''Atta sexdens'' is a
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of
leafcutter ant
Leafcutter ants are fungus-growing ants that share the behaviour of cutting leaves which they carry back to their nests to farm fungus. Next to humans, leafcutter ants form some of the largest and most complex animal societies on Earth. In a few ...
belonging to the tribe
Attini, native to America, from the southern United States (Texas) to northern
Argentina
Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...
. They are absent from Chile. They cut leaves to provide a substrate for the
fungus
A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...
farms which are their principal source of food. Their societies are among the most complex found in
social insect
Eusociality (Ancient Greek, Greek 'good' and social) is the highest level of organization of sociality. It is defined by the following characteristics: cooperative Offspring, brood care (including care of offspring from other individuals), ove ...
s. ''A. sexdens'' is an ecologically important species, but also an agricultural pest. Other ''
Atta'' species, such as ''
Atta texana'', ''
Atta cephalotes'' and others, have similar behavior and ecology.
Description
Colony architecture
''A. sexdens'' colonies are primarily subterranean with a mound of excavated material on the surface. The diameter of the colony may reach 10 m with a depth of 6 m. The colonies contain up to 2000 chambers with a combined volume of more than 20 m
3. The two basic types of chambers are fungus farms and waste chambers. The farms contain the fungal culture which sustains the colony and hosts
larva
A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...
e and
pupa
A pupa (; : 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 their life cycle, the stages th ...
e. The waste chambers are located at the rim of the colony and are significantly larger. They are used to dispose used fungal culture and dead ants. A mature colony contains 5–8 million workers.
The colony often forms the centerpiece of a large jungle clearing. At the top of the mound are structures resembling sand castles surrounding hundreds of openings to the colony. Positioning the openings on top of these structures minimises the amount of rainwater flowing into the colony. The openings also have an important role in
air conditioning
Air conditioning, often abbreviated as A/C (US) or air con (UK), is the process of removing heat from an enclosed space to achieve a more comfortable interior temperature, and in some cases, also controlling the humidity of internal air. Air c ...
. As the ant activity and fungal
metabolism
Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the co ...
heat up the colony, hot air rises through the central passageways. Simultaneously, fresh
air
An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...
is drawn in from the openings at the rim of the colony.
Anatomy
''A. sexdens'' follows the basic body plan of ants fairly closely. They have sharp spikes or hooks rising from their heads and midsections to deter
predator
Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...
s. Another distinguishing feature is a relatively large, two-lobed head. Its purpose is to accommodate the large
muscle
Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...
s moving the well-developed
mandible
In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla).
The jawbone i ...
s.
In addition to the queen, the colony contains four castes of
sterile
Sterile or sterility may refer to:
*Asepsis, a state of being free from biological contaminants
* Sterile (archaeology), a sediment deposit which contains no evidence of human activity
*Sterilization (microbiology), any process that eliminates or ...
female workers, and seasonally some winged virgin queens and males:
*Soldiers are the physically largest worker caste, with a head width of 3 mm and well-developed sharp mandibles. They are completely dedicated to defence, and do not participate in the running of the colony. In the event of attack by a predator, the soldiers storm out of the nest and attempt to overpower the aggressor. Their bite can easily penetrate human skin. The soldier caste is expensive to maintain, so they are absent from young colonies with less than 100,000 workers.
*Forager-excavators are the second-largest caste, with an average head width of 2.2 mm. They are responsible for venturing out to cut pieces of leaves and carry them back to the colony to feed the fungus. They also excavate new chambers to the colony.
*Within-nest specialists have an average head width of 1.4 mm. They usually remain inside the colony, where they process the leaf material brought in by the foragers to a smaller form. They also dispose of waste, help the gardener-nurse caste to take care of larger larvae, and attend to the queen.
*Gardener-nurses have an average head width of 1 mm. They are the physically smallest caste, less massive than the larger, more robust soldiers by a factor of several hundred. Their tasks are to attend to the fungal culture and to the developing
eggs
An egg is an organic vessel in which an embryo begins to develop.
