Scutigera coleoptrata (one of several species commonly known as the
house centipedeScutigera coleoptrata , is a yellowish-grey centipede with 15 pairs of legs. Originally endemic to the Mediterranean region, the species has spread to other parts of the world, where it usually lives in human homes...
or
hair creature), is a yellowish-grey
centipedeCentipedes are arthropods belonging to the class Chilopoda and the Subphylum Myriapoda. They are elongated metameric animals with one pair of legs per body segment. A key trait uniting this group is a pair of venom claws or forcipules formed from a modified first appendage...
with 15 pairs of legs. Originally endemic to the Mediterranean region, the species has spread to other parts of the world, where it usually lives in human homes. It is an
insectivoreAn insectivore is a type of carnivore with a diet that consists chiefly of insects and similar small creatures.Although individually small, insects exist in enormous numbers and make up a very large part of the animal biomass in almost all non-marine environments...
; it kills and eats
arthropodAn arthropod is an invertebrate that has an exoskeleton , a segmented body, and jointed attachments called appendages. Arthropods are animals belonging to the Phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s such as
insectInsects are arthropods, having a hard exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae. They are the most diverse group of animals on the planet and include more than a million species that are already described. Insects represent more than half of all...
s and
arachnidArachnids are a class of joint-legged invertebrate animals in the subphylum Chelicerata. All arachnids have eight legs, although in some species the front pair may convert to a sensory function. The term is derived from the Greek word , meaning "spider".Most arachnids are terrestrial...
s.
Morphology
S. coleoptrata is to in length and has up to 15 pairs of remarkably long
legThe arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments are of Latin origin, and may be confused with terms for bones: coxa , trochanter , femur, tibia, tarsus, ischium, metatarsus, carpus, dactylus The arthropod...
s. These delicate legs are attached to a rigid body. This enables it to reach surprising speeds of up to per second (0.9 mph/1.46 kph) running across floors, up walls and along ceilings. Its body is yellowish-grey and has three dark-colored
dorsalIn anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...
stripes running down its length; the legs also have dark stripes. Unlike most other centipedes, house centipedes and their close relatives have well-developed, faceted eyes. S. coleoptrata has developed automimicry in that its hind legs present the appearance of antennae. While it is at rest it is not easy to tell its front from its back.
Reproduction and development
House centipedes lay their eggs in
springSpring is one of the four temperate seasons, the transition period between winter and summer. Its days are close to twelve hours long with increasing day length, as it occurs near the time of an equinox. In the Northern Hemisphere, spring runs from March into May, and in the Southern Hemisphere it...
. In a laboratory experiment of 24 house centipedes, an average of 63 and a maximum of 151 eggs were laid. Like in many other arthropods, the larvae look like miniature versions of the adult, albeit with fewer legs. Young centipedes have four pairs of legs when they are hatched. They gain a new pair with the first
moltingEcdysis is the moulting of the cuticula in arthropods and related groups . Since the cuticula of these animals is also the skeletal support of the body and is inelastic, it is shed during growth and a new, larger covering is formed...
, and two pairs with every of their five subsequent moltings. Adults with 15 pairs of legs retain that number through three more molting stages (sequence 4-5-7-11-13-15-15-15-15 pairs). They live anywhere from three to seven years, depending on the environment. They can start breeding in their third year. For mating the male and female circle around each other. They initiate contact with their antennae. The male deposits his sperm on the ground and the female then uses it to fertilize her eggs. Some report that the eggs are deposited in the ground and covered with plant matter. Scutigera coleoptrata was observed providing parental care. The female lies on her side cradling her clutch of eggs, and later the larvae. This behavior was reported to proceed for several weeks. The female applies an
antifungalA fungus is any member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. The Fungi are classified as a kingdom that is separate from plants, animals and bacteria...
secretion by mouthing the eggs.
