Association of the clover root curculio,Sitona hispidulus(F.), with the alfalfa,Medicago sativaL., rhizosphere remains sketchy. The number of instars ofS. hispidulusthat develop on alfalfa and their feeding behavior was investigated under laboratory conditions. Larvae ofS. hispiduluswere exposed to alfalfa roots grown hydroponically on slant-board cultures. Based on the molting process as evidenced by shed exuvia,S. hispidulusdeveloped through five instars. Feeding of specific instars on alfalfa root components grown in the slant-board culture indicated that first and second instars fed primarily on the root nodules. As larvae grew, feeding shifted to the fibrous and lateral roots. The fifth instars preferred to feed on the lateral roots and the taproot. All instars fed on nodules but the propensity to feed in nodules was associated with the first and second instars ofS. hispidulus.