Host plant specificity in Pontania raises many questions and requires intensive experiments. The present study shows that two "food plant races", of what traditionally is considered a single species of Pontania, have proved to be new sibling species: P. nigricantis n.sp. and P. helveticae n.sp. These species are absolutely species-specific and make galls on Salix nigricans SM. and S. helvetica VILL. In size the galls look like those of P. dolichura (THOMSON) but they differ in colour. P. nigricantis and P. helveticae have of prolonged diapause and thus only one generation per year is realized. Sometimes the larvae of a small, slender moth (Epinotia (Steganoptycha) subocellana (DONOVAN), Tortricidae) develop in the galls, feeding on the gall tissues and frequently destroying the gall inhabitant. Four hymenopterous parasitoids were reared from the sawfly larvae: the pteromalid Pteromalus dolichurus (THOMSON), the ichneumonids Scambus vesicarius (RATZEBURG) and Aptesis nigrocinctus (GRAVENHORST), and the braconid Bracon fulvus SZEPLIGETI. Supplementary cocoon parasitism of the true Pontania dolichura was studied. The ichneumonid Theroscopus hemipterus (FABRICIUS) var. insignipennis SCHMIEDEKNECHT has proved to be a common cocoon parasite of this gall-making sawfly.