Acromyrmex coronatus
Encyclopedia
Acromyrmex coronatus is a species
of leaf-cutter ant, a New World ant of the subfamily Myrmicinae
of the genus
Acromyrmex. This species is from one of the two genera of advanced attines
(fungus-growing ants) within the tribe Attini. It is found in the wild naturally from Guatemala
to Brazil
and Ecuador
.
within the tribe Attini.
Acromyrmex can be identified from the closely related Atta genus
of leafcutter ants since they have 4 pairs of spines and a rough exoskeleton on the upper surface of the thorax
.
A mature Acromyrmex coronatus colony contains mostly sterile female workers. They are divided into castes
, based mostly on size, that perform different functions. Acromyrmex exhibit a high degree of biological polymorphism
, four castes being present in established colonies - minims (or "garden ants"), minors, mediae and majors. Majors are also known as soldiers or dinergates. Each caste has a specific function within the colony. Acromyrmex ants are less polymorphic than the other genera of leafcutter ants Atta, meaning that there is comparatively less differential in size from the smallest to largest types of Acromymex. The high degree of polymorphism in this genus is also suggestive of its high degree of advancement.
Like Atta, Acromyrmex subsists mostly on a particular species of fungus (genus Leucocoprinus
) which it cultivates on a medium of masticated leaf tissue. This is the sole food of the queen
and other colony members that remain in the nest. The media workers also gain subsistence from plant sap they ingest whilst physically cutting out sections of leaf from a variety of plants.
Before leaving their parent colonies, winged females take a small section of fungus into their bucchal pouches and it is with this that the subsequently wingless queens 'seed' the fungus gardens of incipient colonies, cutting and collecting the first few sections of leaf themselves.
Acromyrmex has evolved to change foodplant constantly, preventing a colony from completely stripping off leaves and thereby killing trees, thus avoiding negative biological feedback on account of their sheer numbers. However, this does not diminish the huge quantities of foliage they harvest.
Acromyrmex coronatus can be identified by the presence of median pronotal spines being usually present and distinct, occasionally reduced or absent; the head tapering behind eyes; and head width of less than or equal to 1.7mm.
Acromyrmex coronatus is a montane species found in cloud forest
habitats and not in lowland
s. It is tolerant of cold, wet conditions and colonies can be found in small clearings and gaps in dense cloud forest. For example on the north side of Volcan Barva it has been found at 1100m elevation but not at 500m or 2000m. On the Central Valley side it has been collected at 1600m elevation at Zurqui. In the Monteverde area it occurs in the community area, up to the highest ridges at 1700m, and down to 800m in the Penas Blancas Valley.
In Monteverde, it is the main pest in gardens and will come into houses at night to cut bread, cabbage, or fruit that has been left out. The nests are often in or under a piece of dead wood, and often with a superstructure of loose dead leaf fragments. They do not excavate soil very extensively if at all. They may be arboreal at times, nesting in a low branch junctions of epiphyte-laden trees.
A. coronatus foraging is continuous at night, but diurnal foraging only occurs when there had been recent rain. Following a heavy rain, diurnal foraging will commence followed by a gradual cessation over a period of a day or two. Periodic rains during the dry season initiate a short bout of diurnal foraging, but when the rains became more continuous diurnal foraging becomes continuous. Thus the lack of diurnal foraging during the dry season is a short-term response to immediate environmental conditions and not a long-term change in colony foraging behavior.
Nuptial flights are common in Monteverde and the distinctively-patterned dealate queens are often seen on the roads. Dealate queens have been observed out cutting leaves, suggesting that queens need to forage themselves to establish a colony.
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 leaf-cutter ant, a New World ant of the subfamily Myrmicinae
Myrmicinae
Myrmicinae is a subfamily of ants. There are about 140 genera within the group, with the family being cosmopolitan. The pupae lack cocoons. Some species retain a functional sting. The petioles of Myrmicinae consist of two nodes...
of the 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...
