Euprenolepis procera
Encyclopedia
Euprenolepis procera is a species of ant
found in the rainforest
s of South East Asia. It was first described
by Carlo Emery
, an Italian entomologist in 1900. In 2008, Witte & Maschwitz discovered that E. procera specialises in harvesting mushroom
s in the rainforest for food, representing a new, previously unreported feeding strategy in ants.
and Indonesia
. In Malaysia, where they have been studied, individual colonies were recorded to occur at a density of one nest per approximately 150 m2, but Witte & Maschwitz stated this may be an underestimate as they may not have discovered some colonies.
in 1900 by Carlo Emery
, under the name Prenolepis procera; Emery based his description on material collected by the Italian anthropologist Elio Modigliani
in his travels in Malesia
. Emery assigned the species to the subgenus Euprenolepis in 1905, and moved that subgenus to the genus Paratrechina
in 1925. In 1995, Bolton raised the subgenus to the rank of genus
, giving the species its current name.
In 1913, Auguste-Henri Forel described a new species, Camponotus (Myrmosphincta) antespectans, which was also moved to Euprenolepis by Emery. This is now considered a synonym
of E. procera.
, consisting of a minor (body length = 3.5 millimetre) and major caste (body length = 5 millimetre); the major caste is relatively rare compared to the minor caste. The workers' heads are heart-shaped, broader than they are long and a "dark-reddish brown" colour. The antennae
of both worker castes are made up of twelve segments and are a lighter colour than their heads, their mandibles have five teeth. The major workers superficially resemble species of Pseudolasius.
s and male
s have larger eye
s than the workers, and also have three pronounced simple eyes as well. The queens are covered in a dense layer of hairs. The antennae of the males are made of thirteen segments, unlike twelve in workers, and their mandibles have only one well-developed tooth. The queens are a similar colour to the workers, but have mottled areas that are a lighter colour than the rest of the body.
regularly, staying in each location for between one and nine days; these migrations are thought to be necessary as the colony quickly depletes available food near its nest. Similar adaptations to unpredictable food resources are only seen in two other types of ant; army ant
s which migrate into new foraging areas and Dolichoderus
transport their trophobiont mealybug
s to parts of plants that are growing.
have co-evolved with fungi, forming a mutualism
that benefits both the fungus and the ants. Unlike similar ants found in the New World
, E. procera does not cultivate fungi in its nest, but instead harvests the sporocarp
of fungi (mushrooms) from the rainforest in which it lives as its primary source of food. E. procera is the only species of ant known to have such a feeding habit. When it was first reported in 2008, Bert Hölldobler
, an expert on ants, called the discovery "sensational" and said "nothing like that was known before". They have been observed to eat over 30 species of mushroom, but they also ignore 50 species present in their habitat; of those that they do eat, the mushrooms often occurred near the roots of trees, indicating that mycorrhizal fungi form part of their diet. During field observations only two occurrences of them feeding on animals (a grasshopper
and a snail
) were recorded, compared to 266 mushrooms which were consumed. In a laboratory study, colonies thrived for over thirteen weeks, being fed on a diet consisting only of Pleurotus
and Agaricus
mushrooms. Combined, these observations led Witte & Maschwitz to conclude that the natural diet consists almost entirely of mushrooms. Feeding experiments demonstrated that they are able to live off a diet of honey or insects as well.
Once they locate mushrooms which they consider edible in the wild, they harvest them efficiently, removing over 70% of the mushroom within four hours. In a laboratory study, they almost completetly harvested a Pleurotus mushroom that weighed 40 grams (1.4 oz) within three hours. Once they have harvested the mushrooms, they transport pieces of them back to their nest and arrange them into piles 1–4 cm (0.393700787401575–1.6 ) in diameter. Over time these piles turn from white to black, losing mass as workers continuously chew and feed on the fungi and in turn feed the ant larvae
. The pulp has a distinctive sweet-sour odour, which Witte & Maschwitz suggested may be due to fermentation
occurring. This food processing continues for around a week, depending on the size of the original pile of pieces. If the fungal material is kept away from the ants it quickly spoils, becoming infested by bacteria and smelling unpleasant, but when processed by the ants no spoiling has been observed. The exact mechanisms of the processing of fungi are under investigation.
