The black garden ant (''Lasius niger''), also known as the common black ant, is a formicine

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of ...

, the type species of the subgenus ''

Lasius ''Lasius'' is a genus of formicine ants. The type species for this genus is the black garden ant, ''Lasius niger''. Other major members, which live in drier heathland, are the cornfield ant, '' L. neoniger'', and '' L. alienus''. Other species ...

'', which is found across

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

and in some parts of

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sou ...

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

and

Australasia Australasia is a region that comprises Australia, New Zealand and some neighbouring islands in the Pacific Ocean. The term is used in a number of different contexts, including geopolitically, physiogeographically, philologically, and ecologic ...

. The European species was split into two species; ''L. niger'', which are found in open areas; and ''L. platythorax'', which is found in

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

habitats. It is

monogynous This is a glossary of terms used in the descriptions of ants. A B D E F G H M N O P Q R S T U W See also ...

, meaning

colonies In modern parlance, a colony is a territory subject to a form of foreign rule. Though dominated by the foreign colonizers, colonies remain separate from the administration of the original country of the colonizers, the '' metropolitan state'' ...

contain a single

queen Queen or QUEEN may refer to: Monarchy * Queen regnant, a female monarch of a Kingdom ** List of queens regnant * Queen consort, the wife of a reigning king * Queen dowager, the widow of a king * Queen mother, a queen dowager who is the mother ...

. ''Lasius niger'' colonies can reach in size up to around 40,000 workers in rare cases, but 4,000–7,000 is around average. A ''Lasius niger'' queen can live for up to 29 years the longest recorded lifespan for any

eusocial Eusociality (from Greek εὖ ''eu'' "good" and social), the highest level of organization of sociality, is defined by the following characteristics: cooperative brood care (including care of offspring from other individuals), overlapping gen ...

insect. ''Lasius niger'' queens in the early stages of founding can have two to three other queens in the nest. They will tolerate each other until the first workers come, then it is most likely they will fight until one queen remains. Under laboratory conditions, workers can live at least 4 years. ''Lasius niger'' is host to a number of temporary social parasites of the ''Lasius mixtus'' group including '' Lasius mixtus'' and ''

Lasius umbratus ''Lasius umbratus'', colloquially known as the yellow shadow ant and yellow lawn ant, is a palearctic species of parasitic ant distributed across Eurasia and the Maghreb region of Africa. It was once thought that this species occurred in Nort ...

''.

Appearance

Life cycle

Mating flights

Ants mate on the wing, so "flying ants" are

alate Alate (Latin ''ālātus'', from ''āla'' (“wing”)) is an adjective and noun used in entomology and botany to refer to something that has wings or winglike structures. In entomology In entomology, "alate" usually refers to the winged form o ...

s (reproductive individuals), which includes males and

gyne The gyne (, from Greek γυνή, "woman") is the primary reproductive female caste of social insects (especially ants, wasps, and bees of order Hymenoptera, as well as termites). Gynes are those destined to become queens, whereas female workers ...

s (virgin queens). The mating (or nuptial) flights of ''Lasius niger'' usually occur around June to September throughout the species' range; in North America flights usually occur during the

autumn Autumn, also known as fall in American English and Canadian English, is one of the four temperate seasons on Earth. Outside the tropics, autumn marks the transition from summer to winter, in September ( Northern Hemisphere) or March ( ...

, whereas in Europe they generally take place during the hot

summer Summer is the hottest of the four temperate seasons, occurring after spring and before autumn. At or centred on the summer solstice, the earliest sunrise and latest sunset occurs, daylight hours are longest and dark hours are shortest, wit ...

months of July and August. Flights can contain thousands of winged males and females. Disparities between local weather conditions can cause nuptial flights to be out of phase amongst widespread populations of ''L. niger''. During long-lasting, hot summers, flights can take place simultaneously across the country, but overcast weather with local patches of sunshine results in a far less synchronized emergence of alates. Once the queens have mated they will land and discard their wings and begin to find a suitable place to dig a tunnel. Meanwhile, males generally only live for a day or two after the mating flights and will then die.

New nest

After removing her wings, a queen will move quickly to find moist ground, then start digging a tunnel. Once the tunnel has been completed, the queen will block the entrance and retreat to the bottom. Subsequently, she will dig out a small chamber. This will serve as the claustral chamber of the new colony. Generally, a queen will begin to lay eggs immediately after the construction of the chamber, and the eggs will hatch after 8–10 weeks. Until the eggs hatch and the larvae grow to maturity, a ''Lasius niger'' queen will not eat, relying on the protein of her wing muscles to be broken down and digested. In some cases, a ''Lasius niger'' queen may eat her own eggs in order to survive.

Egg to ant

''Lasius niger'', like other ants, have four stages of development: egg,

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in thei ...

, and adult. ''Lasius niger'' lay tiny, white, kidney-shaped eggs with a smooth sticky surface which helps them to be carried in a group instead of one by one. After hatching ''Lasius niger'' proceed onto the larva stage resembling tiny maggots. The larvae need to be fed by the queen (or workers in the case of an established colony) if they are to mature; as they feed the larvae grow, shedding their skin, doing so usually three times in total. With each

molt In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer ...

, the larvae grow hooked hairs which allow them to be carried in groups. When ''Lasius niger'' larvae reach the last molt they are generally too big to be carried as part of a group and so are carried individually. Once the larva grows big enough it spins a cocoon around itself. To aid this process a queen (or workers) may bury the larva so that it can spin its cocoon undisturbed, and begin a process of

metamorphosis Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...

