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Centipedes and Millipedes
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Centipedes Centipedes belonging to Phylum Arthropda, are similar to millipedes.
Both are elongate and flattened, however, centipedes have only one pair of legs
per body segments and have 15 or more pairs of legs. A centipede's final pair of
legs is directed backwards and is different from the other legs. Antennae are
long and consist of 14 or more segments. Some centipedes have eyes while others
do not. Like millipedes, the centipede mouthparts are mandibles. They have two
pairs of maxillae with the second pair appearing leglike. A centipedes fist
segment has clawlike appendages that act as poisonous jaws.
Centipedes are generally found in unprotected areas such as in the soil or under
logs. They are quick and feed on insects, spiders, and other small animals. They
all possess the poisonous jaws which are used to paralyze their prey. Centipedes
also overwinter as adults and lay their eggs in the summer.
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Description
Centipedes or "hundred-leggers," are elongated, flattened animals,
bearing one pair of legs per body segment. The actual total number of
legs in most species is closer to 30 than to 100. Adult centipedes are
usually brownish and over 1 inch in length. The house
centipede, a species that commonly invades buildings, has long legs
that enable it to run rapidly. Unlike millipedes, centipedes never coil
up when disturbed.
Habitat and Importance
 Centipedes usually are found in damp, dark places,
such as under stones, leaf mulch, or logs. Indoors, centipedes may occur
in damp areas of basements, closets, or bathrooms, or anywhere in the
home where insects occur. During the day they hide in dark cracks and
crevices, coming out at night to search for insects to eat.
House centipedes are actually beneficial--they capture flies,
cockroaches, and other small household pests. They never damage plants
or household items.
Scolopendran centipede
Click to enlarge
When provoked, a few large kinds of centipedes can inflict a painful
bite that may cause localized swelling, discoloration, and numbness.
Life Cycle
Adult centipedes overwinter in secluded moist places.
Eggs are usually placed in damp soil in the spring and summer. Some
centipede species add segments and legs as they grow; others are born
with a complete set. Centipedes require 2 to 3 years to mature, and have
been known to live 6 years.
House Centipede
Control
Centipedes seldom need to be controlled unless they
become a nuisance in the home. Centipedes are predators and generally
play a beneficial role in the garden. Their activities should be
encouraged in the yard. Reductions in the number of household centipedes
occur when their food source--other household pests--is controlled.
Airing out damp places may help. Outdoors, centipede control is aided by
the removal of debris as recommended for millipedes. Although some
pesticides are labeled for controlling centipedes, their use is rarely
justified.
Centipede
stings often occur as the victim is putting on clothes or while in bed. They
usually release from the skin immediately, although there are reports of
tenacious attachments requiring removal with a noxious agent such as alcohol and
even surgery.
There have been a number of centipede envenomation cases reported worldwide
describing a benign, albeit painful, syndrome.
The most common scenario includes moderate to severe local symptoms associated
with mild systemic symptoms. Local symptoms include pain, erythema, edema,
lymphangitis/lymphadenitis, weakness, and paresthesias. Skin necrosis may occur
at the site of envenomation during the weeks following the sting, but rarely
becomes extensive and heals spontaneously. Systemic symptoms may include
anxiety, fever, dizziness, palpitations, and nausea. Excluding local skin
necrosis, findings usually resolve within 2 days without sequelae; however,
exceptions should be mentioned.
 No fatality
due to a centipede sting has ever been reported in the United States. The
contents of almost 1000 venom glands would be required for a fatal sting in an
average adult.
================================
 Centipedes are common arthropods with long,
flattened, segmented bodies with one pair of legs per segment. The house
centipede is up to 1 1/2 inches long and has 15 pairs of very long, slender
legs. Each leg is encircled by dark and white bands. The body is brown to
grayish-yellow and has three dark stripes on top.
Though house centipedes are found both indoors and
outdoors it is the occasional one on the bathroom or bedroom wall, or the
one accidentally trapped in the bathtub, sink, or lavatory that causes the
most concern. However, these locations are not where they normally
originate. Centipedes prefer to live in damp portions of basements, closets,
bathrooms, unexcavated areas under the house and beneath the bark of
firewood stored indoors. They do not come up through the drain pipes.
House centipedes feed on small insects, insect larvae, and
on spiders. Thus they are beneficial, though most homeowners take a
different point-of-view and consider them a nuisance. Technically, the house
centipede could bite, but it is considered harmless to people.
House centipede control consists of drying up and
cleaning, as much as possible, the areas that serve as habitat and food
source for centipedes. Residual insecticides can be applied to usual hiding
places such as crawl spaces, dark corners in basements, baseboard cracks and
crevices, openings in concrete slabs, and so forth. Centipedes
discovered outdoors should not be controlled. |
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Description
 Millipedes, or "thousand-leggers,"
are brownish, elongated, cylindrical to slightly flattened creatures,
with two (most common) or four pairs of tiny legs per body segment.
Millipedes don't really have a thousand legs; even the largest ones have
somewhat less than a hundred. When they walk, their legs move in an
undulating wavelike manner. Adult millipedes vary from 1/2 to 6 1/2
inches in length. When prodded or at rest, most millipedes curl up.
Click photo to
enlarge
Millipedes may be confused with wireworms because of their similar
shapes. Wireworms, however, are click beetle larvae, have only three
pairs of legs, and stay underneath the soil surface.
Habitat and Importance
Millipedes normally live in and feed on rotting leaves
and wood and other kinds of moist decaying plant matter. Generally,
their role is a beneficial one in helping to break down dead plant
matter. However, when they become numerous, they may damage sprouting
seeds, seedlings, or strawberries and other ripening fruits in contact
with the ground.
Sometimes individual millipedes wander from their moist living places
into homes, but they usually die quickly because of the dry conditions
and lack of food. Occasionally, large numbers of millipedes migrate,
often uphill, as their food supply dwindles or their living places
become either too wet or too dry. They may fall into swimming pools and
drown.
When disturbed they do not bite, but some species exude a defensive
liquid that can irritate skin or burn the eyes.
Life Cycle
Adult millipedes overwinter in the soil. Eggs are laid
in clutches beneath the soil surface.
The
young grow gradually in size, adding segments and legs as they
mature. They mature in 2 to 5 years and continue to live for several
years thereafter.
Control
Millipedes seldom need to be controlled. Keep in mind
that they do no damage indoors and pose no health hazard. Those that
stray indoors can be swept out or picked up with a vacuum cleaner.
Sealing cracks and other openings to the outside helps prevent them from
entering. Usually invasions are over within a few days.
Eliminating moist hiding places around the home will kill or
discourage millipedes. Outdoors, this includes removing rotting wood and
decaying grass and leaves from around the house's foundation. This also
eliminates millipede food sources. If there is excessive moisture in
subfloor crawl spaces or basements, take measures to dry out these
areas.
Application of insecticides is rarely justified for millipede
control.
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