Pontania herbaceae ( CAMERON , 1876)

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 : 46

Pontania herbaceae ( CAMERON, 1876)

Perthshire, Garbh Mheall, 8 ♀♀ 1 ♂, reared from galls on Salix herbacea , collected August 2000, leg. Bland.

The type locality of Nematus herbaceae given by Cameron (1876) for the reared adult syntypes on which he based his description is “ Ben Lawers and on “Garyvel”, Rannoch”. The name of the latter locality has puzzled later entomologists. Vikberg (2003) designated a lectotype and thereby restricted the type locality to “Rannoch”. The mountain referred to by Cameron as “Garyvel” (more usually spelled by his contemporaries Grayvel, but also named for example Garvell or Gharbhavel) is Garbh Mheall (also named Mheall Garbh on some maps) (+ 56.623783 -4.446745, NN 500507, summit 986 m), situated 6 km south of Bridge of Gaur, at the West end of Loch Rannoch. This has been a popular destination for entomologists since the Victorian era (see for example Rye 1866; Fowler 1887; [Lloyd] 1895), usually approached from the North: such an ascent is described in fair detail by Metcalfe (1918).

Whilst the combination of gall type and host Salix species readily identifies most Pontania species in Britain, Pontania herbaceae and P. aquilonis Benson, 1941 are exceptional in making the same type of gall on the same host. Whilst the adults can be difficult to distinguish, the larvae of P. herbaceae (3 dorsal annulets on abdominal segments, body laterally with pattern of groups of black spicules) can easily be distinguished from those of P. aquilonis (4 annulets, groups of black spicules absent) ( Vikberg 2003). In recent years Liston has examined larvae extracted from galls on S. herbacea from several Highland localities (Perthshire, Angus, Cairngorms) and around White Coomb in the Southern Uplands, as well as adults reared by Bland from various parts of the Highlands. They all belong to P. herbaceae . The only record of the apparently much rarer P. aquilonis Benson, 1941 in the British Isles is based on the type series of P. algida Benson, 1941 collected on Meall na Samhne, Perthshire ( Benson 1958, Vikberg 2003). The types of the latter are adults and nothing is recorded about the appearance of the larvae. Dr Vikberg told Liston in conversation that he still had some doubts, after morphological comparison of the types, that P. algida was really distinct from P. herbaceae . We should continue to try to establish whether P. aquilonis is now present at any British sites. Pontania herbaceae is recorded widely from many of the British populations of Salix herbacea ( Scotland; probably throughout, wherever S. herbacea still occurs: Scotland; Fair Isle (Nick Riddiford, pers. comm.) [but not otherwise known in Shetlands], through Orkney, Western Isles (sometimes near sea-level) and most mountain summits further south and east over 700 m, including the southern uplands. England; highest summits in northern Pennines and Lake District. Wales; Snowdonia. Ireland; only known from summit of Slieve Donard, County Down [but has anybody really looked on the western mountains, e.g. in Donegal?]. The worldwide distribution of the species is discussed by Vikberg (2003).