Vespula pensylvanica, yellowjackets, were attracted to artificial flower patches, made repeated foraging trips, and returned on successive days. We ob- served the foraging patterns of Vespula pensylvanica in blue-yellow color-dimor- phic and clove-peppermint odor-dimorphic artificial flower patches, with variable sucrose molarities and volumes, as previously used to study honey bees. Yel- lowjackets foraged randomly in color-dimorphic patches regardless of reward volume or odor. When one morph provided 1.5 M sucrose, the other 2.5 M sucrose, vespulid wasps foraged randomly. When one morph provided 1.5 M sucrose, and the other flower morph 0.75 M sucrose, yellowjackets visited ran- domly but only drank the richer solution. In odor-dimorphic monochromic patches yellowjackets foraged randomly.