Egg, EGG or eggs may also refer to:
Biology
* Egg cell, the female reproductive cell (gamete) in oogamous organisms
Food
* Eggs as food
Places
* Egg, Austria
* Egg, Switzerland ...
, larvae, and
pupae
A pupa (; : 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 their life cycle, the stages th ...
.
*The queen is the largest ant in the colony, outweighing the smaller worker by a factor of 700. She is also the only member of the colony capable of reproducing. The queen resides in a special chamber, where she is continually fed, cleaned, and protected by workers. The queens have a lifespan of 10–20 years.
Considerable variation in size occurs within the castes, some of which may be related to the division of labour. Some researchers separate seven castes, while others dismiss the idea of caste altogether. The division of labour also depends on the age of the worker. Foraging expeditions are hazardous, so are handled by older, thus more expendable, members of the caste.
Development
''A. sexdens'', like all ants, has four stages of development:
egg
An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the ...
, larva, pupa, and adult.
Their developmental larval stages are observed associated with fungal hyphae, and possess unique morphological features, compared to other ants.
They are, like all
hymenopteran
Hymenoptera is a large order of insects, comprising the sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are parasitic.
Females typi ...
s, haplodiploid, meaning males are
haploid
Ploidy () is the number of complete sets of chromosomes in a cell (biology), cell, and hence the number of possible alleles for Autosome, autosomal and Pseudoautosomal region, pseudoautosomal genes. Here ''sets of chromosomes'' refers to the num ...
(one of each
chromosome
A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...
) and
females
An organism's sex is female (symbol: ♀) if it produces the ovum (egg cell), the type of gamete (sex cell) that fuses with the male gamete (sperm cell) during sexual reproduction.
A female has larger gametes than a male. Females and male ...
, including workers, are diploid (a pair of each chromosome). Sex is determined by the type of egg laid. Unfertilized
eggs
An egg is an organic vessel in which an embryo begins to develop.
Egg, EGG or eggs may also refer to:
Biology
* Egg cell, the female reproductive cell (gamete) in oogamous organisms
Food
* Eggs as food
Places
* Egg, Austria
* Egg, Switzerland ...
will turn out to be males, which are strictly used for mating and are short-lived. Fertilized eggs produce females. The caste of the resulting adult depends on environmental cues.
Three to four weeks after being laid, the egg hatches and a larva emerges. In ''Atta'' ants, the larvae are fed by secretions from gardener-nurse ants and
trophic egg A trophic egg is an egg (biology), egg whose function is not reproduction but nutrition; in essence, the trophic egg serves as food for offspring hatched from viable eggs. In most species that produce them, a trophic egg is usually an Fertilization, ...
s (unfertilized eggs used as food). The
larva
A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...
e, after an additional three to four weeks pupate. Their pupae are cocoonless, as are all of the subfamily
Myrmicinae
Myrmicinae is a subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily ...
. After three to four more weeks, the pupae hatch into adult workers.
''A. sexdens'' larvae grow embedded in the fungal garden. Despite being surrounded by food, they are incapable of feeding themselves. Their adult sisters constantly feed and clean them. This is not a primitive feature. On the contrary, only the most advanced ant societies can expend such lavish care to their offspring as required by ''Atta'' larvae.
All female eggs are identical when laid. The caste of the resulting worker is determined by the conditions, which are in turn regulated by adult workers. The most important factor is the quantity of food. The largest amount of food results in virgin queens, while slightly less food creates soldiers. A shortage of one caste causes the workers to produce more ants of that caste. A drastic reduction in the work force may cause the colony to revert to the caste structure of a young colony, which does not have soldiers.
Behavior
Foraging
''A. sexdens'' workers forage leaves up to a range of 60 m from the colony. The scouting workers leave behind a trail of
pheromone
A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...
s after they discover a source of suitable plant material. Other workers follow this trail to the leaves. They cut the plant material to pieces suitable for an individual ant to carry back to the colony.
