Technical Abstract: Over two-hundred and twenty crude extracts from repositories generated from plants native to Greece and Kazakhstan were evaluated for termiticidal activity against the Formosan subterranean termite species, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae). Emerging from this screening effort were bioactive extracts from two Greek species (Echinops ritro and Echinops spinosissimus subsp. spinosissimus) and extracts from two Kazakhstan species (Echinops albicaulis and Echinops transiliensis). Fractionation and isolation of constituents from the most active extracts from each of the four species has been completed resulting in the isolation of eight thiophenes possessing varying degrees of termiticidal activity. a-terthienyl (1) and 5'-(3-buten-1-ynyl)-2,2'-bithiophen (4) demonstrated 100 ± 0 percent mortality against C. formosanus within 9 days at 1 and 2 percent (wt/wt) concentrations, respectively. Additionally, all but two of the compounds tested were significantly different from the solvent controls in the filter paper consumption bioassay.