Technical Abstract: Production of sweetpotatoes is severely limited by several insect pests, including Diabrotica spp., and new pest management approaches for this crop are needed. A host plant resistance research program typically depends on reliable bioassay procedures to streamline evaluation of germplasm. Thus, a bioassay technique was developed for adults of two cucumber beetle species (Diabrotica balteata and D. undecimpunctata). For this bioassay, a piece of sweetpotato peel (periderm & cortex with stele removed) was embedded periderm-side up in plaster in a Petri dish, and a single adult was placed on it. Plugs were changed as needed and adult longevity was measured. Adult longevity ranged from approximately 7-8 days for starved individuals to over 200 days for beetles fed a dry artificial diet. Longevity of adults fed sweetpotato peels ranged from 10 days for the most resistant genotypes to over 100 days for SC1149-19, the susceptible control genotype. This bioassay was consistent with field results, indicating that this technique could be useful for evaluating pest resistance in sweetpotato genotypes for Diabrotica and other insect species.