Smaller workers sometimes ride on the leaf pieces while the foragers carry them. The purpose of this behavior is not known for certain, but may be to protect the exposed foragers from attacks by parasitic insects. These insects include flies of the family
Phoridae
The Phoridae are a family of small, hump-backed flies resembling fruit flies. Phorid flies can often be identified by their escape habit of running rapidly across a surface rather than taking flight. This behaviour is a source of one of their al ...
which lay their eggs on foragers. The resulting larvae eat the ants alive.
Fungus cultivation
''A. sexdens'', like all leafcutter ants, is mycophagic. They live in a symbiotic relationship with a fungus belonging to the
subphylum
In zoological nomenclature, a subphylum is a taxonomic rank below the rank of phylum.
The taxonomic rank of " subdivision" in fungi and plant taxonomy is equivalent to "subphylum" in zoological taxonomy. Some plant taxonomists have also used th ...
Basidiomycota
Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basi ...
. Leaves and other soft plant material brought into the nest by the foragers is chewed into a pulp and
fertilized
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a zygote and initiate its development into a new individual organism or off ...
with
faeces
Feces (also known as faeces American and British English spelling differences#ae and oe, or fæces; : faex) are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the ...
. A small piece of fungus is placed on this substrate. The gardener-nurse caste takes care of the cultivation, transplanting fungus onto fresh substrate and weeding out wrong species of fungus, such as a parasitic ''
Escovopsis
''Escovopsis'' is a genus of seven formally acknowledged parasitic microfungus species that rely on other fungi to be their hosts. This genus formally circumscribed with a single identified species in 1990; in 2013 three other species were ad ...
'', which sometimes can contaminate nests. They also use secretions from their
salivary gland
The salivary glands in many vertebrates including mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands ( parotid, submandibular, and sublingual), as well as hundreds of min ...
s and help form
antibiotic
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...
-producing ''
Streptomyces
''Streptomyces'', from στρεπτός (''streptós''), meaning "twisted", and μύκης (''múkés''), meaning "fungus", is the largest genus of Actinomycetota, and the type genus of the family Streptomycetaceae. Over 700 species of ''St ...
''
bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...
to keep their fungal gardens a strict
monoculture
In agriculture, monoculture is the practice of growing one crop species in a field at a time. Monocultures increase ease and efficiency in planting, managing, and harvesting crops short-term, often with the help of machinery. However, monocultur ...
.
The gardener-nurses also cut pieces of
mycelium
Mycelium (: mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Its normal form is that of branched, slender, entangled, anastomosing, hyaline threads. Fungal colonies composed of mycelium are fo ...
for the other castes to eat. In addition to the fungus, the ''A. sexdens'' adults feed on plant
sap
Sap is a fluid transported in the xylem cells (vessel elements or tracheids) or phloem sieve tube elements of a plant. These cells transport water and nutrients throughout the plant.
Sap is distinct from latex, resin, or cell sap; it is a s ...
. They are the only source of nutrition for the ants, apart from the
trophic egg A trophic egg is an egg (biology), egg whose function is not reproduction but nutrition; in essence, the trophic egg serves as food for offspring hatched from viable eggs. In most species that produce them, a trophic egg is usually an Fertilization, ...
s laid by the queen when the colony is young.
The identity of the fungus remains a mystery. It is known that they are a species of the
basidiomycete
Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basid ...
family
Lepiotaceae
The Agaricaceae are a family of basidiomycete fungi and include the genus ''Agaricus'', as well as basidiomycetes previously classified in the families Tulostomataceae, Lepiotaceae, and Lycoperdaceae.
Taxonomy
The family Agaricaceae was publishe ...