Behavior and ecology
House centipedes feed on
spiderSpiders are air-breathing chelicerate arthropods that have eight legs, and chelicerae modified into fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
s,
bedbugThe bedbug is an insect of the family Cimicidae that lives by hematophagy - feeding on the blood of humans and other warm-blooded hosts. Its name comes from its preferred habitat: mattresses, sofas, and other furniture...
s,
termiteThe termites are a group of eusocial insects usually classified at the taxonomic rank of order Isoptera . Along with ants and some bees and wasps which are all placed in the separate order Hymenoptera, termites divide labour among gender lines, produce overlapping generations and take care of...
s,
cockroachCockroaches are insects of the order Blattaria. This name derives from the Latin name for the insect, Blatta....
es,
silverfishLepisma saccharina is a small, wingless insect typically measuring from a half to one inch...
,
antAnts are social insects of the family Formicidae , and along with the related wasps and bees, they belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants...
s, and other household arthropods. They administer venom through
modified legsForcipules are a unique feature found only in centipedes and in no other taxae of arthropods. The forcipules are modifications of the first set of legs, making them into pincer-like appendages, and are always found just behind the head. These limbs function as a set of jaws, and are used for...
. These are not part of their
mandiblesInsect mandibles are a pair of appendages near the insect’s mouth, and the most anterior of the three pairs of oral appendages . Their function is typically to grasp, crush, or cut the insect’s food, or to defend against predators or rivals...
, so strictly speaking they
sting-Biology:* Stinger, an organ or body part found in various animals that usually delivers some kind of venom.* Stinger , a minor neurological injury suffered by athletes.-Sports and entertainment:...
rather than
biteA bite is a wound received from the mouth of an animal, including humans. Animals may bite in self-defense, in an attempt to predate food, as well as part of normal interactions. Other bite attacks may be apparently unprovoked...
. They are mostly nocturnal hunters. Despite their developed eyes they seem to rely mostly on their antennae when hunting. Their
antennaeAntennae in biology have historically been paired appendages used for sensing in arthropods and crustaceans. More recently, the term has also been applied to cilium structures present in many cell types of eukaryotes....
are
sensitiveIn a sensory system, a sensory receptor is a sensory nerve ending that recognizes a stimulus in the internal or external environment of an organism...
to both smells and tactile information. They use both their mandibles and their legs for holding prey. This way they can deal with several small insects at the same time. To capture prey they either jump onto it or use their legs in a technique described as "lassoing". Using their legs to beat prey has also been described. In a feeding study,
S. coleoptrata showed the ability to distinguish between possible prey. They avoided dangerous insects. They also adapted their feeding pattern to the hazard the prey might pose to them. For
waspThe term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their numbers,...
s, they retreated after applying the venom to give it time to take effect. When the centipede is in danger of becoming prey itself, it can detach any legs that have become trapped.
Habitat
Outdoors, house centipedes prefer to live in cool, damp places. Centipede respiratory systems do not provide any mechanism for shutting the
spiracleSpiracles are small openings on the surface of some animals that usually lead to respiratory systems.In elasmobranchs , a spiracle is found behind each eye, and is often used to pump water through the gills while the animal is at rest .-Spiracles in insects:Insects and some more advanced spiders...
s. That is why they need an environment that protects them from dehydration and excessive cold. Most live outside, primarily under large rocks, piles of wood and especially in compost piles. Within the home, these centipedes are found in almost any part of the house. Most commonly, they are encountered in basements, bathrooms and lavatories, that tend to be humid, but they can also be found in drier places like offices, bedrooms and dining rooms. The greatest likelihood of encountering them is in
springSpring is one of the four temperate seasons, the transition period between winter and summer. Its days are close to twelve hours long with increasing day length, as it occurs near the time of an equinox. In the Northern Hemisphere, spring runs from March into May, and in the Southern Hemisphere it...
, when they come out because the weather gets warmer, and in
autumn/fallAutumn is one of the four temperate seasons. Autumn marks the transition from summer into winter, usually in March or September when the arrival of night becomes noticeably earlier.The equinoxes might be expected to be in the middle of their seasons, but temperature lag Autumn (also known as...
