
Apis mellifera is a species of honeybee commonly called the Western honeybee or European honeybee. Its genus name Apis is Latin for "bee", and mellifera means "honey-bearing". There are currently 29 extant subspecies. In the temperate zone honey bees survive winter as a colony, and the queen begins egg-laying in mid- to late winter in preparation for spring (probably triggered by day length). The only fertile female, she lays the eggs from which all the other bees are produced. Except for a brief periods (when she may fly to mate with drones or leave in later life with a swarm to establish a new colony), the queen rarely leaves the hive after the larvae have become bees. She deposits each egg in a cell prepared by worker bees. The egg hatches into a small larva fed by "nurse" bees (worker bees who maintain the interior of the colony). After about a week, the larva is sealed in its cell by the nurse bees and begins its pupal stage. After another week, it emerges as an adult bee. For the first ten days of their lives, female worker bees clean the hive and feed the larvae. After this, they begin building comb cells. On days 16 through 20, workers receive nectar and pollen from older workers and store it. After the 20th day, a worker leaves the hive and spends the remainder of its life as a forager. The average population of a healthy hive in midsummer may be as high as 40,000 to 80,000 bees. The larvae and pupae in a frame of honeycomb are known as "frames of brood", and are sold (with adhering bees) to start new beehives. Workers and queens are fed royal jelly during the first three days of their larval stage. Workers are then switched to a diet of pollen and nectar (or diluted honey), while queens will continue to receive royal jelly (which helps large, sexually developed larvae reach the pupal stage more quickly). Queen breeders consider good nutrition during the larval stage critically important for queen quality, with good genetics and sufficient mating contributing factors. During the larval and pupal stages, parasites may damage (or destroy) the pupa or larva. Queens are not raised in the typical horizontal brood cells of the honeycomb. A queen cell is larger and oriented vertically. If workers sense that an old queen is weakening, they produce emergency cells (known as supersedure cells) made from cells with eggs or young larvae and which protrude from the comb. When the queen finishes her larval feeding and pupates, she moves into a head-downward position and later chews her way out of the cell. At pupation, workers cap (seal) the cell. Shortly before emerging from their cells, young queens may often be heard "piping". The queen makes this sound to evaluate her space, and piping seems to calm worker bees. Although worker bees are usually infertile females, when some subspecies are stressed they may lay fertile eggs. Since workers are not fully sexually developed, they do not mate with drones. Fertile eggs would be haploid (having only the genetic contribution of their mother), and these haploid eggs would always develop into drones. Worker bees secrete the wax used to build the hive, clean, maintain and guard it, raise the young and forage for nectar and pollen. Worker honey bees have a modified ovipositor, a stinger, with which they defend the hive; unlike bees of any other genus and the queens of their own species, this stinger is barbed. Contrary to popular belief, a bee does not always die soon after stinging; this misconception is based on the fact that a bee will usually die after stinging a human or other mammal. The stinger and its venom sac, with musculature and a ganglion allowing them to continue delivering venom after they are detached, are designed to pull free of the body when they lodge. This apparatus (including barbs on the stinger) is thought to have evolved in response to predation by vertebrates, since the barbs do not function (and the stinger apparatus does not detach) unless the stinger is embedded in elastic material. The barbs do not always "catch", so a bee may occasionally pull its stinger free and fly off unharmed (or sting again).