Wasps and Hornets often are nuisances and can be dangerous to people because the female can inflict painful stings, most likely in defense of their nests. Common wasps found around the home include cicada killers, hornets, paper wasps, mud daubers, and yellow jackets. Paper wasps and hornets build paper-like nests under eaves of houses, in shrubs, and other protected places. Hornet nests are easily recognized as the large, covered, grayish-brown paper structures usually seen hanging from trees or bushes.
Cicada Killer Wasp
Cicada killer wasp. Cicada killers digs holes in lawns or the earth in which it places a cicada which it has captured and paralyzed. It lays an egg on the cicada which hatches and feeds on the cicada producing a new wasp. Cicada Killers, one of the least aggressive wasps, commonly attract attention because of their sheer size ranging from 1 ¼ to over 1 ½ inches long with black and yellow coloring. Cicada killer wasps will not sting or cause harm if left alone (only the male will buzz people). It is best left alone since it rarely stings. Although they are confused with other stinging insects, cicada killer venom is very mild and doesn't cause much more then a bump and red mark. Beware, individuals that are allergic to stings should still avoid these insects. Cicada killers have weak stings that are meant to paralyze their prey and damage the vertebrates, not cause pain.
Hornet. The common European hornet was accidentally introduced to North America around the middle of the 19th century. However, it has never been found in western North America. Hornets are the largest eusocial wasps, some species can reach up to 5.5 cm (2.2 in) in length. They have stings used to kill prey and defend hives. Hornet stings are more painful to humans than typical wasp stings because the venom contains a large amount (5%) of acetylcholine. Acetylcholine (often abbreviated ACh) is an organic, polyatomic ion that acts as a neurotransmitter in both the peripheral nervous system (PNS) and central nervous system (CNS) in many organisms including humans. People who are allergic to wasp venom are also allergic to hornet stings. Reactions are commonly treated with epinephrine (adrenaline) injection using a device such as an EpiPen ®, with follow-up treatment in a hospital. In severe cases, allergic individuals may go into anaphylactic shock and die unless treated promptly.
Mud Dauber Wasp
Mud Dauber wasp. So named because they construct their nests of mud in attics, under eaves, and on other parts of buildings. They are called "dirt dauber," "dirt digger," "dirt dobber," "dirt diver", and "mud wasp". They are usually black with yellow markings and have an elongated narrow "waist". They can be eliminated by tearing down their nests. They are not dangerous, they do not defend their nests and rarely sting. The metallic-blue mud dauber forgoes building a nest altogether and simply uses the abandoned nests of the other two species and preys primarily on black widow spiders. They are also the main predator of the black and brown widow spiders.
Paper wasp. Paper wasps are usually .7 to 1 inch (1.8 to 2.5cm) long. They gather fibers from wood and plant stems and construct nests that are gray or brown and are water repellant. They sometimes are referred to as umbrella wasps because of the design of the nest. The nests have open combs with cells. Paper wasps secrete a chemical which repels ants, protecting the nest. Nests are found in sheltered areas such as tree branches, open pipes or eaves of a building. They are important to the bio system and they feed on nectar and insects such as caterpillars and flies. Gardeners sometimes consider them beneficial. Paper wasps will only attack if their nest or themselves is threatened. Paper wasp stings can be painful and can produce a fatal reaction to people who are allergic. Nests in human inhabited areas can present a hazard.
Yellow Jacket Wasp
Yellow Jacket wasp. Common name in North America for these predatory wasps is yellow jacket. They are known as "wasps" in other English-speaking countries. Most of them are black and yellow with alternating bands on the abdomen, some are black and white (such as the bald-faced hornet), while others may have an abdomen background color that is red instead of black. Yellow jackets can be identified by their distinctive markings, small size (similar to a honey bee), they occur only in colonies with a characteristic, rapid, side to side flight pattern prior to landing. Females are capable of stinging. They have a lance like stinger with small barbs and will sting repeatedly, producing painful stings. The venom is dangerous to humans if they are allergic. Yellow Jackets build nests in trees, shrubs, or in protected areas such as attics, hollow walls or floors, sheds, under porches, under siding or eaves of houses. Despite having drawn the loathing of humans, yellow jackets are in fact important predators of pest insects.