, when the cooling weather forces them to find shelter in human habitats.
Distribution
Scutigera coleoptrata is indigenous to the Mediterranean region, but it has spread through much of
EuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally divided from Asia to its east by the water divide of the Ural Mountains, the Ural River, the Caspian Sea, the Caucasus Mountains , and the Black Sea to the southeast...
,
AsiaAsia is the world's largest and most populous continent, located in the eastern and northern hemispheres. It covers 8.6% of the earth's total surface area and with approximately 4 billion people, it hosts 60% of the world's current human population.Asia is traditionally defined as part of the...
, and
North AmericaNorth America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...
. It is thought to have first been introduced in America in
MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
and
GuatemalaGuatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast. Its size is just under 110,000 km² with an estimated population...
. In the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
, it has spread from the southern states. It reached
PennsylvaniaThe Commonwealth of Pennsylvania , often colloquially referred to as PA by natives and Northeasterners, is a state located in the Northeastern and Middle Atlantic regions of the United States...
in 1849,
New YorkNew York is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous. The state is bordered by New Jersey and Pennsylvania to the south, and Connecticut, Massachusetts and Vermont to the east...
in 1885, and
MassachusettsThe Commonwealth of Massachusetts is a state in the New England region of the northeastern United States. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. Most of its population of...
about 1890,
West VirginiaWest Virginia is a state in the Appalachian and Mid-Atlantic regions of the United States, bordered by Virginia to the southeast, Kentucky to the southwest, Ohio to the northwest, and Pennsylvania and Maryland to the northeast...
and its distribution now extends westward to the
CaliforniaCalifornia is the most populous state in the United States, and the third largest by area. California is the second most populous sub-national entity in the Americas, behind only São Paulo, Brazil...
coast and reaches north into
CanadaCanada is a country occupying most of northern North America, extending from the Atlantic Ocean in the east to the Pacific Ocean in the west and northward into the Arctic Ocean...
(Lewis 1981). In
South AfricaThe Republic of South Africa is a country located at the southern tip of Africa, with a coastline on the Atlantic and Indian Oceans. To the north lie Namibia, Botswana and Zimbabwe, to the east are Mozambique and Swaziland, while Lesotho is an independent country surrounded by South Africa.Modern...
, they have been found in the
Western CapeThe Western Cape is a province in the south west of South Africa. The capital is Cape Town. Prior to 1994, the region that now forms the Western Cape was part of the much larger Cape Province...
, in and around Cape Town (sightings have been reported in
PinelandsThe "garden city" suburb of Pinelands is located on the edge of the southern suburbs of Cape Town in South Africa and is known for its large thatched houses. The suburb is primarily residential and is often praised for its peacefulness and abundance of trees...
and
Gordon's BayGordon's Bay is a harbour town in the Western Cape province of South Africa, close to Strand. It is situated on the northeastern corner of False Bay about 50 km from Cape Town to the south of the N2 national road and is named after Robert Jacob Gordon , the Dutch explorer of Scottish descent...
) and also in
KwaZulu-NatalKwaZulu-Natal is a province of South Africa. Prior to 1994 the territory now known as KwaZulu-Natal was made up of the province of Natal and all pieces of territory that made up the homeland of KwaZulu....
, in the city of
PietermaritzburgPietermaritzburg is the capital and second largest city of the province of KwaZulu-Natal in South Africa. It was founded in 1838. Its "purist" Zulu name is umGungundlovu, as seen in the name of its municipality, although it is popularly called Maritzburg in English and Zulu alike, and abbreviated PMB...
. In Japan, these creatures are referred to as
gejigeji. They have also been found in eastern and south-eastern
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the continental mainland , the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans...
