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Order:Hemiptera
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Common Name--True Bugs
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Names
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The order Hemiptera is pronounced "he-MIP-ter-a." This scientific name stems
from the Greek words "hemi," which means half, and "ptera," which means wings.
These names refer to the fact that the front wings of these insects are
usually thickened in the basal half (the part attached to the body) and
membranous at the ends. Another name that has been used for the true bugs is
Heteroptera. Heteroptera and Homoptera are sometimes included together as
suborders of Hemiptera.
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Although "bug" has been used as
a common name for any insect, this name was first used for species of
Hemiptera, and these insects are considered the "true bugs."
There are many common names for different groups of Hemiptera, including water
striders, water boatmen, backswimmers, toad bugs, minute pirate bugs, leaf
bugs, gnat bugs, ambush bugs, assassin bugs, damsel bugs, bat bugs, leaf-footed
bugs, stink bugs, and many more. Some of these groups are shown in the
Hemiptera Gallery.
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Diversity
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About 50,000 Hemiptera species are present in the world. However, there are
many species yet to be discovered and named, especially in tropical regions.
There are almost 3,600 species recorded in the United States and Canada.
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Habitats
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Most species of Hemiptera are terrestrial, living on land, but many are
aquatic, living their entire life in water. Some species are considered
semi-aquatic because they live at the edge of water or on the surface of
the water, but these insects cannot survive under the water. Water striders
in the genus Halobates live in the open ocean, skating on the top of water far
from any land. The depressions made on the water's surface can be seen in the
photograph of this water strider. More information on aquatic and semiaquatic
Hemiptera may be found at
Aquatic and Semiaquatic Hemiptera.
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Form and Function
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Adult hemipterans range in size from four hundredths of an inch
to more than three inches long. They can be either soft bodied
or hard bodied. Their shapes are often oval and somewhat
flattened or long and cylindrical. Although most true bugs are
dark colored, many have patterns of brilliant greens, reds,
blues, and yellows. Bright colors are common in Hemiptera.
Insects such as stink bugs (which can emit chemicals from scent
glands located on the insect's thorax) advertise with their
bright colors that they are distasteful.
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Most adult hemipterans have two pairs of wings, but some
have very short wings or are wingless. The forewing is
thickened and leathery at the base and membranous at the
tip, whereas the hindwing is entirely membranous. The wings
are held flat over the body with the tips overlapping, outlining
a triangle on their back.
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The mouthparts of Hemiptera include an elongated beak that is used for piercing
and sucking. The beak encloses two channels (each a hollow tube): one
carries saliva to the host tissue, and one sucks up the liquid food.
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The antennae are usually slender and composed of four or five segments. The
legs are usually slender, but there are many exceptions. Some have raptorial
front legs, legs adapted for catching prey; some have enlarged hind legs
(femora) for jumping, and some have the middle or hind legs modified for
swimming.
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Nymphs differ from adults in lacking fully developed wings and the triangle on
the back. As the nymph matures, small wing pads on the thorax grow with each
molt until the wings are fully formed in the adult stage.
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Life Cycle
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Hemiptera have incomplete metamorphosis (egg-nymph-adult). The eggs may be
laid singly in plant tissue or tight crevices, in a large mass on leaves or
stems, dropped at random on the ground, or even carried around on the back of
the male. Eggs often have bizarre forms. The eggs of some Pentatomidae
resemble small barrels complete with hoops.
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After hatching from the egg, the nymph passes through five instars (growth
stages). The nymph molts at the end of each instar, becoming an adult after
the final molt. Adults often are the stage that live through the winter, and
they begin a new generation in the spring.
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Life cycles of most Hemiptera are relatively long, and many
species require a year to pass a single generation. However,
bed bugs have been known to have from one to 12 generations in
a year.
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Food and Feeding Habits
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A plant-feeding true bug pierces the leaf, stem, or other plant part with its
beak and sucks the plant juices up its food channel. Many bugs feed only
on a certain kind of plant; they are said to be "host-specific." In
addition to plants, some Hemiptera feed on algae and fungi.
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The hosts of predaceous Hemiptera range from small insect eggs to fish, birds,
and armadillos. However, most predators feed on insects, especially soft
bodied stages like caterpillars. Water striders prey on insects that fall
onto the surface of the water. Bed bugs (Cimicidae) feed on the blood of
mammals and birds. Assassin bugs and kissing bugs (Reduviidae) include
some species that also are blood suckers.
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Natural Enemies
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Hemiptera are attacked by many predators, including birds, fish, other insects,
and spiders. Predators even include other Hemiptera, especially stink bugs,
assassin bugs, and minute pirate bugs. Some wasps capture and paralyze
Hemiptera, storing them in their nest to serve as food for their own young.
Other wasps and some flies are parasites of Hemiptera. The larvae of these
wasps and flies live inside the egg, nymph, or adult, eventually killing the
bug.
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Olympic Feats and Other Strange Facts
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A giant water bug (Belostomatidae) has been observed killing an eight inch
long snake.
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Some Hemiptera females sit on their eggs until they hatch. After hatching,
the young nymphs will hide under the mother bug if a predator comes near.
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Some water striders (Gerridae) and water boatmen (Corixidae) can make sound by
rubbing their front legs together or against their bodies.
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Males of some giant water bugs carry the eggs on their backs until they hatch.
Females hold the males and cement the eggs to them.
