Factors Affecting Resistance of Alfalfa Clones to Adult Feeding and Oviposition of the Alfalfa Weevil in the Laboratory1

Factors affecting the resistance of 25 alfalfa clones to oviposition and feeding of adult alfalfa weevils, Hypera postica (Gyllenhal), were evaluated in the laboratory. Significant differences were found among clones for feeding and oviposition. The 2 responses were interrelated, and both were significantly related to stem diameter and to larval damage observed in the field. Although the clones differed in stem hardness, this fact did not influence fluence oviposition, nor did variations in stem age have any effect on oviposition.