Mycocepurus smithii

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Geographic Range

Mycocepurus smithii inhabits the Neotropical region. This species is widely distributed throughout Central and South America, from Mexico through Argentina and also several islands in the Caribbean. (Fernandez-Marin, et al., 2005)

Habitat

Mycocepurus smithii is a fungus cultivating ant species, and thus inhabits moist soil ideal for growing fungus. Its nests can be found an average of 0.325 m below ground and consist of multiple connected chambers. This species may be found in savannas or rain forests that provide suitable soil conditions. (Fernandez-Marin, et al., 2005)

  • Range depth
    0.20 to 0.85 m
    0.66 to 2.79 ft
  • Average depth
    0.325 m
    1.07 ft

Physical Description

Mycocepurus smithii is roughly 3 mm long, and possess a fused mesonotum and pronotum, a promesonotum. A crown of spines on the promesonotum is unique to this genus and separates it from other ants. Mycocepurus smithii can be differentiated from other species in its genus by its lack of developed promesonotal spines in the center of its crown. Mycocepurus smithii can also be differentiated from other Mycocepurus ants by its sharp pronotal spines, which are generally shorter and more blunt in other species. This is an asexual species that is comprised of females only. (Mackay, et al., 2004; Rabeling, et al., 2009)

  • Average length
    3 mm
    0.12 in

Development

Mycocepurus smithii undergoes a complete metamorphosis including egg, larva, pupa, and adult stages in that order. Due to the parthenogenic nature of M. smithii, the sex of all offspring is female. (JRank Science & Philosophy, 2009)

Reproduction

Mycocepurus smithii appears to be a strictly asexual species of ant. Despite extensive testing no males have ever been discovered. All females in a given colony are clones of the queen, their mother. At this point, individuals of this species lack functional reproductive organs and thus the ability to reproduce. (Rabeling, et al., 2009)

Only queens reproduce; all other female workers are essentially sterile. In a related species, Mycocepurus goeldii, nests are prepared for reception of males and nuptial flights in late September, with mating occurring after the rains in early October. Such behaviors are not observed in M. smithii. Despite the lack of sexual activity in M. smithii, the peak production of alate females and nest founding occurs during the rainy season, July through September, similar to other species in its genus. Growth of M. smithii populations within a newly founded colony are markedly slower than in similar species, typically taking 2 to 5 months before the first workers are cited. (Fernandez-Marin, et al., 2005; Rabeling, et al., 2009)

  • Breeding interval
    Mycocepurus smithii reproduces once yearly.
  • Breeding season
    Mycocepurus smithii reproduces during the rainy season, which occurs from July through September.

All ant colonies show some degree of parental care. The initial brood in a colony is cared for by the queen. After a significant number of workers are born they then take over caring for the brood. The workers feed and protect the larvae for the remainder of their development. (Holldobler and Wilson, 1994)

  • Parental Investment
  • female parental care
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

Currently the lifespan of Mycocepurus smithii is unknown.

Behavior

Mycocepurus smithii, along with most other members of Formicidae exhibit eusociality. The workers help carry dry leaves and caterpillar droppings back to the nesting site. The nest helps house the fungal colony which the ants feed on. Mycocepurus smithii has a mutualistic relationship with the fungal colony. The fungus hangs in a suspended garden. The dry leaves and caterpillar droppings are used to nourish the fungal garden. When a queen leaves the colony, she may carry the fungus on her wings to help form a new colony. Mycocepurus smithii is composed entirely of females who undergo asexual reproduction. (Mackay, et al., 2004)

Home Range

Home range is currently unknown for this species.

