Seedcorn maggot flies,Delia platura(Meigen) showed an innate oviposition preference for lima beans over acorn squash seeds and for snap beans over watermelon or cantaloupe seeds in laboratory tests. These preferences were not significantly altered by prior exposure of adult flies over a 3-week period to a single type of seed. Flies reared as larvae on single types of seeds also did not differ significantly in their oviposition preferences. Total numbers of eggs laid varied, depending on both prior exposure and larval host.