Feeding bees with engineered yeast combats colony decline

Nutritionally complete food for honeybees (Apis mellifera) has been generated by engineering yeast to produce rare but essential sterol molecules found in pollen. Honeybee colonies fed with the yeast-supplemented diet produced offspring for longer periods than did those fed sterol-deficient diets. This approach makes it possible to rear honeybees without pollen. Yeast genetically modified to produce sterol molecules found in pollen provides a nutritionally complete diet for honeybees.