Acromyrmex. This species is from one of the two genera of advanced attines
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 ants) within the tribe Attini. It is found in the wild naturally from Guatemala
Guatemala
Guatemala 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...
to Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
and Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
.
Overview
Commonly known as "leaf-cutter ants" they are a species of ant from one of the two genera of advanced attinesFungus-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:...
within the tribe Attini.
Acromyrmex can be identified from the closely related Atta 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...
of leafcutter ants since they have 4 pairs of spines and a rough exoskeleton on the upper surface of the thorax
Thorax (insect anatomy)
The thorax is the mid section of the insect body. It holds the head, legs, wings and abdomen. It is also called mesosoma in other arthropods....
.
A mature Acromyrmex coronatus colony contains mostly sterile female workers. They are divided into castes
Eusociality
Eusociality is a term used for the highest level of social organization in a hierarchical classification....
, based mostly on size, that perform different functions. Acromyrmex exhibit a high degree of biological polymorphism
Polymorphism (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...
, four castes being present in established colonies - minims (or "garden ants"), minors, mediae and majors. Majors are also known as soldiers or dinergates. Each caste has a specific function within the colony. Acromyrmex ants are less polymorphic than the other genera of leafcutter ants Atta, meaning that there is comparatively less differential in size from the smallest to largest types of Acromymex. The high degree of polymorphism in this genus is also suggestive of its high degree of advancement.
Like Atta, Acromyrmex subsists mostly on a particular species of fungus (genus Leucocoprinus
Leucocoprinus
Leucocoprinus is a genus of fungi in the family Agaricaceae. Its best known member is the yellow pot-plant mushroom , found worldwide. The type species is Leucocoprinus cepistipes...
) which it cultivates on a medium of masticated leaf tissue. This is the sole food of the queen
Eusociality
Eusociality is a term used for the highest level of social organization in a hierarchical classification....
and other colony members that remain in the nest. The media workers also gain subsistence from plant sap they ingest whilst physically cutting out sections of leaf from a variety of plants.
Before leaving their parent colonies, winged females take a small section of fungus into their bucchal pouches and it is with this that the subsequently wingless queens 'seed' the fungus gardens of incipient colonies, cutting and collecting the first few sections of leaf themselves.
Acromyrmex has evolved to change foodplant constantly, preventing a colony from completely stripping off leaves and thereby killing trees, thus avoiding negative biological feedback on account of their sheer numbers. However, this does not diminish the huge quantities of foliage they harvest.
Acromyrmex coronatus can be identified by the presence of median pronotal spines being usually present and distinct, occasionally reduced or absent; the head tapering behind eyes; and head width of less than or equal to 1.7mm.
Acromyrmex coronatus is a montane species found in cloud forest
Cloud forest
A cloud forest, also called a fog forest, is a generally tropical or subtropical evergreen montane moist forest characterized by a persistent, frequent or seasonal low-level cloud cover, usually at the canopy level. Cloud forests often exhibit an abundance of mosses covering the ground and...
habitats and not in lowland
Lowland
In physical geography, a lowland is any broad expanse of land with a general low level. The term is thus applied to the landward portion of the upward slope from oceanic depths to continental highlands, to a region of depression in the interior of a mountainous region, to a plain of denudation, or...
s. It is tolerant of cold, wet conditions and colonies can be found in small clearings and gaps in dense cloud forest. For example on the north side of Volcan Barva it has been found at 1100m elevation but not at 500m or 2000m. On the Central Valley side it has been collected at 1600m elevation at Zurqui. In the Monteverde area it occurs in the community area, up to the highest ridges at 1700m, and down to 800m in the Penas Blancas Valley.
In Monteverde, it is the main pest in gardens and will come into houses at night to cut bread, cabbage, or fruit that has been left out. The nests are often in or under a piece of dead wood, and often with a superstructure of loose dead leaf fragments. They do not excavate soil very extensively if at all. They may be arboreal at times, nesting in a low branch junctions of epiphyte-laden trees.
