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The
Diversity of The World of Life
Arthropods
(Arthropoda)
Myriapods
(Myriapoda)
Representatives
Millipedes
(Diplopoda)
Pauropods
(Pauropoda)
Centipedes
(Chilopoda)
Symphylans
(Symphyla)
Biology
APPROXIMATE NUMBER OF KNOWN SPECIES WORLDWIDE
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DESCRIPTION
Millipedes are typically dark-colored and 1/2" to 4" long full-grown,
although some species grow over a foot long.
The body is wormlike and usually cylindrical.
The head bears one pair of antennae, one pair of jaw-like
"mandibles", and several other mouthparts. Most of
the usually 30 or more segments of the trunk each have two pairs of legs
(each segment is typically a "double" segment, a pair fused in
evolution).
Stink glands are often present.
Centipedes are typically pale to colorful or dark, and a
few mm to 6" long.
The body is wormlike and usually "dorso-ventrally"
flattened (flattened from top-to-bottom).
The head bears one pair of antennae, one pair of mandibles, and two pairs
of "maxillae" -- one pair jaw-like, the other
finger-like. The first segment of the trunk behind the head bears a
pair of poison claws; behind that, there are 15 or more pairs of legs, one pair per segment of the
trunk.
The legs on either side of the body move alternately, not in unison.
Centipedes
readily run-down their prey by means of their
often long, "sure footed" legs, borne on the often overlapping,
"wobble free" segments of their body.
METAMORPHOSIS
The
hatchlings of millipedes look like small adults but have just a few body segments and
three pairs of legs: The
remaining segments and legs appear during the molts to the adult stage.
The young of centipedes typically look like small adults, although sometimes with fewer legs.
The female wraps her body around her eggs and developing young, to
protect them, as from the males.
HABITATS
Millipedes,
which avoid light, are active at night and are usually found in such damp
places as under stones, boards, logs, and leaves and in soil, rotting
wood, moss, and damp places indoors.
Although they move slowly, millipedes readily push their typically
cylindrical body through debris by means of their numerous legs, borne on the
strong "double" segments of their body.
Centipedes
usually come out at night and hide, during the daytime, in such sheltered,
moist (but not too wet) spots as under stones, bark, leaves, or debris; in
litter, rotten wood, and soil; and even in damp garages, basements, sinks,
and bathtubs.
FOODS
Although a
few prey on other invertebrates and although a few may eat seedlings and
feed on the succulent, sweet roots and shoots of even larger plants, most
millipedes are scavengers.
Centipedes
prey on small animals, usually such arthropods as spiders or insects, as found by sense of smell and perhaps touch.
Most centipedes can run-down their prey very quickly.
The fastest centipedes have the fewest legs and also have curving, overlapping plates
on their back, which keep the body from
weaving from side-to-side while running.
Some centipedes capture their prey with silk.
All centipedes bite into and paralyze their prey, by means of a
pair of poison claws.
DAMAGES/BENEFITS
Although
a few millipedes do much harm to living plants in gardens and greenhouses,
directly (by chewing on plants) or indirectly (by allowing fungal diseases
into plants through feeding wounds), most millipedes are valuable
decomposers of waste materials, which can fertilize the soil. Note,
too, that millipedes do not consume foods in households; they do not damage
structures; and unlike some centipedes, they cannot bite us human
beings.
Although
even a small centipede's bite can be painful, most people are endangered only by the bite of large
species of centipedes, native to the
warm regions of the world. In
homes and other buildings, centipedes do not damage foods or other
household items but do prey on insects that are usually pests.
Arthropods
(Arthropoda)
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