. Once the process is complete the ''Lasius niger'' worker emerges from the cocoon. At this stage, the callow worker is completely white but will darken over the course of an hour until it has turned black.

Colony established

The first worker ants that emerge are very small compared to later generations. At this point the workers immediately begin to expand the nest and care for the queen and brood; they eventually remove the seal from the entrance to the nest and begin to forage above ground. This is a critical time for the colony as they need to gather food quickly to support future growth and particularly to feed the starved queen, who would have lost around 50% of her body weight. From this point on the queen's egg laying output will increase significantly, becoming the queen's sole function. The later generations of worker ants will be bigger, stronger and more aggressive because there is more nutrition for them at the larval stage. The initial brood being fed only by the scarce resources available to a queen will be much smaller than brood supported by a team of foraging and nursing workers. Provided workers are able to find food, at this stage the colony will see an exponential rise in population. After several years, once the colony is well established, the queen will lay eggs that will become queens and males. Black ants often make large nests with extensive tunnel connections.

Quarantine behavior

When building their colony, the ants structure it so as to inhibit the transmission of different contagions. Different communities within the colony are segregated by a limited number of connective nodes, allowing for greater protection of vulnerable hive members, such as larvae and pupae, and the queen. Additionally, individual infected ants have been observed as spending more time

foraging Foraging is searching for wild food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce. Foraging theory is a branch of behavioral ecology that studies the foraging behavi ...

outside of the hive, venturing farther than other ants, and limiting their interactions once within the hive again.

Long-lived queens

Although worker ants live for a couple of months, queens typically survive for almost 15 years but there have been instances of queens living up to 29 years, the longest recorded lifespan for any eusocial insect. Understanding the basis for the greater

longevity The word " longevity" is sometimes used as a synonym for " life expectancy" in demography. However, the term ''longevity'' is sometimes meant to refer only to especially long-lived members of a population, whereas ''life expectancy'' is always ...

of queens has a bearing on the general unsolved problem in biology of the causes of

aging Ageing ( BE) or aging ( AE) is the process of becoming older. The term refers mainly to humans, many other animals, and fungi, whereas for example, bacteria, perennial plants and some simple animals are potentially biologically immortal. In ...

. In the study of long-lived queen ants it was found that queens have a higher expression than genetically identical workers of

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

s involved in processing damaged

macromolecule A macromolecule is a very large molecule important to biophysical processes, such as a protein or nucleic acid. It is composed of thousands of covalently bonded atoms. Many macromolecules are polymers of smaller molecules called monomers. The ...

s. Genes with higher expression included those that are necessary for repair of

DNA damage DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as radiation can cause DNA d ...

(see

DNA damage theory of aging The DNA damage theory of aging proposes that aging is a consequence of unrepaired accumulation of naturally occurring DNA damage. Damage in this context is a DNA alteration that has an abnormal structure. Although both mitochondrial and nuclear D ...

) and genes involved in

proteasome Proteasomes are protein complexes which degrade unneeded or damaged proteins by proteolysis, a chemical reaction that breaks peptide bonds. Enzymes that help such reactions are called proteases. Proteasomes are part of a major mechanism by whi ...

-mediated,

ubiquitin Ubiquitin is a small (8.6 kDa) regulatory protein found in most tissues of eukaryotic organisms, i.e., it is found ''ubiquitously''. It was discovered in 1975 by Gideon Goldstein and further characterized throughout the late 1970s and 1980s. Fo ...

-dependent, protein catabolic processes.

Mutualisms

''Lasius niger'' removes predators such as ladybirds from the vicinity of

black bean aphid The black bean aphid (''Aphis fabae'') is a small black insect in the genus ''Aphis'', with a broad, soft body, a member of the order Hemiptera. Other common names include blackfly, bean aphid, and beet leaf aphid. In the warmer months of the yea ...

thus keeping their "milch cows" safe. On a test plot of field beans (''

Vicia faba ''Vicia faba'', commonly known as the broad bean, fava bean, or faba bean, is a species of vetch, a flowering plant in the pea and bean family Fabaceae. It is widely cultivated as a crop for human consumption, and also as a cover crop. Varieti ...

''), plants without black bean aphids yielded an average of 56 seeds per plant, those with aphids and no ants yielded 17 seeds, and those with both ants and aphids averaged eight seeds per plant. ''Vicia faba'' also produces

extrafloral nectaries Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualis ...

that ''Lasius niger'' can feed from directly. The ''Plebejus argus'' butterfly lays eggs near nests of ''L. niger'', forming a mutualistic relationship. This mutualistic relationship benefits the adult butterfly by reducing the need for parental investment. Once the eggs hatch, the ants chaperone the larvae, averting the attacks of predatory organisms like

wasp A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder ...

s and

spider Spiders (order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...

s as well as parasites. In return, the ants receive a saccharine secretion fortified with

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha ...

s from an eversible gland on the larvae's back. As first instar larvae prepare to pupate, the ants carry the larvae into their nests. Once the larvae become pupae, the ants continue to provide protection against predation and parasitism. The butterfly leaves the nest when it emerges in June.

References

External links

Antkeepers has an article on Lasius nigerThe Kurt Kuene Antpage: Kurt Kuene shows how he keeps Lasius niger. With many pictures
{{Authority control Lasius Hymenoptera of Asia Hymenoptera of Europe Hymenoptera of North America Ants described in 1758 Taxa named by Carl Linnaeus