. Some researchers believe all
fungus-growing ants
Fungus-growing ants (tribe Attini) comprise all the known fungus-growing ant species participating in ant–fungus mutualism. They are known for cutting grasses and leaves, carrying them to their colonies' nests, and using them to grow fungus on ...
cultivate just one species, ''
Leucocoprinus
''Leucocoprinus'' is a genus of fungi in the family Agaricaceae. Its best-known member is the distinctive yellow mushroom ''Leucocoprinus birnbaumii'', which is found in plant pots and greenhouses worldwide. The type species is ''Leucocoprinus ce ...
gongylophorus''. The fungus produces special structures, called
gongylidia
Gongylidia (singular gongylidium) are hyphal swellings of fungus cultivated by higher-attine genera of fungus-growing ants. This fungus no longer exists naturally outside the ant colonies.
Developing larvae feed on the gongylidia and distribu ...
, which have
evolved
Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...
to be eaten by ants.
Cleaning
''A. sexdens'' workers spend a considerable time cleaning each other and the queen. They also spread antibiotic secretions from their
metapleural gland
Metapleural glands (also called metasternal or metathoracic glands) are secretory glands that were considered unique to ants and basal in the evolutionary history of ants. They are responsible for the production of an antibiotic fluid that then col ...
s on their bodies. Dirt collected by licking is stored in the workers'
infrabuccal cavities, which are special recesses in their mouths. The purpose of these activities is to avoid infections, especially by
parasitic
Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The ent ...
fungi. Several fungus species, such as ''
Cordyceps
''Cordyceps'' is a genus of ascomycete fungi (sac fungi) that includes over 260 species worldwide, many of which are parasitic. Diverse variants of cordyceps have had more than 1,500 years of use in Chinese medicine. Most ''Cordyceps'' specie ...
'', specially infect and kill ants.
All waste in the nest, including infrabuccal pellets, spent substrate from the gardens, and dead ants are carried in the waste chambers to avoid contamination.
Feces
Feces (also known as faeces American and British English spelling differences#ae and oe, or fæces; : faex) are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the ...
, however, are not carried away, but used to fertilise the fungal gardens. The waste chambers are larger than the human head and located at the rim of the colony. There, the waste can decompose without endangering the ants. Due to the high concentration of various
nutrient
A nutrient is a substance used by an organism to survive, grow and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi and protists. Nutrients can be incorporated into cells for metabolic purposes or excret ...
s in the decomposing waste, a thick net of plant
root
In vascular plants, the roots are the plant organ, organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often bel ...
s usually permeates the
compost
Compost is a mixture of ingredients used as plant fertilizer and to improve soil's physical, chemical, and biological properties. It is commonly prepared by Decomposition, decomposing plant and food waste, recycling organic materials, and man ...
.
Reproduction
From late October to mid-December, the ''A. sexdens'' colonies produce winged virgin queens and males. Before the
nuptial flight
Nuptial flight is an important phase in the reproduction of most ant, termite, and some bee species. It is also observed in some fly species, such as '' Rhamphomyia longicauda''.
During the flight, virgin queens mate with males and then land ...
, young queens visit the colony's fungal gardens and place a small piece of fungal
mycelium
Mycelium (: mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Its normal form is that of branched, slender, entangled, anastomosing, hyaline threads. Fungal colonies composed of mycelium are fo ...
in their infrabuccal cavities. During their nuptial flights, the queens mate with several males, which die shortly after. The queen retains the
sperm
Sperm (: sperm or sperms) is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm ...
in a special organ for the rest of her life.
It is estimated that each queen is inseminated by 3-8 males and that the number of fathers per colony is between 1 and 5.
The mated queen lands on the ground and tears off her now-unnecessary
wings
A wing is a type of fin that produces both lift and drag while moving through air. Wings are defined by two shape characteristics, an airfoil section and a planform. Wing efficiency is expressed as lift-to-drag ratio, which compares the bene ...
. Then she digs a vertical tunnel to a depth of about 30 cm. At the end of the tunnel, she excavates a small chamber. The queen then starts a fungal garden using the piece brought from her birth colony. Usually, the garden is fertilized only with feces, but sometimes it is necessary for the queen to forage a small quantity of plant material. The queen also lays a few eggs.
