Cyphomyrmex | |
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Cyphomyrmex rimosus worker | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hymenoptera |
Family: | Formicidae |
Subfamily: | Myrmicinae |
Tribe: | Attini |
Genus: | Cyphomyrmex Mayr, 1862 |
Type species | |
Cyphomyrmex minutus | |
Diversity [1] | |
41 species |
Cyphomyrmex is a genus of fungus-growing ants found primarily in South and Central America. However, some species do come up to the southern portion of North America. They grow a variety of fungi in the tribe Leucocoprineae. Most fungal gardens are grown in small nodules, some species to cultivate entire mycelium, though. Colonies are monogynous and are relatively small with about 100 workers on average. [2]
This genus is within the subfamily Myrmicinae and the tribe Attini . Cyphomyrmex is a more basal part of this phylogenetic relationship. With more recent phylogenetic studies, more derived genera are placed ahead of this genus, now making it sister to the genus Mycetophylax . [3] The fungi that are grown by attine ants, like Cyphomyrmex, follow similar diversification as their ant cultivators. [4] Also, chemicals used throughout the attine ants are derived from one another. So, those used by Cyphomyrmex provided a base plan for more complex mixtures that are found in higher genera, like Trachymyrmex . This helps to relate attine ants to one another and even separate species as chemical profiles can be particularly unique. [5]
The frontal carinae on the head form a shield which is quite diagnostic for this genus. On the mesosoma, there are a series of blunt tubercles lining it. This genus is divided into two complexes, the strigatus and rimosus complex. The strigatus complex is limited to South America, while the rimosus complex ranges from southern North America to South America. Species in the rimosus group can be noted by their anteriorly open antennal scrobe and the five teeth on their mandibles. While strigatus has a closed anterior antennal scrobe with six or more teeth on the mandibles. [6] [7]
As with all ants, they undergo complete metamorphosis. Their diet varies throughout development.
They are primarily mycophagous. [8] They are commonly groomed by workers which promotes fungal growth on their integument. This fungal growth can take both the mycelial and yeast form. As larvae develop through multiple instars, they do not differ drastically in their morphology. The main, observable difference is that they become larger and more rotund as they age. [9]
As is found across genera, as ant workers age they progressively move out of the colony. Younger workers are primarily nurses, while older ones are foragers. [10] [11] They also assist with ecdysis for the larvae as they molt or emerge from eggs. In Cyphomyrmex, workers are mostly mycophagous, like the larvae. Younger workers do receive sugary substances from older workers through trophallaxis. These older workers have the most diverse diet, consisting of sugary substances derived mostly from plants found from their foraging trips. [8]
Founding queens have a low level of fat reserves when compared to other genera. This is because they rely on their fungal gardens to provide these extra nutrients the first generation of workers will need. [12] There is normally a monogynous colony structure within Cyphomyrmex. The queen’s diet is primarily mycophagous, however some sugars are fed to her from the older, foraging workers. [8]
The rimosus group is known for their cultivation of nodules of fungus, also called yeast gardens. This type of growth is known for clusters of small patches of fungus on irregularly shaped nodules full of single-celled yeast-like cells. This type of growth is unique in association with Cyphomyrmex ants. So, it is thought of as a form of domestication for Leucocoprineaceous fungi as they naturally grow in the mycelium form. [13]
Workers grow nodules of fungus, in the tribe Leucocoprineae, [2] and they perform this in stages. First, workers will clean a portion of the ground and place insect feces, an old exoskeleton, or another organic item like a leaf. [2] [8] Then a worker will regurgitate fluids from her crop and add anal fluids. She then lets it dry on the surface. Other workers, or the same one, will repeat this process until the ball is about 0.8 mm. At this point, it is transplanted to where other nodules are growing with fungi. This new one is rubbed on established colonies and then placed on the ground, starting a new, small garden. [8] Gardens can also be created hanging from roots on the ceiling of a nest, showing plasticity in the behavior of nest making. [14]
Workers also can have highly aggressive behavior towards unwanted guests. Specialized wasps in the family Diapriidae parasitize larvae and can induce a relatively large mortality rate, with about 16% of all larvae being infected. Any newly emerged wasps found in the brood piles are almost immediately attacked. [15]
