Review of the sequester group of Pteromalus Swederus, 1795 (Hymenoptera, Pteromalidae) with description of three new species

Palaearctic species of the <i>sequester</i> group of <i>Pteromalus</i> Swederus, 1795 are reviewed. Three new species, <i>P. boleensis</i> Yan, Li & Tselikh, <b>sp. nov.</b> (Kazakhstan, China), <i>P. longipedicellus</i> Yan, Li & Tselikh, <b>sp. nov.</b> (China) and <i>P. oscolensis</i> Tselikh, <b>sp. nov.</b> (Russia, China) are described and illustrated. Types of <i>P. cionobia</i> (Erdös, 1953) and <i>P. sequester</i> Walker, 1835 are redescribed. An identification key to females of the <i>sequester</i> group of <i>Pteromalus</i> is given.