The queen then tends to the fungal garden and the developing larvae, feeding them fungus and
trophic egg A trophic egg is an egg (biology), egg whose function is not reproduction but nutrition; in essence, the trophic egg serves as food for offspring hatched from viable eggs. In most species that produce them, a trophic egg is usually an Fertilization, ...
s. The queen herself eats nothing during this period, sustaining herself on fat deposits and her shrinking flight
muscle
Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...
s. After the first brood of workers is ready, they take over the running of the fledgling colony and the queen becomes strictly an egg-laying machine. This process takes 40–60 days.
At first, the colony grows slowly, but after two to three years, the growth becomes faster. One possible reason for this is, before the colony is established enough to sustain any large soldier-caste workers, it is useful to remain unnoticed. Soldiers usually appear when the colony has a population of about 100,000. After the number of workers reaches 5–8 million, the colony stops expanding and diverts resources into producing queens and males.
The virgin queens are very rarely successful. Assuming the number of colonies in an area remains constant over time, on average only one queen among the many thousands sent out by a colony successfully founds a new one. However, a mature colony of several million workers faces very few dangers. No known predator, except the mostly subterranean army ant ''
Nomamyrmex
''Nomamyrmex'' is a genus of army ants in the subfamily Dorylinae. Its two species are distributed in the Neotropics: ''Nomamyrmex esenbeckii'' is known from southern United States to northern Argentina, and ''Nomamyrmex hartigii'' is known from ...
esenbeckii'', actively attacks the nests, and even other highly aggressive
army ant
The name army ant (or legionary ant or ''marabunta'') is applied to over 200 ant species in different lineages. Because of their aggressive predatory foraging groups, known as "raids", a huge number of ants forage simultaneously over a limited ...
s show a healthy respect for an ''A. sexdens'' colony. If spared from floods and human activity, the colony is usually destroyed only when the queen dies of old age, giving a successful colony a lifespan of 10–20 years. In that time, the colony will have sent out numerous males and virgin queens to found new colonies.
Significance
Ecological impact
At the end of its lifespan, an ''A. sexdens'' colony has moved up to 40,000 kg of
soil
Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...
. This has two important results: The soil becomes aerated with the excavation of tunnels and chambers, and enriched with
nutrient
A nutrient is a substance used by an organism to survive, grow and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi and protists. Nutrients can be incorporated into cells for metabolic purposes or excret ...
s as the ants bury their waste products. This represents a major way in which nutrients are recycled in their environment.
''A. sexdens'' and other leafcutter ants are also important
herbivore
A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...
s, consuming 12–17% of the leaf mass-produced in
neotropical
The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone.
Definition
In biogeogra ...
rainforest
Rainforests are forests characterized by a closed and continuous tree Canopy (biology), canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropi ...
s. One colony's consumption of plant material is comparable to that of a large
mammalian
A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...
herbivore, such as a cow. ''A. sexdens'' and the related species, ''A. cephalotes'' are the principal
insect
Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...
pests where they are found, destroying billions of dollars worth of crops with their ability to quickly defoliate and strip crops of anything useful to the ants. In fact, ''Atta'' ants are considered the primary herbivorous pest in many areas where they are found.
[Wilson, E., B. Holldobler. 1994. Journey to the Ants. Cambridge, Massachusetts: Kelknap Press of Harvard University Press.]
If ''A. sexdens'' were to spread into
tropical
The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...
Africa, the results are speculated to be devastating. As the local plants have not developed defensive compounds against leafcutters and Africa does not have
parasite
Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...
s evolved to infect them, the results for both the
ecosystem
An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...
and
agriculture
Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created ...
would be disastrous.
References
External links
*
{{Taxonbar, from=Q1957629
Atta (genus)
Insects described in 1758
Hymenoptera of South America
Hymenoptera of North America
Taxa named by Carl Linnaeus