Most Cyphomyrmex species are found to contain 3-octanol. [16] [5] This is thought to act as an alarm signal across species. Traces of nonanal are also found within the genus. Another common chemical group are farnesenes. It contributes to trail following behaviors, and potentially more importantly, influences agriculture practices. Some of the nodule-making species contain low diversity and overall levels of farnesenes. While mycelium growers are found to have a high diversity of this chemical group in their gaster. The presence of farnesenes seems to be unique to Cyphomyrmex among the fungus-growing ants; however, other genera across the family Formicidae also possess it. [16]
Inquilines of Cyphomyrmex can influence the behavior of their hosts. As observed in host associations between C. cornutus and its social parasite Megalomyrmex mondabora, alkaloids in the venom of the parasite cause less aggressive behavior in their host. Sometimes C. cornutus even plays dead when they are stung or in contact with their parasite, showing that the venom has evolved to not be extremely toxic to them and simply manipulate social behavior. [17]
The fungi that the ants interact with can also produce important chemicals. Some fungal gardens can produce diketopiperazines, which has antifungal abilities. This is through to either protect the fungi or the ants from other potentially harmful species. Diketopiperazines are thought to possess some antibacterial and antiviral abilities too. [18]
Common nest sites for species can range from in the soil, under rotting logs, within hollow and dead twigs. Some species have specialized nesting habits, such as C. longiscapus. They create swallow nest-like structures that hang underneath overhangs. It is made of soil or clay. The main entrance leads directly to their fungal garden, which should leave them susceptible to desiccation; but they only live in moist habitats so their gardens remain wet. [2] Some inhabit arid environments while others are in wetter conditions, like C. longiscapus. Another species, C.transversus, was observed nesting inside and around dry coconuts. [14] Therefore, a variety of species can found colonies in a wide range of habitats and ecosystems.
They range from Central South America, reaching as south as Argentina. They also reach up into North America, stretching from Texas up to California and even east to Florida. [19]
Leafcutter ants, a non-generic name, are any of 47 species of leaf-chewing ants belonging to the two genera Atta and Acromyrmex, within the tribe Attini. These species of tropical, fungus-growing ants are all endemic to South and Central America, Mexico, and parts of the southern United States. Leafcutter ants can carry twenty times their body weight and cut and process fresh vegetation to serve as the nutritional substrate for their fungal cultivates.
Fungus-growing ants 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 which they later feed.
Myrmicinae is a subfamily of ants, with about 140 extant genera; their distribution is cosmopolitan. The pupae lack cocoons. Some species retain a functional sting. The petioles of Myrmicinae consist of two nodes. The nests are permanent and in soil, rotting wood, under stones, or in trees.
Ant–fungus mutualism is a symbiosis seen between certain ant and fungal species, in which ants actively cultivate fungus much like humans farm crops as a food source. There is only evidence of two instances in which this form of agriculture evolved in ants resulting in a dependence on fungi for food. These instances were the attine ants and some ants that are part of the Megalomyrmex genus. In some species, the ants and fungi are dependent on each other for survival. This type of codependency is prevalent among herbivores who rely on plant material for nutrition. The fungus’ ability to convert the plant material into a food source accessible to their host makes them the ideal partner. The leafcutter ant is a well-known example of this symbiosis. Leafcutter ants species can be found in southern South America up to the United States. However, ants are not the only ground-dwelling arthropods which have developed symbioses with fungi. A similar mutualism with fungi is also noted in termites within the subfamily Macrotermitinae which are widely distributed throughout the Old World tropics with the highest diversity in Africa.
Megalomyrmex is a genus of ant in the subfamily Myrmicinae. The genus is known only from the Neotropics, where some of the species are specialized parasites or predators of Attini.
Sericomyrmex is a genus of fungus-growing ants in the subfamily Myrmicinae.
Acromyrmex is a genus of New World ants of the subfamily Myrmicinae. This genus is found in South America and parts of Central America, México and the Caribbean Islands, and contains 33 known species. Commonly known as "leafcutter ants" they comprise one of the two genera of advanced attines within the tribe Attini, along with Atta.
