Honey Bee Biology
Honey bees (Apis mellifera L.) are one of mankind’s most well-known, popular and economically beneficial insects. For thousands of years, humans have plundered natural honey bee colonies to get honey, bee larvae and beeswax. In more recent centuries, bee plundering has given way to bee management. Today, honey bees are kept in artificial hives throughout the United States, and a large and sophisticated beekeeping industry provides valuable honey, beeswax and pollination services. A large section of the industry, well represented in Georgia, is devoted to producing queens and bees for sale to other beekeepers. Although many people make a living from bees, most beekeepers are hobbyists who have only a few hives and who simply enjoy working with these fascinating insects.
Honey Bee Castes
Honey bees, like ants, termites and some wasps, are social insects. Unlike ants and wasps, bees are vegetarians; their protein comes from pollen and their carbohydrate comes from honey which they make from nectar. Social insects live together in groups, cooperate in foraging tasks and the care of young, and have different types, or "castes," of individuals. In honey bees there are two genders, the females of which are further divided into two castes – sterile workers and fertile queens:
- Workers - Reproductively underdeveloped females that do all the work of the colony. A colony may have 2,000 to 60,000 workers (Fig. 1).
- Queen - A fully fertile female specialized for producing eggs. When a queen dies or is lost, workers select a few young worker larvae and feed them a special food called "royal jelly." These special larvae develop into queens. Therefore, the only difference between workers and queens is the quality and quantity of the larval diet. There is usually only one queen per colony. The queen also affects the colony by producing chemicals called "pheromones" that regulate the behavior of other bees (Fig. 2).
- Drones - Male bees. A colony may have 0 to 500 drones during spring and summer. Drones fly from the hive and mate in the air with queens from other colonies. Drones are kicked out of the hive during the winter months (Fig. 3).
The queen lays all her eggs in hexagonal beeswax cells built by workers. Developing young honey bees (called "brood") go through four stages: the egg, the larva (plural "larvae"), the inactive pupa (plural "pupae") and the young adult (Figures 4-6). The types of bees have different development times (Table 1). These intervals, however, are literature averages and do not always apply locally. For example, it is common for worker bees in Georgia to emerge in 19 days and queens in 15.
Table 1. Development time of honey bee castes.
Newly-emerged workers begin working almost immediately. As they age, workers do the following tasks in this sequence: clean cells, circulate air with their wings, feed larvae, practice flying, receive pollen and nectar from foragers, guard hive entrance and forage.
Unlike colonies of social wasps and bumble bees, honey bee colonies live year after year. Therefore, most activity in a bee colony is aimed at surviving the next winter.
During winter, bees cluster in a tight ball. In January, the queen starts laying eggs in the center of the nest. Because stored honey and pollen are used to feed these larvae, colony stores may fall dangerously low in late winter when brood production has started but plants are not yet producing nectar or pollen. When spring "nectar flows" begin, bee populations grow rapidly. By April and May, many colonies are crowded with bees, and these congested colonies may split and form new colonies by a process called "swarming." A crowded colony rears several daughter queens, then the original mother queen flies away from the colony, accompanied by up to 60 percent of the workers (Fig. 7). These bees cluster on some object such as a tree branch while scout bees search for a more permanent nest site - usually a hollow tree or wall void. Within 24 hours the swarm relocates to the new nest. One of the daughter queens that was left behind inherits the original colony.
After the swarming season, bees concentrate on storing honey and pollen for winter. By late summer, a colony has a core of brood below insulating layers of honey, pollen and a honey-pollen mix. In autumn, bees concentrate in the lower half of their nest, and during winter they move upward slowly to eat the honey and pollen.