A. coronatus foraging is continuous at night, but diurnal foraging only occurs when there had been recent rain. Following a heavy rain, diurnal foraging will commence followed by a gradual cessation over a period of a day or two. Periodic rains during the dry season initiate a short bout of diurnal foraging, but when the rains became more continuous diurnal foraging becomes continuous. Thus the lack of diurnal foraging during the dry season is a short-term response to immediate environmental conditions and not a long-term change in colony foraging behavior.
Nuptial flights are common in Monteverde and the distinctively-patterned dealate queens are often seen on the roads. Dealate queens have been observed out cutting leaves, suggesting that queens need to forage themselves to establish a colony.
Subspecies
- Acromyrmex coronatus andicola
- Acromyrmex coronatus globoculis
- Acromyrmex coronatus importunus
- Acromyrmex coronatus panamensis
- Acromyrmex coronatus rectispinus
Synonyms
- Acromyrmex flavescens GoncalvesGonçalves-People:* Adílio de Oliveira Gonçalves, Brazilian footballer* Ailton Gonçalves da Silva, Brazilian footballer* André Gonçalves, 15th/16th-century Portuguese explorer of Brasil* Antão Gonçalves, 15th century Portuguese explorer...
, 1961 - Acromyrmex medianus GoncalvesGonçalves-People:* Adílio de Oliveira Gonçalves, Brazilian footballer* Ailton Gonçalves da Silva, Brazilian footballer* André Gonçalves, 15th/16th-century Portuguese explorer of Brasil* Antão Gonçalves, 15th century Portuguese explorer...
, 1961 - Acromyrmex meinerti GonçalvesGonçalves-People:* Adílio de Oliveira Gonçalves, Brazilian footballer* Ailton Gonçalves da Silva, Brazilian footballer* André Gonçalves, 15th/16th-century Portuguese explorer of Brasil* Antão Gonçalves, 15th century Portuguese explorer...
, 1961 - Acromyrmex modesta GoncalvesGonçalves-People:* Adílio de Oliveira Gonçalves, Brazilian footballer* Ailton Gonçalves da Silva, Brazilian footballer* André Gonçalves, 15th/16th-century Portuguese explorer of Brasil* Antão Gonçalves, 15th century Portuguese explorer...
, 1961 - Acromyrmex moelleri GoncalvesGonçalves-People:* Adílio de Oliveira Gonçalves, Brazilian footballer* Ailton Gonçalves da Silva, Brazilian footballer* André Gonçalves, 15th/16th-century Portuguese explorer of Brasil* Antão Gonçalves, 15th century Portuguese explorer...
, 1961 - Acromyrmex obscurior GoncalvesGonçalves-People:* Adílio de Oliveira Gonçalves, Brazilian footballer* Ailton Gonçalves da Silva, Brazilian footballer* André Gonçalves, 15th/16th-century Portuguese explorer of Brasil* Antão Gonçalves, 15th century Portuguese explorer...
, 1961 - Acromyrmex ochraceolus GoncalvesGonçalves-People:* Adílio de Oliveira Gonçalves, Brazilian footballer* Ailton Gonçalves da Silva, Brazilian footballer* André Gonçalves, 15th/16th-century Portuguese explorer of Brasil* Antão Gonçalves, 15th century Portuguese explorer...
, 1961 - Acromyrmex ornatus GoncalvesGonçalves-People:* Adílio de Oliveira Gonçalves, Brazilian footballer* Ailton Gonçalves da Silva, Brazilian footballer* André Gonçalves, 15th/16th-century Portuguese explorer of Brasil* Antão Gonçalves, 15th century Portuguese explorer...
, 1961 - Formica coronata FabriciusJohan Christian FabriciusJohan Christian Fabricius was a Danish zoologist, specialising in "Insecta", which at that time included all arthropods: insects, arachnids, crustaceans and others...
, 1804