Mycocepurus smithii is a species of fungus-growing ant from Latin America. This species is widely distributed geographically and can be found from Mexico in the north to Argentina in the south, as well as on some Caribbean Islands. It lives in a variety of forested habitats and associated open areas. Two studies published in 2009 demonstrated that some populations of the species consist exclusively of females which reproduce via thelytokous parthenogenesis. A detailed study found evidence of sexual reproduction in some populations in the Brazilian Amazon. Accordingly, M. smithii consists of a mosaic of sexually and asexually reproducing populations. In asexual populations all ants in a single colony are female clones of the queen. Inside the colony, the ants cultivate a garden of fungus grown with pieces of dead vegetable matter, dead insects, and insect droppings.
Mycocepurus is a Neotropical genus of fungus-growing ants in the subfamily Myrmicinae. The genus is known from Mexico, south to Brazil and Argentina. Like other attines, they primarily grow fungi of the tribe Leucocoprini. They use many different substrates for growing their fungi, from dry leaves and caterpillar dung to fruit matter. One of its species, Mycocepurus smithii, which lives in South America, reproduces by cloning – all ants in a colony are clones of the queen. M. castrator is a parasite of M. goeldii.
Procryptocerus is a Neotropical genus of gliding ants, with the ability to "parachute" by steering their fall if they drop off of the tree they're on.
Trachymyrmex is a genus of fungus-growing ants in the subfamily Myrmicinae. The genus is mainly tropical in distribution, with most species being found in Central and South America.
Apterostigma is a genus of New World ants of the subfamily Myrmicinae. Two species have been described from fossils preserved in Dominican amber, while the others are extant. They are fungus-growing ants, though, unlike the majority of other species in Attini who grow Lepiotaceae, some species have begun cultivating Tricholomataceae.
Proatta is a Southeast Asian genus of ants in the subfamily Myrmicinae. It contains the single species Proatta butteli, known from the Malay Peninsula, Borneo and Sumatra.
Megalomyrmex mondaboroides is a Neotropical species of ant in the subfamily Myrmicinae. Megalomyrmex mondaboroides occurs in lowland wet forest habitats in Panama and Costa Rica. Colonies have been collected in the nests of small attines, primarily Cyphomyrmex costatus and Apterostigma goniodes. In Costa Rica a worker was collected in a Winkler sample of sifted leaf litter.
Megalomyrmex adamsae is a Neotropical species of ants in the subfamily Myrmicinae. Megalomyrmex adamsae, known from Panama, is very similar to M. symmetochus, known from Costa Rica to Panama.
Megalomyrmex wettereri is a Neotropical species of ants in the subfamily Myrmicinae. Megalomyrmex wettereri is known from two lowland rainforest sites: Barro Colorado Island in Panama and La Selva Biological Station in Costa Rica.
Megalomyrmex silvestrii is a Neotropical species of ants in the subfamily Myrmicinae. Megalomyrmex silvestrii is widespread in the mainland Neotropics from Mexico to northern Argentina. This species occurs in moist to wet forest habitats, from sea level to 1100 m elevation. It nests in small chambers in rotten wood or opportunistically in other small cavities in the soil. Colonies have been found in small attine nests and alone, suggesting it is a facultative predator of small Attini.
Cyphomyrmex rimosus is a species of higher myrmicine in the family Formicidae. It is part of the tribe Attini, or fungus-growing ants.
Cyphomyrmex wheeleri, the fungus gardening ant, is a species of higher myrmicine in the family Formicidae. As the common name suggests, this species grows a diversity of fungi, including year-round cultivation of Cladosporium cladosporioides, Fusarium solani, and Nigrospora sphaerica.
Leucocoprinus gongylophorus is a fungus in the family Agaricaceae which is cultivated by certain leafcutter ants. Like other species of fungi cultivated by ants, L. gongylophorus produces gongylidia, nutrient-rich hyphal swellings upon which the ants feed. Production of mushrooms occurs only once ants abandon the nest. L. gongylophorus is farmed by leaf cutter ant species belonging to the genera Atta and Acromyrmex, amongst others.