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Man and Domestic Animals
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Insects and other Arthropods can cause injury and even death
by their bites or stings. More people die each year in the
United States from bee and wasp stings than from snake bites.
Many insects can transmit bacteria and other pathogens that
cause diseases. During every major war between countries,
more people have been injured or killed by diseases transmitted
by insects than have been injured or killed by bullets and bombs.
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Insects that bite man and domestic animals are mostly those
with piercing-sucking mouthparts, as found in Hemiptera and
some Diptera. Much of the discomfort from a bite is a result
of enzymes that the insect pumps into the victim. Insects
with mandibles, such as grasshoppers and beetles, have the
ability to bite if they are held carelessly. However,
insects with mandibles do not cause as much pain because they
do not release enzymes.
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Harmful spiders include the black widow and the brown recluse.
The black widow has a venom that affects a person's nerves, and
death can result if medical treatment is not obtained. The
venom of the brown recluse, or fiddle-back spider, destroys
the skin and tissue around the area of the bite, which can
become seriously infected if not treated.
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Ticks and chiggers are different kinds of mites (Class
Arachnida) that feed on blood of animals. Ticks can also
transmit viruses and other pathogens that cause diseases,
including Lyme disease and Rocky Mountain spotted fever. Other
kinds of mites can cause mange on humans, dogs, cats, and other
animals.
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Order Hemiptera includes bed bugs, kissing bugs, and assassin
bugs, all of which have beaks for piercing their hosts. Bed
bugs are not a common pest in people's houses, and they cannot
transmit any diseases. The most painful bites among all insects
are those of assassin bugs. Kissing bugs are involved in
causing Chagas disease in Central and South America.
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Order Phthiraptera includes sucking lice and chewing lice.
Most chewing lice feed on skin and feathers of birds,
especially chickens. The sucking lice include species that
feed on blood of humans, horses, cattle, and other domestic
animals. Head lice are found on a person's head where they
lay their eggs, termed nits, on the hair. Body lice lay their
eggs on clothing and are less common than head lice. Body lice
transmit pathogens causing typhus and other diseases.
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The caterpillars of some moths can "sting." The venom does
not come from a stinger, as in wasps, but rather from spines
and hairs on the caterpillar's body. Many stinging caterpillars
have bodies with a mixture of bright colors.
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The Diptera are the most important order of insects that
affect people. Biting flies include many species of mosquitoes,
black flies, biting gnats, horse flies, and others. Many of
these biting flies are transmitters of diseases, such as the
tse-tse fly that transmits African sleeping sickness. Flies
with sponging mouthparts, such as the house fly, also transmit
bacteria and other pathogens that cause typhoid fever and other
diseases. Screwworms and maggots of bot flies are fly larvae
that invade living tissue of animals.
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Mosquitoes transmit pathogens that cause malaria, yellow fever,
encephalitis, and other diseases. Malaria is caused by a
protozoan parasite that lives part of its life cycle in the
Anopheles mosquitoes and part of its cycle in humans. During
one recent year, malaria resulted in more than two million
deaths throughout the world, mainly in tropical areas.
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Plague, also known as bubonic plague or black death, is caused
by bacteria that infect rats and other rodents. The main
transmitter of this disease to humans is the Oriental rat flea
(Order Siphonaptera). A plague epidemic in Europe during the
14th century claimed 25,000,000 lives, one fourth of the
population of the continent. The last major epidemic
occurred in India in 1906 when more than 675,000 people died.
Although there have not been major epidemics in the United
States, there are isolated cases of plague every year, mostly
in the western states.
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Many bees, wasps, and ants (Order Hymenoptera) can cause pain
and even death by their stinging. Most cases of stinging
happen when people disturb the nests or do something to
threaten the wasp or bee. Deaths usually are a result of
allergic reactions to the venom. In a 1988 survey, physicians
treated 20,755 patients for reactions to fire ant stings in
southern United States. Other major stingers include hornets,
yellow jackets, and paper wasps.
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The Africanized honey bee, or "killer" bee is a strain of our
domesticated honey bee. The two strains are almost identical
in appearance. However, the Africanized strain is much more
aggressive and will attack in larger numbers. The Africanized
strain was introduced into South America to improve honey
production. In recent years, it has spread through Central
America into Texas and other coastal states.
