Previous studies have indicated that certain alfalfa varieties and clones are more resistant than others to alfalfa seed chalcid damage. This resistance varies in all cases and data on infestations indicate that agronomic characteristics may be responsible for some of the apparent resistance. Since this is a major pest in alfalfa seed producing areas, and cultural and chemical controls have been essentially ineffective, it was decided to determine if resistance was associated with certain pod characteristics in order to find a partial solution to the problem.