There are times when bees need to have their food supplies supplemented . Sugar syrup is fed to bees when their own stores are insufficient to supply their needs. It can be made in two different ratios depending on the time of the year. Light syrup or spring syrup is 1 part sugar to 1 part water by either weight or volume. Heavy syrup or autumn syrup is made from 2 parts sugar to one part water.
The light syrup is similar to nectar. The availability of nectar stimulates the production of brood in the spring, and light syrup tends to do the same thing. With a ready supply of nectar or light syrup, the workers will draw comb and the queen will lay eggs.
Autumn syrup resembles honey in consistency and sugar content and bees tend to store it for winter. It is used in the autumn and winter if the beekeeper feels there is not enough honey stored in the hive to make it through the winter.
Plain white sugar is best for bees
It is important to use plain white granulated sugar not brown sugar as this has impurities that can cause dysentery in bees. Bee dysentery is not a disease caused by a pathogen but a condition caused by poor quality food. It appears as spots of feces around the hive entrance, or inside the hive, and can be confused with Nosema, which is caused by a pathogen.
For more information on feeding bees you can download a page from the BBKA at http://www.nationalbeeunit.com/downloadDocument.cfm?id=701