SummaryFive groups of honeybee colonies were tested for their tendency to collect alfalfa pollen. One group was the sixth generation of a line with a strong tendency to collect this pollen (high line); another was the sixth generation of a line with a low tendency to collect it (low line). In these two groups an average of 86% and 8%, respectively, of the pollen collectors collected alfalfa pollen; this represented little improvement over the fifth generation (Nye&Mackensen, 1968). A third group was a commercial strain (which ranked low, 31%), but the fourth (an outcross of high-line queens to drones of the commercial strain) and a fifth (an outcross of high-line drones to queens of another stock) ranked intermediate, at 52% and 59%, respectively, and were significantly higher than the commercial strain. The number of alfalfa pollen collectors was highest (29) in the high line; it was the same (18) in both outcrosses, this being slightly but not significantly higher than in the commercial strain (16). The number of nectar collectors and the yield of honey were roughly proportional to the amount of inbreeding in each group.