Yellow jacket

Yellow Jackets are any of the species of wasps belonging to the taxonomic genera Vespula and Dolichovespula. They are very aggressive and social insects that live in colonies and eat sweets like fruit and nectar. Their name is derived from their characteristic yellow and black stripes alternating around its body. They are about half an inch long with almost no hair unlike a bumblebee. These insects live mostly in wall cavities of urban areas and underground also unlike other bees which build nests up high in trees or elevated places. Yellow jackets also have huge compound eyes which wrap around their head and translucent thin wings.

Anatomy
A yellow jacket is only about half an inch long and has black and yellow stripes alternating across its body, although the bald-faced hornet, Dolichovespula maculata, is black and white. The yellow jackets has six jointed legs,two compound eyes, few or no hairs,and very slim waists.Since males have to mate, only the female yellow jackets have stingers. They have mandibles,or jaws, and four wings which are translucent, and two black antennae. Yellow jackets have a hard exoskeleton and have all three parts of a insect body; the head, thorax, and abdomen.

Circulatory system: The yellow jacket has an open circulatory system, in which the blood flows into the body cavity directly bathing the internal organs. The blood is not separated, and this is common in arthropods. Since the heart pumps the blood into the body cavities the blood flow is very sluggish.

Nervous system: Its nervous system is made up of a brain, which has three pairs of ganglia used for different functions.The first pair, the protocerebrum, controls vision. The deutocerebrum innervates the antennae; and the last pair, the tritocerebrum, controls the labrum, and also connects the rest of the nervous system to the brain. It also has a central nervous cord which connects the brain and subesopagheal ganglion to additional ganglion in the thorax and abdomen. Below the brain there is a set of fused ganglia that forms the subesopagheal ganglion, which controls the salivary glands, mouthparts, and neck muscles.

Reproduction
Yellow jacket reproduction is a annual cycle.Only queens who have mated survive the winter by hiding in protective places such as dense bushes and abandoned rodent nests.When spring arrives,the queen emerges and starts a colony and builds a paper nest with 30-50 brood cells in them,then lays 10 to 20 eggs inside the nest.The queen feeds the larvae for about 20 days; then the larvae pupates and emerges as infertile workers. The queen will continue to lay eggs until her death in autumn while the workers feed and protect the colony. There are three classes that they are separated into; queens, workers, and drones. Numbers usually max at 4,000 to 5,000 in the colony. These colonies usually only last one season and die off in the winter;which is restarted all again by another queen.

Ecology
The Yellow jacket being a very aggressive insect does not get along with other organisms in their habitat, although they do use the environment for sweets like nectar and fruits. Their habitat is also used for hives, which are usually underground or in wall cavities unlike the other wasps which have hives up in trees or high places. In fact, these aggressive insects use other insects to pre-chew and then feed their larvae; so most other organisms try to stay away. These predatory insects live off themselves and the environment and do not rely on any other organisms.Since the habitat of this insect is usually urban, it brings them into contact with people when they are foraging for food and commonly ends up with a painful sting; although it is usually not very serious.

Characteristics
Yellow jackets are easily distinguishable by their yellow and black coloring. They measure in length from about 12mm to 16mm(or .47in to .63in). They live all throughout North America and are a common sight. The Yellow jacket is a extremely aggressive insect, especially the females who will sting repeatedly, and get upset if you were to swing at them. They live through the summer and spring, until the males die off in the fall and leave the mated females to continue generations into following year.