New data on the morphology, distribution and host plants of three species of the Terellia virens group (Diptera: Tephritidae)

New data on the morphology, distribution and host plants of three species from the Terellia virens group are provided. Terellia freidbergi Korneyev, 2013 and T. ivannikovi Korneyev et Evstigneev, 2013 are redescribed based on fresh specimens having the body shape and colour characteristic of living flies. Terellia zerovae Korneyev, 1985 is recorded for the first time from Russia; T. ivannikovi, previously known from the Samara Province of Russia, is recorded for the first time from Armenia and from the Saratov and Ul’yanovsk provinces of Russia. Centaurea takhtajanii Gabrieljan et Tonjan is recorded for the first time as a host plant of T. ivannikovi. In Armenia, the larvae of T. freidbergi develop in capitula of C. kotschyi persica (Boiss.) Greuter, C. (Chartolepis) sp., C. polypodiifolia Boiss, C. daralagoezica (Fomin) Greuter and C. spectabilis (Fisch. et C.A. Mey) Sch. Bip.; all these taxa are recorded for the first time as host plants of T. freidbergi. A key to identification of seven species of the T. virens group occurring in Armenia and Russia, is provided.