A tank test technique was developed to evaluate the resistance of one-year-old stems of 111 Malus rootstock cultivars and hybrids to pine vole damage. The tank fest proved to be an excellent method for: testing several clones at one time; providing the animals with more of a natural environment; exposing all animals to each stem in the test; and using small quantities of wood per experiment. Robusta 5 and PI 286613 when crossed with cultivars possessing other horticulturally desirable characteristics, produced several progeny containing varying degrees of vole resistance. Some other cultivars displaying high resistance to pine vole damage were: Fusca (M. fusca (Raf.) Schneider); M. sieboldii Rehd. cv. zumi·calocarpa; M. X sublobata (Cipp.) Rehd. PI 286613; NY 11928 (M. pumila niedzwetzkiana x M. atrosanguinea (Spaeth) Schneider) ; and Vilmorin (M.yunnanensis (Franch) Schneider). / Master of Science