Honey bees (Apis mellifera, Apidae) are fascinating to watch. The phrase “as busy as a bee” certainly has a lot of truth to it. These bees are constantly moving, buzzing from flower to flower, stopping only for a few seconds to drink nectar and collect pollen.
The bees drink nectar both for their own nourishment and for the production of honey. They gorge themselves on it and then regurgitate most of it back in the hive, saving only enough for their own needs. The nectar that is collected at the colony is transformed into honey as the water evaporates from it. The sugar-rich honey is used for food in the winter.
Pollen is also collected as a food source for larvae. It’s rich in protein, which is vital to larval development. Worker bees collect it and place it in pollen baskets (corbiculae) on the tibiae of their hind legs. Stiff hairs (setae) on their legs help hold the pollen in place until the workers returns to the colony. You can see the mass of pollen on the corbicula of this worker’s rear left leg.
Honey bees serve as important pollinators of flowering plants (angiosperms) like this goldenrod (Solidago sp., Asteraceae) and, more importantly to us, of commercial crops. As they collect pollen and move from flower to flower, a little falls off along the way. Some of the pollen (male gamete) can fall on the stamens (external female reproductive structure) of another flower. The transport of pollen to the stamen is pollination, but fertilization is required for angiosperm reproduction. Once a pollen grain reaches a stamen, if it’s sexually compatible it will grow through the pistil to the ovule (female gamete). Only then can the ovule be fertilized and subsequently develop into a seed.
All worker bees like this one are sterile females. Male bees (drones) exist only to attempt to mate with the queen (the only fertile female). This sounds like a great deal for the males, but apparently they get evicted from the hive as winter approaches. The males only serve to contribute sperm to the queen, and by late in the year the queen has already mated with a select few drones and stored their sperm internally (in a spermatheca). Since the males no longer serve a purpose, they would be a drain on the colony during the lean winter months. Outside of the hive the males end up dying, but have probably lived longer on average than the female workers.
Although most people probably think of honey bees when someone says “bee,” they comprise only 7 of the over 20,000 known bee species. There are no honey bees native to North America; the species above (Apis mellifera) was brought here by Europeans in the seventeenth century.