The rind hardness of the lowest internode enclosed by the uppermost leafsheath in which first instarDiatraea saccharalis(F.) larvae were found was determined for 8 commercial sugarcane varieties. A highly significant negative correlation (r= –.97) was found between the internode first accessible to attack and mean percent internodes subsequently bored byD. saccharalislarvae: The possibility of using this technique to differentiate host resistance toD. saccharalisin sugarcane breeding programs is promising.