Blister beetles responded differently to three alfalfa cultivars and an experimental line in terms of feeding activity and longevity. Blister beetles consumed greater amounts of younger alfalfa than of mature alfalfa. Nutrient concentration tended to decrease as alfalfa growth stage progressed. Field investigations of naturally occurring densities of threestriped and margined,E. funebrisWerner, blister beetles revealed that ‘Kansas Common’ and ‘Arrow’ alfalfas were more attractive than were ‘Riley’ and ‘KS 210’, a glandular-haired experimental line. Several plant parameters, such as alfalfa stem height, stem density, and developmental stage may partially influence the occurrence of threestriped blister beetles,Epicauta occidentalisWerner, on these alfalfa cultivars or experimental lines.