Glomeris marginata
Encyclopedia
Glomeris marginata is a common Europe
an species
of pill millipede
. It is a short millipede, rounded in cross-section, which is capable of rolling itself up into a ball when disturbed. This behaviour is also found in the pill woodlouse Armadillidium
, with which G. marginata is often confused.
and Scandinavia
to Spain
and Italy
. In the British Isles
, it is found in all areas south of the Central Belt
of Scotland
.
Glomeris marginata grows up to 20 millimetre (0.78740157480315 in) long and 8 mm (0.31496062992126 in) wide, and is covered by twelve black dorsal plates with white rims. Each segment except those at the front and back bears two pairs of legs, with around 18 pairs in total. This distinguishes pill millipedes from pill woodlice, both of which are called "pillbugs" — woodlice have 7 pairs of walking legs
, one per body segment, while millipedes have more pairs, and with two pairs to each apparent body segment.
When rolled into a ball, G. marginata can be distinguished from a rolled–up pill woodlouse by the asymmetrical ball it rolls into; pill woodlice roll into much more perfect spheres. The cuticle is also darker and shinier, and the antennae
are shorter. The head and tail of a woodlouse have a greater number of small plates, while the head of Glomeris is protected by a single large shield, and it lacks the uropods of woodlice at the read end. Although usually black, red, yellow and brown individuals do occasionally occur.
Glomeris marginata lives in leaf litter as well as in grass and under stones, with a preference for calcareous
soils. In domestic gardens, they are most frequent along hedgerows and at the bases of old walls, where the mortar
has started to crumble, leaching lime
into the soil. It is less prone to desiccation
than other millipedes and can be found in the open, even in sunny weather, although they are more active at night and prefer more humid areas. G. marginata feeds on old, rotting leaves, despite the higher nutrient content of freshly–fallen leaves, and G. marginata can be responsible for recycling
a significant proportion of the nutrient
s in the leaf litter.
Predators of Glomeris marginata are reported to include the starling
, the common toad
, the woodlouse spider
, and hedgehogs. As well as rolling up into a ball for protection, G. marginata produces noxious chemicals to ward off potential predators, as many millipedes do. One to eight drops of a viscid fluid are secreted, containing quinazolinone
alkaloid
s, dissolved in a watery protein matrix. These chemicals act as antifeedants and toxin
s to spider
s, insect
s and vertebrate
s, and the fluid is sticky enough to entrap the legs of ant
s. Having completely discharged these chemical defences, it can take up to four months for the millipede to replenish their supplies.
and are capable of producing a pheromone
which attracts females, although this is only believed to be effective over short distances. They then transfer sperm
to the female using their gonopods, specially modified legs. After fertilisation
, the females lay 70–80 eggs, each about 1 mm long, and each wrapped singly in a capsule of digested earth. The eggs hatch after a period of about two months, with the duration depending on factors including temperature
. Development lasts for up to three years, and involves nine moults
, following which moults occur periodically as adults. Females are fertile for several years, and can produce six broods over their lifetime, which can be up to eleven years.
Europe
Europe 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 watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
an species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of pill millipede
Pill millipede
Pill millipedes make up two orders of millipedes, often grouped together into a single superorder, Oniscomorpha. The name Oniscomorpha refers to the resemblance of pill millipedes to certain woodlice, namely the pillbugs of the family Armadillidiidae, also called "potato bugs", "doodlebugs", or...
. It is a short millipede, rounded in cross-section, which is capable of rolling itself up into a ball when disturbed. This behaviour is also found in the pill woodlouse Armadillidium
Armadillidium
Armadillidium is a genus of the small terrestrial crustacean known as the woodlouse. Armadillidium are also commonly known as pill woodlice, pill bugs or roly-poly, and are often confused with pill millipedes such as Glomeris marginata. They are characterised by their ability to roll into a ball...
, with which G. marginata is often confused.
Distribution
Glomeris marginata is found throughout central and north-western Europe, from PolandPoland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
and Scandinavia
Scandinavia
Scandinavia is a cultural, historical and ethno-linguistic region in northern Europe that includes the three kingdoms of Denmark, Norway and Sweden, characterized by their common ethno-cultural heritage and language. Modern Norway and Sweden proper are situated on the Scandinavian Peninsula,...
to Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
and Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
. In the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...
, it is found in all areas south of the Central Belt
Central Belt
The Central Belt of Scotland is a common term used to describe the area of highest population density within Scotland. Despite the name, it is not geographically central but is nevertheless situated at the 'waist' of Scotland on a conventional map and the term 'central' is used in many local...
of Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
.
Description
Arthropod leg
The 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 ,...
, one per body segment, while millipedes have more pairs, and with two pairs to each apparent body segment.
