Acromyrmex crassispinus
Encyclopedia
Acromyrmex crassispinus 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 throughout South America
, especially in Argentina
and Paraguay
.
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 crassispinus colony contains more than 8 million ants, 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 buccal 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 crassispinus is black-brown in colour and their queens are 10 - 12 mm in size and their workers may ranges from 5 to 15 mm in size.
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 throughout South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, especially in Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
and Paraguay
Paraguay
Paraguay , officially the Republic of Paraguay , is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to the east and northeast, and Bolivia to the northwest. Paraguay lies on both banks of the Paraguay River, which runs through the center of the...
.
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 crassispinus colony contains more than 8 million ants, 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 buccal 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 crassispinus is black-brown in colour and their queens are 10 - 12 mm in size and their workers may ranges from 5 to 15 mm in size.
Synonyms
- Acromyrmex atratus 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 diabolica 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 insularis 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 mediocris 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 mesonotalis Forel, 1909
- Acromyrmex rufescens 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 rusticus 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