Mycocepurus smithii
Encyclopedia
Mycocepurus smithii is an attine
fungus-growing ant
from Latin America
whose species consists exclusively of females which reproduce asexually
. The queen
reproduces by parthenogenesis
and all ants in a colony
are female clone
s of the queen. The ants cultivate a garden of fungus
inside their colony
grown with pieces of dead vegetables and other insects. It is this capacity for farming which initially prompted research into the species as a basal
genus member would provide insight into the natural history of the fungal-cultivating ant tribe, Attini.
Ants of the genus Mycocepurus are distinctly recognizable for the crown-like cluster of horns on their promesonotum, the fused mesonotum and pronotum on the front of their alitrunk or midsection. M. smithii has sharp, protruding propodeal (posterior of the alitrunk) spines unlike M. obsoletus whose propodeal spines are blunt. Workers also do not have developed promesonotal spines in the center of their crown.
prior to colony excavation either near the site or just inside. They then excavate a tunnel to a depth of roughly 10 cm (4 in) and create a primary chamber. The dealate
queen then carries the wings into the primary chamber and inserts them into the chamber ceiling where the surface of the wings is used as a platform for growing an incipient fungal garden. The female fore wings of all three Attini basal
genera (Mycocepurus
, Apterostigma, and Myrmicocrypta) have a crescent-shaped spot lacking any veins or pigmentation, though the spot's functionality is unknown.
, Costa Rica
, and Trinidad
have a single entrance, though the close proximity to other nests in high colony-density areas may give the illusion of multiple entrances. M. Smithii nests consist of a mound excavated around an entrance roughly 1.2 mm in diameter. This leads to a vertical tunnel opening into the garden chamber at a depth of approximately 12.5 mm. M. Smithii maintain narrow tunnels (diameter of 1.3 mm) which do not allow two ants to pass each other in the tunnel (head size is approximately 0.7 mm for workers and 0.9 mm for queens). The tunnels also have a number of slightly larger sections (approximately 3.6 mm diameter) which would allow passing while also facilitating information exchange. Narrow tunnels are presumably easier (energetically cheaper) to construct and may also aide in leveling the humidity or temperature of the colony or preventing predatory intrusions.
in the United States, Anna Himler. The researchers initially were interested in the ants' capability for cultivating fungus
. The researchers used DNA profiling to confirm that each member of the colony was genetically identical to the queen. They also discovered through a process of dissection that the mussel organ, a female docking apparatus within the vagina used to hook the mate's genitalia, had degenerated in members of this species. A total of six separate tests were carried out, with the researchers unable to locate any male members of the species. The team's findings were then published in the journal Proceedings of the Royal Society B
.
Fungus-growing ants
The fungus-growing ants comprises all the known fungus-growing ant species in the world participating in ant-fungus mutualism. Leafcutter ants, including Atta and Acromyrmex, make up 2 of the genera.-See also:...
fungus-growing 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...
from Latin America
Latin America
Latin America is a region of the Americas where Romance languages – particularly Spanish and Portuguese, and variably French – are primarily spoken. Latin America has an area of approximately 21,069,500 km² , almost 3.9% of the Earth's surface or 14.1% of its land surface area...
whose species consists exclusively of females which reproduce asexually
Asexual reproduction
Asexual reproduction is a mode of reproduction by which offspring arise from a single parent, and inherit the genes of that parent only, it is reproduction which does not involve meiosis, ploidy reduction, or fertilization. A more stringent definition is agamogenesis which is reproduction without...
. The queen
Queen 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...
reproduces by parthenogenesis
Parthenogenesis
Parthenogenesis is a form of asexual reproduction found in females, where growth and development of embryos occur without fertilization by a male...
and all ants in a colony
Ant colony
An ant colony is an underground lair where ants live, eat and mate. Colonies consist of a series of underground chambers, connected to each other and the surface of the earth by small tunnels. There are rooms for nurseries, food storage, and mating...
are female clone
Cloning
Cloning in biology is the process of producing similar populations of genetically identical individuals that occurs in nature when organisms such as bacteria, insects or plants reproduce asexually. Cloning in biotechnology refers to processes used to create copies of DNA fragments , cells , or...
s of the queen. The ants cultivate a garden of fungus
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
inside their colony
Ant colony
An ant colony is an underground lair where ants live, eat and mate. Colonies consist of a series of underground chambers, connected to each other and the surface of the earth by small tunnels. There are rooms for nurseries, food storage, and mating...
grown with pieces of dead vegetables and other insects. It is this capacity for farming which initially prompted research into the species as a basal
Basal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
genus member would provide insight into the natural history of the fungal-cultivating ant tribe, Attini.
