We report observations on the larval gregarious behaviour, host plant use and parasitoids of six species of melitaeine butterfly in the Russian Republic of Buryatia. We observed post-diapause larvae in two habitats, steppe and taiga forest region. Five species were found in the steppe region: Euphydryas aurinia davidi, Melitaea cinxia, M. latonigena, M. didymoides and M. phoebe. Three species (M. cinxia, M. latonigena and M. didymoides) fed on the same host plant, Veronica incana (Plantaginaceae). Euphydryas aurinia larvae were found on Scabiosa comosa (Dipsacaceae) and M. phoebe larvae on Stemmacantha uniflora (Asteraceae). Three species were found in the taiga region (M. cinxia, M. latonigena and M. centralasiae), of which the first two fed on Veronica incana. Five species of hymenopteran parasitoids and three species of dipteran parasitoids were reared from the butterfly larvae of five species. Erycia fasciata (Tachinidae ); Cotesia acuminatus (Braconidae ); Lepidopteran hosts; Melitaea latonigena; New host record; Russia; Buryatia; New lepidopteran host record Nemorilla maculosa (Tachinidae); Lepidopteran hosts; Melitaea didymoides; New host record; Russia; Buryatia; New lepidopteran host record Melitaea didymoides (Nymphalidae); Dipteran parasites; Nemorilla maculosa; New host record; Russia; Buryatia; New dipteran parasite record Melitaea latonigena (Nymphalidae); Dipteran parasites; Erycia fasciata; Hymenopteran parasites; Cotesia acuminatus; New host record; Russia; Buryatia; New dipteran & hymenopteran parasite records Melitaeini (Nymphalidae); Food plants; Dipteran parasites; Tachinidae; Hymenopteran parasites; Habitat preference; Russia; Buryatia; Larval biology none