Bumblebee

The bumblebee are any of the species of bees belonging to the taxonomic genus bombus. The bumblebee is well known for its stinger that is used in self defense and for its complex colonies. Their colonies are, however, much smaller than those of other species, containing only around 50-150 bees. These bees live in a symbiotic relationship with flowers, from which they gather pollen and nectar.  The bumblebees rely on the nector and pollen for food and the flowers depend on the bees for reproduction.

Anatomy
The bumblebee can be divided into three sections: the head, thorax, and abdomen. The head contains the eyes, mouthparts, and antenna. The bumblebee has compound eyes and three "primitive" eyes called ocelli. The compound eye is formed with many hexagonal units called ommatidia. The lens, which is the outside part of the eye lies over the crystalline cone. Underneath the lens are visual cells that are ultraviolet, blue, and green-sensitive. The primitive eyes are set in a triangular pattern that is on the top of the head.

The bumblebee tongue is used to suck up nectar. The long, reddish-colored tongue is kept inside a sheath and folded under the head and thorax when the bumblebee is at flight or at rest. Hair grows at the end of the tongue and is used for soaking up nectar. The bumblebee also has hairs with pores in them on its tongue and mouthparts. The molecules pass through the pores and attach to receptor sites on the sensory cells so that the bee can smell and taste. The antennae are used for touching. The two antennae help detect the direction of smell and help decide how close they can stay to the source. The bumblebee doesn't have ears but it can feel vibrations and sounds through wood and other materials.

The thorax includes wings, wing muscles, and legs. Many people think that the bumblebees only have two pairs of wings, but are unaware that there is a pair of small rear wings that are attached to the fore wings by a row of hooks. These hooks are called hamuli. The average wing beats per second is 130-240. Scientists say that the bumblebee should not be able to fly because of the such short wing beat per second but yet the bumblebee still flies. The "buzz" sound that comes from bees is from their wings flapping together. The legs on the bumblebee have combs and brushes. The female bumblebee uses these to gather pollen that attaches to her and she collects it in her pollen basket. Workers and queens have two baskets on each side of their hind legs. You can tell if a queen has a nest depending on weather her pollen baskets are full.

The abdomen contains the digestive and reproductive organs and sting. The bumblebee breathes through paired holes down the side of its body, called spiracles. These are attached to tubes called the trachea. The blood just moves around and is not carried into the veins and arteries. The body organs, heart, muscles, and other parts just sit in the pool of blood. The heart runs down the entire length of the bumblebee and pulses blood. Only the workers and queens can sting. They can sting more than once, unlike the honeybee. The stinger hides inside the last abdominal segment when it is not being used.

Reproduction
There are 4 cycle stages for the bumblebee colony. 1) Queen emerges from hibernation and starts a new colony by herself. 2) Workers are produced and start to forage; the colony develops and grows. 3) Unfertilized eggs are laid and worker larva develop into new queens. 4) Males and new queens mate, the colony disintegrates, the old queen, workers and males die, and new queens hibernate. Most bumblebees have a year long cycle. Pollen stimulates the ovaries to produce eggs.

The ovaries are activated in fertilized queens. When she lays a pearly white egg it passes along to the vagina. The container in the vagina is called a apermatheca which is where she stores sperm for her mating. Non-fertilized eggs become male bumblebees and fertilized eggs become females and queens. Although the bumblebee is very hairy it can still keep her eggs warm underneath her where there is a patch of no hair. Hormones are a big part of the growth and development of the bumblebee.

Ecology
A returning bumblebee will do a little dance over the honey combs to move the workers out of the nest. Bumblebees have a very unique way of communicating. It is known to involve pheromones, which is a chemical substance secreted by one animal that stimulates or inhibits the behavior of another animal. Nectar is what the bumblebee uses for energy to fly. Bumblebees can mark a flower so they won't go to flowers that have already been visited. All bumblebees have to learn how to get pollen and nectar from flowers, it doesn't just come naturally. They get rewarded for little things they do, just like dogs. They earn a treat for standing on the edge of the flower and trying to get to the middle.