Description
Fungal cultivation
Foundress queens shed their wingsNuptial flight
Nuptial flight is an important phase in the reproduction of most ant, termite and some bee species. During the flight, virgin queens mate with males and then land to start a new colony, or, in the case of honey bees, continue the planned succession of an existing hived colony.- Before the flight :A...
prior to colony excavation either near the site or just inside. They then excavate a tunnel to a depth of roughly 10 cm (4 in) and create a primary chamber. The dealate
Alate
An alate is a winged reproductive of a social insect . Alate females are typically those destined to become queens , whereas alate males are occasionally referred to as "drones"...
queen then carries the wings into the primary chamber and inserts them into the chamber ceiling where the surface of the wings is used as a platform for growing an incipient fungal garden. The female fore wings of all three Attini basal
Basal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
genera (Mycocepurus
Mycocepurus
Mycocepurus is a genus of ants. One of its species, Mycocepurus smithii, which lives in South America, reproduces by cloning – all ants in a colony are clones of the queen.Contains the following species:...
, Apterostigma, and Myrmicocrypta) have a crescent-shaped spot lacking any veins or pigmentation, though the spot's functionality is unknown.
Nest architecture
M. Smithii nests in Puerto RicoPuerto Rico
Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...
, Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....
, and Trinidad
Trinidad
Trinidad is the larger and more populous of the two major islands and numerous landforms which make up the island nation of Trinidad and Tobago. It is the southernmost island in the Caribbean and lies just off the northeastern coast of Venezuela. With an area of it is also the fifth largest in...
have a single entrance, though the close proximity to other nests in high colony-density areas may give the illusion of multiple entrances. M. Smithii nests consist of a mound excavated around an entrance roughly 1.2 mm in diameter. This leads to a vertical tunnel opening into the garden chamber at a depth of approximately 12.5 mm. M. Smithii maintain narrow tunnels (diameter of 1.3 mm) which do not allow two ants to pass each other in the tunnel (head size is approximately 0.7 mm for workers and 0.9 mm for queens). The tunnels also have a number of slightly larger sections (approximately 3.6 mm diameter) which would allow passing while also facilitating information exchange. Narrow tunnels are presumably easier (energetically cheaper) to construct and may also aide in leveling the humidity or temperature of the colony or preventing predatory intrusions.
Himler research
The research team was led by a graduate student at the University of Texas at AustinUniversity of Texas at Austin
The University of Texas at Austin is a state research university located in Austin, Texas, USA, and is the flagship institution of the The University of Texas System. Founded in 1883, its campus is located approximately from the Texas State Capitol in Austin...
in the United States, Anna Himler. The researchers initially were interested in the ants' capability for cultivating fungus
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...
. The researchers used DNA profiling to confirm that each member of the colony was genetically identical to the queen. They also discovered through a process of dissection that the mussel organ, a female docking apparatus within the vagina used to hook the mate's genitalia, had degenerated in members of this species. A total of six separate tests were carried out, with the researchers unable to locate any male members of the species. The team's findings were then published in the journal Proceedings of the Royal Society B
Proceedings of the Royal Society
Proceedings of the Royal Society is the parent title of two scientific journals published by the Royal Society, whereas its initial journal, Philosophical Transactions, is now devoted to special thematic issues...
.
Further reading
- Anna Grace Himler, Ph.D. Dissertation: Evolutionary Ecology and Natural History of Fungus-Growing Ants: Host-Switching, Divergence, and Asexuality. Chapter 3. No sex in fungus-farming ants or their crops, 2007.