They are thought to have evolved this feeding habit because few other animals eat mushrooms and therefore there is little competition
for the food resource. When mushrooms were placed near nests of E. procera they were by far the main consumer of the mushrooms with other animals barely feeding on them.
is currently unknown. Witte & Maschwitz suggested that they may have similar effects on the ecosystem to ants that harvest seeds of plants, by changing the relative abundance of different fungal species.
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...
found in the rainforest
Rainforest
Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...
s of South East Asia. It was first described
Species description
A species description or type description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species which have been described previously, or are...
by Carlo Emery
Carlo Emery
Carlo Emery was an Italian entomologist.Born in Naples, Carlo Emery was professor of Zoology at the University of Bologna. He later worked in Geneva...
, an Italian entomologist in 1900. In 2008, Witte & Maschwitz discovered that E. procera specialises in harvesting mushroom
Mushroom
A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. The standard for the name "mushroom" is the cultivated white button mushroom, Agaricus bisporus; hence the word "mushroom" is most often applied to those fungi that...
s in the rainforest for food, representing a new, previously unreported feeding strategy in ants.
Distribution
E. procera is endemic to South East Asia, being found in the rainforests of Malaysia, ThailandThailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
and Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
. In Malaysia, where they have been studied, individual colonies were recorded to occur at a density of one nest per approximately 150 m2, but Witte & Maschwitz stated this may be an underestimate as they may not have discovered some colonies.
Taxonomy
E. procera was first describedAlpha taxonomy
Alpha taxonomy is the discipline concerned with finding, describing and naming species of living or fossil organisms. This field is supported by institutions holding collections of these organisms, with relevant data, carefully curated: such institutes include natural history museums, herbaria and...
in 1900 by Carlo Emery
Carlo Emery
Carlo Emery was an Italian entomologist.Born in Naples, Carlo Emery was professor of Zoology at the University of Bologna. He later worked in Geneva...
, under the name Prenolepis procera; Emery based his description on material collected by the Italian anthropologist Elio Modigliani
Elio Modigliani
Elio Modigliani was an Italian anthropologist, zoologist, and plant collector. Between 1886 and 1894, he explored Sumatra and a number of islands off its western coast. Modigliani visited Enggano Island between April 25 and July 13, 1891...
in his travels in Malesia
Malesia
Malesia is a biogeographical region straddling the boundaries of the Indomalaya ecozone and Australasia ecozone, and also a phytogeographical floristic region in the Paleotropical Kingdom.-Floristic province:...
. Emery assigned the species to the subgenus Euprenolepis in 1905, and moved that subgenus to the genus Paratrechina
Paratrechina
Paratrechina is an ant genus from the subfamily Formicinae .There are over 150 described species and subspecies, some of which occur on every continent...
in 1925. In 1995, Bolton raised the subgenus to the rank of genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
, giving the species its current name.
In 1913, Auguste-Henri Forel described a new species, Camponotus (Myrmosphincta) antespectans, which was also moved to Euprenolepis by Emery. This is now considered a synonym
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
of E. procera.
Workers
The workers are polymorphicPolymorphism (biology)
Polymorphism in biology occurs when two or more clearly different phenotypes exist in the same population of a species — in other words, the occurrence of more than one form or morph...
, consisting of a minor (body length = 3.5 millimetre) and major caste (body length = 5 millimetre); the major caste is relatively rare compared to the minor caste. The workers' heads are heart-shaped, broader than they are long and a "dark-reddish brown" colour. 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....
of both worker castes are made up of twelve segments and are a lighter colour than their heads, their mandibles have five teeth. The major workers superficially resemble species of Pseudolasius.
