematus coriaceus as its junior synonym (see clarification in Taeger et al. 2010: 11). He considered P. leucapsis to be monophagous on Salix cinerea . It is obvious that Benson’s (1940, 1958) interpretation of Nematus leucapsis refers to a taxon different from that re-described under this name by Kopelke (2007b). Very confusingly, specimens that key to P. leucapsis or P. alienata as defined by Kopelke, run in the keys by Benson (1958) and Zhelochovtsev & Zinovjev (1993) to Pontania coriacea or respectively Nematus coriaceus , whereas species treated under the name leucapsis by earlier authors, including Benson (1958) are regarded by Kopelke as comprising a whole group of strictly monophagous taxa (i.e., each on a single willow species) under several names (see further under Phyllocolpa plicaphylicifolia ). After using the key and consulting descriptions by Kopelke (2007b) we had some doubt as to whether the Meall nan Tarmachan ‘ P. coriacea ’ specimens should be identified as P. leucapsis or P. alienata (Förster, 1854) . As illustrated by Kopelke, the possible differences in morphology of the ovipositor and penis valve are in any case small. Weak and possibly variable characters of the Meall nan Tarmachan specimens such as distribution of ctenidia on the basal annular sutures, the incurved lower edge of the sawsheath apex and the shape of the base of the penisvalve, seemed initially to support the identification as leucapsis rather than alienata . However, the long, dark cerci of the Scots specimens, reaching almost as far as the sawsheath apex, agree only with P. alienata as characterised by Kopelke. He described the cerci of P. leucapsis as [translated] “pale [and] extending at most half the length of the sheath” whereas those of P. alienata are described as “dark brown and long, extending more than half of the sheath length”. After examining two female specimens from Meall nan Tarmachan, Dr Kopelke commented that they are probably P. alienata rather than P. leucapsis and that his own material of P. alienata from northern Europe [Scandinavia] was similarly coloured, with a similar sawsheath and cerci (Kopelke, pers. comm.).