This research was conducted to determine host plant specificity and oviposition behavior ofBangasternus orientalisCapiomont andBangasternus fausti(Reitter) in a freechoice field experiment. Labeled adultBangasternusspp. were exposed equally to eight selected plant species and cultivars in a field experiment in Greece. Weevil/plant associations were quantified and weevils were reared and identified from randomized flower head samples from all blocks. AdultB. orientalisshowed overwhelming preference forCentaurea solstitialisL., although some attraction and oviposition occurred onCentaurea diffusaLam. andCentaurea calcitrapaL. AdultB. faustishowed strong preference forC. diffusa, but some attraction and oviposition occurred onC. calcitrapaandC. solstitialis. The evidence suggests that theseBangasternusspp. have a very restricted host-plant range, feeding only on a small number of plants in the genusCentaurea, and are potential candidates for biological control programs againstCentaureain California.