Four new species of Pteromalus Swederus (Hymenoptera: Chalcidoidea: Pteromalidae) and redescriptions of three other species

A key to the European species of the Pteromalus altus group is presented. The relationship between this group and species of the genus Euphorbia (Euphorbiaceae) is confirmed. One new species: P. villosae, associated with Euphorbia villosa Waldst. & Kit.is presented. Two new species of the albipennis group: Pteromalus almeriensis and P. costulata are presented. In addition one species of the P. vibulenus group: P. tethys is added. Information on P. sylveni Hedqvist, P. osmiae Hedqvist and P. discors Graham is given.