Reproductive castes
The queenQueen ant
A queen ant is an adult, reproducing female ant in an ant colony; generally she will be the mother of all the other ants in that colony. Some female ants do not need to mate to produce offspring, reproducing through asexual parthenogenesis or cloning and all of those offspring will be female.Ant...
s and male
Male
Male refers to the biological sex of an organism, or part of an organism, which produces small mobile gametes, called spermatozoa. Each spermatozoon can fuse with a larger female gamete or ovum, in the process of fertilization...
s have larger eye
Eye
Eyes are organs that detect light and convert it into electro-chemical impulses in neurons. The simplest photoreceptors in conscious vision connect light to movement...
s than the workers, and also have three pronounced simple eyes as well. The queens are covered in a dense layer of hairs. The antennae of the males are made of thirteen segments, unlike twelve in workers, and their mandibles have only one well-developed tooth. The queens are a similar colour to the workers, but have mottled areas that are a lighter colour than the rest of the body.
Behaviour
E. procera is nocturnal, only foraging for food at night, venturing up to 40 metres (131.2 ft) from the nest, but on average around 12 metre. It lives in colonies of between 500 and 50,000 individuals, forming nests inside preformed cavities, rather than constructing nests themselves. They migrateAnimal migration
Animal migration is the relatively long-distance movement of individuals, usually on a seasonal basis. It is a ubiquitous phenomenon, found in all major animal groups, including birds, mammals, fish, reptiles, amphibians, insects, and crustaceans. The trigger for the migration may be local...
regularly, staying in each location for between one and nine days; these migrations are thought to be necessary as the colony quickly depletes available food near its nest. Similar adaptations to unpredictable food resources are only seen in two other types of ant; army ant
Army ant
The name army ant is applied to over 200 ant species, in different lineages, due to their aggressive predatory foraging groups, known as "raids", in which huge numbers of ants forage simultaneously over a certain area, attacking prey en masse.Another shared feature is that, unlike most ant...
s which migrate into new foraging areas and Dolichoderus
Dolichoderus
Dolichoderus is a large genus of ants found worldwide.-Taxonomy:The ants of the neotropical genus Monacio were revised in 1959 by Kempf. However, Brown in 1973 and G. C. Wheeler and J. Wheeler in 1973 and 1976 considered both Monacis and Hypoclinea to be junior synonyms of...
transport their trophobiont mealybug
Mealybug
Mealybugs are insects in the family Pseudococcidae, unarmored scale insects found in moist, warm climates. They are considered pests as they feed on plant juices of greenhouse plants, house plants and subtropical trees and also acts as a vector for several plant diseases.-Distribution:Mealybugs...
s to parts of plants that are growing.
Feeding
Over 200 species of ants are known to eat fungi as a major part of their diet, but these ants in the Attini tribeTribe (biology)
In biology, a tribe is a taxonomic rank between family and genus. It is sometimes subdivided into subtribes.Some examples include the tribes: Canini, Acalypheae, Hominini, Bombini, and Antidesmeae.-See also:* Biological classification* Rank...
have co-evolved with fungi, forming a mutualism
Ant-fungus mutualism
Ant-fungus mutualism is a symbiosis seen in certain ant and fungal species, where ants actively cultivate fungus much like humans farm crops as a food source. In some species, the ants and fungi are dependent on each other for survival. The leafcutter ant is a well known example of this symbiosis...
that benefits both the fungus and the ants. Unlike similar ants found in the New World
New World
The New World is one of the names used for the Western Hemisphere, specifically America and sometimes Oceania . The term originated in the late 15th century, when America had been recently discovered by European explorers, expanding the geographical horizon of the people of the European middle...