Communication and Perception

Ants typically rely on communication via pheromones. Even though ants have eyes and antenna, which can be used for some communication, in a mainly subterranean colonial world the most efficient mode of communication is through pheromones. It has been estimated that ant species generally use between 10 and 20 chemical "words" to convey a message. The most recognizable signals that biologists can detect are attraction, recruitment, alarm, identification of other castes, recognition of larvae and other life stages, and discrimination between nestmates and strangers. (Holldobler and Wilson, 1994)

Food Habits

The fungus cultivating behavior in this species appears to provide the sole food source for Mycocepurus smithii. The queen of the colony maintains a symbiosis with the fungus. The queen must transport, nourish, and cultivate fungi with which she will nourish her brood. (Fernandez-Marin, et al., 2005)

  • Other Foods
  • fungus

Predation

Aside from local competitors, Mycocepurus smithii does not seem to have any specialized predators. Members of Formicidae usually exhibit anti-predatory behaviors, such as swarming and biting. Some ants even have specialized jaw appendages for biting and stinging. (Holldobler and Wilson, 1994)

Ecosystem Roles

Mycocepurus smithii are most notably known for their fungal cultivating mutualistic relationship. The fungal colonies serve as a food source for the ants and the ants help cultivate and grow fungal colonies. Mycocepurus smithii and other fungus cultivating ants provide an important ecological function in cultivating fungus. Mycocepurus smithii may help spread fungal colonies to newer habitats. (Fernandez-Marin, et al., 2005)

  • Ecosystem Impact
  • creates habitat
Mutualist Species
  • cultivated fungus Basidiomycota

Economic Importance for Humans: Positive

Currently there are no known positive effects of Mycocepurus smithii on humans.

Economic Importance for Humans: Negative

Currently there are no known adverse effects of Mycocepurus smithii on humans.

Conservation Status

Mycocepurus smithii is currently abundant and inhabits a large geographic range, making it a low conservation concern.

Contributors

Casey Schott (author), Rutgers University, Christian Strey (author), Rutgers University, David V. Howe (editor), Rutgers University.

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

asexual

reproduction that is not sexual; that is, reproduction that does not include recombining the genotypes of two parents

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

colonial

used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

eusocial

the condition in which individuals in a group display each of the following three traits: cooperative care of young; some individuals in the group give up reproduction and specialize in care of young; overlap of at least two generations of life stages capable of contributing to colony labor

female parental care

parental care is carried out by females

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

motile

having the capacity to move from one place to another.

mycophage

an animal that mainly eats fungus

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

parthenogenic

development takes place in an unfertilized egg

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

social

associates with others of its species; forms social groups.

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

References

Fernandez-Marin, H., J. Zimmerman, W. Wcislo, S. Rehner. 2005. Colony foundation, nest architecture and demography of a basal fungus-growing ant, Mycocepurus smithii (Hymenoptera, Formicidae). Journal of Natural History, 39(20): 1735-1743. Accessed November 11, 2009 at http://striweb.si.edu/publications/PDFs/Wcislo_Fernandez%20et%20all%20%282005%29%28J%20Nat%20Hist%29.pdf.

Holldobler, B., E. Wilson. 1994. Journey to the Ants. Cambridge, Massachusetts: The Belknap Press of Harvard University Press.

JRank Science & Philosophy, 2009. "Ants - Mating, Reproduction, and Life Span" (On-line). Science Encyclopedia. Accessed November 11, 2009 at http://science.jrank.org/pages/447/Ants-Mating-reproduction-life-span.html.

Mackay, W., J. Maes, P. Fernandez, G. Luna. 2004. The ants of North and Central America: the genus Mycocepurus (Hymenoptera: Formicidae).. Journal of Insect Science, 4:27: 7pp.. Accessed November 11, 2009 at http://www.insectscience.org/4.27/.

Rabeling, C., J. Lino-Neto, S. Cappellari, I. Dos-Santos, U. Mueller, M. Bacci Jr.. 2009. Thelytokous Parthenogenesis in the Fungus-Gardening Ant Mycocepurus smithii (Hymenoptera: Formicidae). PLoS One, 4(8): -. Accessed November 11, 2009 at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2728836/.