When rolled into a ball, G. marginata can be distinguished from a rolled–up pill woodlouse by the asymmetrical ball it rolls into; pill woodlice roll into much more perfect spheres. The cuticle is also darker and shinier, and the antennae
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
are shorter. The head and tail of a woodlouse have a greater number of small plates, while the head of Glomeris is protected by a single large shield, and it lacks the uropods of woodlice at the read end. Although usually black, red, yellow and brown individuals do occasionally occur.
Ecology
Calcareous
Calcareous is an adjective meaning mostly or partly composed of calcium carbonate, in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines.-In zoology:...
soils. In domestic gardens, they are most frequent along hedgerows and at the bases of old walls, where the mortar
Mortar (masonry)
Mortar is a workable paste used to bind construction blocks together and fill the gaps between them. The blocks may be stone, brick, cinder blocks, etc. Mortar becomes hard when it sets, resulting in a rigid aggregate structure. Modern mortars are typically made from a mixture of sand, a binder...
has started to crumble, leaching lime
Lime (mineral)
Lime is a general term for calcium-containing inorganic materials, in which carbonates, oxides and hydroxides predominate. Strictly speaking, lime is calcium oxide or calcium hydroxide. It is also the name for a single mineral of the CaO composition, occurring very rarely...
into the soil. It is less prone to desiccation
Desiccation
Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic substance that induces or sustains such a state in its local vicinity in a moderately sealed container.-Science:...
than other millipedes and can be found in the open, even in sunny weather, although they are more active at night and prefer more humid areas. G. marginata feeds on old, rotting leaves, despite the higher nutrient content of freshly–fallen leaves, and G. marginata can be responsible for recycling
Biogeochemical cycle
In ecology and Earth science, a biogeochemical cycle or substance turnover or cycling of substances is a pathway by which a chemical element or molecule moves through both biotic and abiotic compartments of Earth. A cycle is a series of change which comes back to the starting point and which can...
a significant proportion of the nutrient
Nutrient
A nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment. They are used to build and repair tissues, regulate body processes and are converted to and used as energy...
s in the leaf litter.
Predators of Glomeris marginata are reported to include the starling
European Starling
The Common Starling , also known as the European Starling or just Starling, is a passerine bird in the family Sturnidae.This species of starling is native to most of temperate Europe and western Asia...
, the common toad
Common Toad
The common toad or European toad is an amphibian widespread throughout Europe, with the exception of Iceland, Ireland and some Mediterranean islands...
, the woodlouse spider
Woodlouse spider
The woodlouse spider is a species of spider that preys exclusively upon woodlice.Other common names refer to variations on the common name of its prey...
, and hedgehogs. As well as rolling up into a ball for protection, G. marginata produces noxious chemicals to ward off potential predators, as many millipedes do. One to eight drops of a viscid fluid are secreted, containing quinazolinone
Quinazoline
Quinazoline is a compound made up of two fused six-membered simple aromatic rings, a benzene ring and a pyrimidine ring. Its chemical formula is C8H6N2. Quinazoline is yellow and crystalline...
alkaloid
Alkaloid
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...
s, dissolved in a watery protein matrix. These chemicals act as antifeedants and toxin
Toxin
A toxin is a poisonous substance produced within living cells or organisms; man-made substances created by artificial processes are thus excluded...
s to spider
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with 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, insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s and vertebrate
Vertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
s, and the fluid is sticky enough to entrap the legs of ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, 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. More than...
s. Having completely discharged these chemical defences, it can take up to four months for the millipede to replenish their supplies.
Reproduction and life cycle
Breeding takes place cyclically in spring and summer. Male G. marginata stridulateStridulation
Stridulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects, but other animals are known to do this as well, such as a number of species of fishes, snakes and spiders...
and are capable of producing a pheromone
Pheromone
A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behavior of the receiving individual...
which attracts females, although this is only believed to be effective over short distances. They then transfer sperm
Sperm
The term sperm is derived from the Greek word sperma and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell...
to the female using their gonopods, specially modified legs. After fertilisation
Fertilisation
Fertilisation is the fusion of gametes to produce a new organism. In animals, the process involves the fusion of an ovum with a sperm, which eventually leads to the development of an embryo...
, the females lay 70–80 eggs, each about 1 mm long, and each wrapped singly in a capsule of digested earth. The eggs hatch after a period of about two months, with the duration depending on factors including temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
. Development lasts for up to three years, and involves nine moults
Ecdysis
Ecdysis is the moulting of the cuticula in many invertebrates. This process of moulting is the defining feature of the clade Ecdysozoa, comprising the arthropods, nematodes, velvet worms, horsehair worms, rotifers, tardigrades and Cephalorhyncha...
, following which moults occur periodically as adults. Females are fertile for several years, and can produce six broods over their lifetime, which can be up to eleven years.