, E. procera does not cultivate fungi in its nest, but instead harvests the sporocarp
Sporocarp
Sporocarp can refer to any of several structures whose primary function is the production and release of spores.* Sporocarp , a multicellular structure on which spore-producing structures are borne....
of fungi (mushrooms) from the rainforest in which it lives as its primary source of food. E. procera is the only species of ant known to have such a feeding habit. When it was first reported in 2008, Bert Hölldobler
Bert Hölldobler
Bert Hölldobler is a German behavioral biologist and Sociobiologist whose primary study subjects are social insects and in particular ants. He is a co-winner of the Pulitzer Prize for his work on The Ants with Edward O. Wilson...
, an expert on ants, called the discovery "sensational" and said "nothing like that was known before". They have been observed to eat over 30 species of mushroom, but they also ignore 50 species present in their habitat; of those that they do eat, the mushrooms often occurred near the roots of trees, indicating that mycorrhizal fungi form part of their diet. During field observations only two occurrences of them feeding on animals (a grasshopper
Grasshopper
The grasshopper is an insect of the suborder Caelifera in the order Orthoptera. To distinguish it from bush crickets or katydids, it is sometimes referred to as the short-horned grasshopper...
and a snail
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
) were recorded, compared to 266 mushrooms which were consumed. In a laboratory study, colonies thrived for over thirteen weeks, being fed on a diet consisting only of Pleurotus
Pleurotus
Pleurotus is a genus of gilled mushrooms which includes one of the most widely eaten mushrooms, P. ostreatus. Species of Pleurotus may be called oyster, abalone, or tree mushrooms, and are some of the most commonly cultivated edible mushrooms in the world...
and Agaricus
Agaricus
Agaricus is a large and important genus of mushrooms containing both edible and poisonous species, with possibly over 300 members worldwide...
mushrooms. Combined, these observations led Witte & Maschwitz to conclude that the natural diet consists almost entirely of mushrooms. Feeding experiments demonstrated that they are able to live off a diet of honey or insects as well.
Once they locate mushrooms which they consider edible in the wild, they harvest them efficiently, removing over 70% of the mushroom within four hours. In a laboratory study, they almost completetly harvested a Pleurotus mushroom that weighed 40 grams (1.4 oz) within three hours. Once they have harvested the mushrooms, they transport pieces of them back to their nest and arrange them into piles 1–4 cm (0.393700787401575–1.6 ) in diameter. Over time these piles turn from white to black, losing mass as workers continuously chew and feed on the fungi and in turn feed the ant larvae
Larvae
In Roman mythology, lemures were shades or spirits of the restless or malignant dead, and are probably cognate with an extended sense of larvae as disturbing or frightening...
. The pulp has a distinctive sweet-sour odour, which Witte & Maschwitz suggested may be due to fermentation
Fermentation (biochemistry)
Fermentation is the process of extracting energy from the oxidation of organic compounds, such as carbohydrates, using an endogenous electron acceptor, which is usually an organic compound. In contrast, respiration is where electrons are donated to an exogenous electron acceptor, such as oxygen,...
occurring. This food processing continues for around a week, depending on the size of the original pile of pieces. If the fungal material is kept away from the ants it quickly spoils, becoming infested by bacteria and smelling unpleasant, but when processed by the ants no spoiling has been observed. The exact mechanisms of the processing of fungi are under investigation.
They are thought to have evolved this feeding habit because few other animals eat mushrooms and therefore there is little competition
Competition (biology)
Competition is an interaction between organisms or species, in which the fitness of one is lowered by the presence of another. Limited supply of at least one resource used by both is required. Competition both within and between species is an important topic in ecology, especially community ecology...
for the food resource. When mushrooms were placed near nests of E. procera they were by far the main consumer of the mushrooms with other animals barely feeding on them.
Ecological significance
The effects that harvesting of mushrooms by E. procera has on the ecosystemEcosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
is currently unknown. Witte & Maschwitz suggested that they may have similar effects on the ecosystem to ants that harvest seeds of plants, by changing the relative abundance of different fungal species.