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Photographs of insects and arachnids that affect man and animal,
along with additional information, can be found at
Insects,
Disease, and History.
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Food, Clothing, and Housing
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Insects attack grains, vegetables, and fruit in the fields as
well as food that is stored in our houses. Some will eat our
houses, if made from wood, and others will eat our furniture,
carpets, and clothing. Many insects transmit viruses, fungi,
and other pathogens that cause diseases on plants.
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More insecticides are used on cotton than any other field crop
to prevent damage from the boll weevil, bollworm, and
budworm. The bollworm is the caterpillar of the moth,
Helicoverpa zea, and it also is known as the corn earworm and
tomato fruitworm. The budworm,Heliothis virescens, is also a
pest of tobacco. Other pests include the tarnished plant bug
(Order Hemiptera) and thrips (Order Thysanoptera).
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Corn is attacked by corn borers and cutworms (caterpillars of
moths), wireworms (larvae of click beetles), and rootworms
(larvae of leaf beetles). Other pests, which also attack
wheat, include aphids, leafhoppers, grasshoppers. The
Hessian fly is a pest of wheat that was brought to this country
from Europe during the Revolutionary War.
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Vegetable pests include caterpillars such as cabbage loopers,
armyworms, hornworms, and webworms. Other pests include the
Mexican bean beetle, Colorado potato beetle, cucumber beetles,
potato leafhopper, and blister beetles. Many vegetables are
grown in greenhouses and are attacked by various Homoptera,
including whiteflies, scale insects, mealybugs.
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Major pests of apple include the codling moth, apple maggot,
and leaf-roller moths. Peaches and plums are attacked by plum
curculio, peach tree borer, and Oriental fruit moth. Citrus
fruits are injured mostly by Homoptera, including scale insects,
mealybugs, and whiteflies. Leafhoppers, mites, aphids, and
thrips also are pests of many fruits.
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Forest and shade trees have a large number of Homoptera,
Coleoptera, Lepidoptera, and other insect pests. Many kinds
of trees and shrubs are attacked by the gypsy moth and Japanese
beetle in eastern United States. Bark beetles are the greatest
enemies of pine and other conifer trees. Larvae of sawflies,
which are plant feeding Hymenoptera, are pests of spruce and
pines.
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Houses and other wood products can be destroyed by termites,
powder post beetles, and carpenter ants. The subterranean
termite and Formosan termite are the most serious pests of
houses in the southern United States and tropical regions.
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Any harvested plant or animal product can be attacked by
insects. Flour beetles, grain weevils, meal moths and other
stored product pests will feed on stored grain, cereals, pet
food, powdered chocolate, and almost everything else in the
kitchen pantry that is not protected. Larvae of clothes
moths eat clothes made from animal products, such as fur, silk
and wool. Larvae of carpet beetles eat both animal and plant
products, including leather, fur, cotton, stored grain, and
even museum specimens. Book lice and silverfish are pests of
libraries. These insects eat the starchy glue in the bindings
of books.
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Other insects that have invaded houses include cockroaches which
eat almost anything. Cockroaches are not
known to be a specific transmitter of disease, but they
contaminate food and have an unpleasant odor. They are very
annoying, and many pest control companies are kept busy in
attempts to control them. The most common cockroaches in houses,
grocery stores, and restaurants include the German cockroach,
American cockroach, Oriental cockroach, and brown banded
cockroach.
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Many harmless insects enter houses accidentally. Insects
attracted to porch lights rarely include biting and stinging
species or household pests. Bug-zappers and poppers use
electricity to kill insects that are attracted to a light.
Studies have shown that these kill mostly harmless insects. Of
13,789 insects killed in six zappers during one summer, only
31 were biting flies. As winter approaches, some insects will
enter houses to hibernate. The queens of wasps often hibernate
in attics and wall spaces, but these do not sting.
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Photographs of pest species with additional information can be
found at
Kansas Department of Agriculture. . .Photo Gallery and
University of Nebraska-Lincoln: Images/Insects & Their Relatives.
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