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Milkweed bugs (Lygaeidae) are among the world's first parachutists. They
often obtain a lift to a new area by clinging to the wind-blown seeds of
milkweed.
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Backswimmers (Notonectidae) get their name from the fact that they swim upside
down on their backs, unlike any other insect. Some can stay under water for
more than an hour.
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Bed bugs were once recommended for curing some infections. If one ate seven
bed bugs with beans, people believed this would help relieve some kinds of
fever.
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Bed bugs have special bacteria in their abdomen to supply B-group vitamins,
which are absent in blood.
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Adult bed bugs have been known to live for a year without feeding.
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A hormone from a gland near the brain, which is necessary for molting in
insects, was first discovered in an assassin bug, Rhodnius. By cutting off
their heads and sealing the open wounds with wax, Professor Vincent
Wigglesworth found that the nymphs would live as long as an year without
molting.
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Bat bugs live on the bodies of bats, feeding on their blood. In the United
States, these bugs occur only in Texas and California.
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The Good and The Bad
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Many Hemiptera are considered beneficial to man because they help reduce
populations of certain pest species. There are species of stink bugs, minute
pirate bugs, damsel bugs, and assassin bugs that are predaceous on pests.
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Pests of vegetables and fruits include the tarnished plant bug (Lygus
lineolaris, Miridae), garden fleahoppers (Halticus spp., Miridae), and
squash bug (Anasa tristis, Coreidae). The chinch bug (Blissus
leucopterus, Blissidae) is a serious pest of wheat, corn, and other grasses. Other pests include the cotton stainer (Dysdercus spp., Pyrrhocoridae), harlequin bug, (Murgantia histrionica, Pentatomidae), and the
southern green stink bug, Nezara viridula.
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Assassin bugs probably have the most painful bites caused by insects. Some
South American species of assassin bugs also transmit a parasite to man that
causes Chagas disease. Bites of bed bugs are irritating, although not
painful, but these insects are not known to transmit any parasites that cause
diseases.
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Taxonomy
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Families of North American Hemiptera
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Terrestrial Bugs
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Acanthosomatidae (Acanthosomatid stink bugs)
Alydidae (Broad Headed Bugs)
Anthocoridae (Minute Pirate Bugs)
Aradidae (Flat Bugs)
Berytidae (Stilt Bugs)
Blissidae (Chinch Bugs)
Ceratocombidae (Ceratocombid Bugs)
Cimicidae (Bed Bugs)
Coreidae (Squash Bugs or Leaf-footed Bugs)
Cydnidae (Burrower Bugs)
Dipsocoridae (Jumping Ground Bugs)
Enicocephalidae (Unique-headed Bugs)
Leptopodidae (Spiny Shore Bugs)
Lygaeidae (Seed Bugs)
Microphysidae (Minute Bladder Bugs)
Miridae (Plant Bugs)
Nabidae (Damsel Bugs)
Pentatomidae (Stink Bugs)
Phymatidae (Ambush Bugs)
Piesmatidae (Ash-gray Leaf Bugs)
Polyctenidae (Bat Bugs)
Pyrrhocoridae (Cotton Stainers)
Reduviidae (Assassin and Thread-legged Bugs)
Rhopalidae (Scentless Plant Bugs)
Schizopteridae (Jumping Soil Bugs)
Thaumastocoridae (Royal Palm Bugs)
Thyreocoridae (Negro Bugs)
Tingidae (Lace Bugs)
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Aquatic and Semi-aquatic Bugs
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Belostomatidae (Giant Water Bugs)
Corixidae (Waterboatmen)
Gelastocoridae (Toad Bugs)
Gerridae (Water Striders)
Hydrometridae (Marsh Treaders)
Hebridae (Velvet Water Bugs)
Leptopodidae (Spiny-legged Bugs)
Macroveliidae (Macroveliid Shore Bugs)
Mesoviliidae (Water Treader)
Naucoridae (Creeping Water Bugs)
Nepidae (Waterscorpions)
Notonectidae (Backswimmers)
Ochteridae (Velvety Shore Bugs)
Pleidae (Pigmy Backswimmer)
Saldidae (Shore Bugs)
Veliidae (Smaller Water Striders)
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Selected References
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Dolling, W.R. The Hemiptera. Oxford University Press, 1991.
Hutchins, R.E. The Bug Clan. New York, Dodd, Mead, & Co., 1973.
Slater, J.A. and R.M. Baranowski. How to Know the True Bugs (Hemiptera - Heteroptera). Pictured Key Nature Series. Dubuque, Iowa, Wm. C. Brown Co., 1978.
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Links
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For an extensive list of Hemiptera Web sites, go to the Links Component of the module.
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Picture Credits
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Used with permission from
Department of Entomology
University of Nebraska-Lincoln
Harlequin Bug (Murgantia histronica)
Adults and Nymphs of Chinch Bug
Human Bed Bug (Cimex lectularius)
Dr. Ross E. Hutchins (Deceased)
Mississippi State University Entomology Museum
Water Strider
Hemiptera Forewing and Hindwing
Eggs of Harlequin Bug with Carpenter Ant
Giant Water Bug Killing Snake
Giant Water Bugs, Male with Eggs
Backswimmer Getting Air on Water Surface
Wheel Bug with Biting Proboscis
D. F. Young
Tarnished Plant Bug (Lygus lineolaris)
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