, from
SydneySydney is the largest city in Australia, and the state capital of New South Wales. Sydney has a metropolitan area population of approximately 4.34 million and an area of approximately 12,000 square kilometres. Its inhabitants are called Sydneysiders, and Sydney is often called "the Harbour City"...
to
TasmaniaTasmania is an Australian island and state. It is located south of the eastern side of the continent, from which it is separated by Bass Strait. The state includes the island of Tasmania – the 26th largest island in the world – and the surrounding islands. The state has a population of 500,000 ,...
as well as in
New ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses , and numerous smaller islands, most notably Stewart Island/Rakiura and the Chatham Islands. The indigenous Māori named New Zealand Aotearoa, commonly translated as The Land of the Long White Cloud...
.
Biological details
Scutigera coleoptrata's faceted eyes are sensitive to daylight as well as very sensitive to ultraviolet light. They were shown to be able to visually distinguish between different mutations of
fruit fliesDrosophila melanogaster is a species of Diptera, or the order of flies, in the family Drosophilidae. The species is commonly known as the common fruit fly or vinegar fly. Starting from Charles W...
. How this ability fits with its nocturnal lifestyle and underground natural habitat is still under study. They do not instantly change direction when light is suddenly shone at them, but retreat to a darker hiding spot.
Some of the plates covering the body segments fused and became smaller during the evolution to S. coleoptrata's current state. The resulting mismatch between body segments and (
tergitesA tergum is the dorsal portion of an arthropod segment other than the head. The anterior edge is called the base and posterior edge is called the apex or margin. A given tergum may be divided into several plates, called tergites...
) is the cause for this centipede's rigid body.
Relation between body segments and dorsal plates (TergitesA tergum is the dorsal portion of an arthropod segment other than the head. The anterior edge is called the base and posterior edge is called the apex or margin. A given tergum may be divided into several plates, called tergites...
) and leg pairs
| Tergite |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
| Segments |
1 |
2 |
3, 4 |
5, 6 |
7, 8, 9 |
10, 11 |
12, 13 |
14, 15 |
16 |
17 |
18
(telson) |
| Leg pairs |
Forcipules |
1 |
2, 3 |
4, 5 |
6, 7, 8 |
9, 10 |
11, 12 |
13, 14 |
15 (antenna-like snare legs) |
(gonopod) |
(anus) |
Tergites 10 and 11 are not fully developed and segment 18 does not have a sternite. This model deviates from descriptions by Lewis who identified only 7 tergites and 15 segments.
Another feature that sets S. coleoptrata apart from other centipedes is that their
hemolymphHemolymph or haemolymph is the blood analogue used by all arthropods and most mollusks that have an open circulatory system.In these animals there is no distinction between blood and interstitial fluid. The liquid fills all of the interior of the body and surrounds all cells...
was found to contain
proteins for transporting oxygenHemocyanins are respiratory proteins in the form of metalloproteins containing two copper atoms that reversibly bind a single oxygen molecule . Oxygenation causes a color change between the colorless Cu deoxygenated form and the blue Cu oxygenated form...
.
The mitochondrial
genomeIn modern molecular biology the genome refers to all of its hereditary information encoded in DNA .The genome includes both the genes and the non-coding sequences of the DNA. The term was adapted in 1920 by Hans Winkler, Professor of Botany at the University of Hamburg, Germany...
of Scutigera coleoptrata has been sequenced (please see
External links). This opened up discussions on the taxonomy and phylogeny of this and related species.
Interaction with humans
Unlike its shorter-legged but much larger tropical cousins,
S. coleoptrata can live its entire life inside a building, usually the ground levels of homes. They are generally considered harmless to humans. and other large mammals like dogs or cats. Bites are uncommon and most house centipedes are incapable of penetrating human skin.
Techniques for eliminating centipedes from homes include drying up the areas where they thrive, eliminating large indoor insect populations, sealing cracks in the walls, and seeking the assistance of an
exterminatorPest control refers to the regulation or management of a species defined as a pest, usually because it is perceived to be detrimental to a person's health, the ecology or the economy....
.
External links