Leafcutter ants are social insects found in warmer regions of Central and South America. These unique ants have evolved an advanced agricultural system based on ant-fungus mutualism. They feed on special structures called gongylidia produced by a specialized fungus that grows only in the underground chambers of the ants' nest. Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Subclass Pterygota Infraclass Paleoptera (Probably paraphyletic) Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera (webspinners) Zoraptera (angel insects) Dermaptera (earwigs) Orthoptera (grasshoppers, etc) Phasmatodea (stick insects) Blattodea (cockroaches) Isoptera (termites) Mantodea (mantids) Psocoptera... For other uses, see Central America (disambiguation). ... South America South America is a continent crossed by the equator, with most of its area in the Southern Hemisphere. ... Ant-fungus mutualism is a verifiable symbiosis seen in certain ant and fungal species, where ants actively cultivate fungus much like humans farm crops as a food source. ... Subkingdom/Phyla Chytridiomycota Blastocladiomycota Neocallimastigomycota Glomeromycota Zygomycota Dikarya (inc. ... For other uses, see Ant (disambiguation). ... A basket style nest A nest is place of refuge built to hold an animals eggs and/or provide a place to raise their offspring. ...

Different species of leafc r ants use different species of fungus, but all of the fungi the ants use are members of the Lepiotaceae family. The ants actively cultivate their fungus, feeding it with freshly-cut plant material and maintaining it free from pests and molds. This symbiotic relationship is further augmented by another symbiotic partner, a bacterium that grows on the ants and secretes chemicals, or secondary metabolites, which protect the fungus from molds that would feed on the fungus - essentially the ants use portable antimicrobials. Leaf cutter ants are sensitive enough to adapt to the fungi's reaction to different plant material, apparantly detecting chemical signals from the fungus. If a particular type of leaf is toxic to the fungus the colony will no longer collect it. Genera Agaricus Allopsalliota Anellaria Barcheria Chamaemyces Chlamydopus Chlorophyllum Cystoagaricus Cystoderma Cystolepiota Endoptychum Gyrophragmium Lepista Lepiota Leucoagaricus Leucocoprinus Leucopholiota Longula Macrolepiota Melanophyllum Micropsalliota Montagnea Notholepiota Ripartitella Termiticola Tulostoma Verrucospora Volvolepiota Wikispecies has information related to: Agaricaceae Wikimedia Commons has media related to: Agaricaceae The Agaricaceae is a family of basidiomycete fungi... It has been suggested that Toxic mold be merged into this article or section. ... For other uses, see Symbiosis (disambiguation). ... Secondary metabolites, also known as natural products, are those products (chemical compounds) of metabolism that are not essential for normal growth, development or reproduction of an organism. ... An antimicrobial is a substance that kills or slows the growth of microbes like bacteria (antibacterial activity), fungi (antifungal activity), viruses (antiviral activity), or parasites (antiparasitic activity). ...

Leafcutter ants, Tikal, Guatemala. Photo credit: Wolf Levenson

Leafcutter ants comprise two genera — Atta and Acromyrmex — with a total of 39 species^[1] (15 in Atta and 24 in Acromyrmex), some of which are major agricultural pests. For example, some Atta species are capable of defoliating an entire citrus tree in less than 24 hours. Image File history File links Metadata No higher resolution available. ... Image File history File links Metadata No higher resolution available. ... For other uses, see Tikal (disambiguation). ... For other uses, see Genus (disambiguation). ... Species Many This article is about the genus of New World ants. ... For other uses, see Species (disambiguation). ...

The Acromyrmex and Atta ants have much in common anatomically; however, the two can be identified by their external differences. Atta ants have 3 pairs of spines and a smooth exoskeleton on the upper surface of the thorax while Acromyrmex have 4 pairs and a rough exoskeleton. [1] An exoskeleton is an external anatomical feature that supports and protects an animals body, in contrast to the internal endoskeleton of, for example, a human. ... Diagram of a tsetse fly, showing the head, thorax and abdomen The thorax is a division of an animals body that lies between the head and the abdomen. ...

A mature leafcutter colony can contain more than 8 million ants, mostly sterile female workers. They are divided into castes, based mostly on size, that perform different functions. Acromyrmex and Atta exhibit a high degree of biological polymorphism, four castes being present in established colonies - minims, minors, mediae and majors. Majors are also known as soldiers or dinergates. Atta ants are more polymorphic than Acromyrmex, meaning that there is comparatively less differential in size from the smallest to largest types of Acromymex. Caste systems are traditional, hereditary systems of social restriction and social stratification, enforced by law or common practice, based on endogamy, occupation, economic status, race, ethnicity, // 1555, a race of men, from L. casto chaste, from castus pure, cut off, separated, pp. ... In biology, polymorphism can be defined as the occurrence in the same habitat of two or more forms of a trait in such frequencies that the rarer cannot be maintained by recurrent mutation alone. ...

• Minims are the smallest workers, and tend to the growing brood or care for the fungus gardens. Head width is less than 1 mm.

• Minors are slightly larger minima workers and are present in large numbers in and around foraging columns. These ants are the first line of defense and continuously patrol the surrounding terrain and vigorously attack any enemies that threaten the foraging lines. Headwidth are around 1.8-2.2 mm

• Mediae are the generalized foragers, who cut leaves and bring the leaf fragments back to the nest.

• Majors are the largest worker ants and act as soldiers, defending the nest from intruders, although there is recent evidence that majors participate in other activities, such as clearing the main foraging trails of large debris and carrying bulky items back to the nest. The largest soldiers (Atta laevigata) may have total body lengths up to 16 mm and head widths of 7 mm.

When the ants are out collecting leaves, they are at risk of being attacked by the phorid fly, a parasitic pest which lay eggs into the crevices of the worker ants head. Often a minim will sit on the worker ant and ward off any attack. [2] Genera and Species Approximately 230 genera and 3000 species A phorid fly is a small, hump-backed fly of the highly diverse family Phoridae, and resembling a fruit fly in appearance. ... A parasite is an organism that spends a significant portion of its life in or on the living tissue of a host organism and which causes harm to the host without immediately killing it. ...

Atta colombica, queen with larvae and workers on substrate Image File history File links Download high resolution version (5472x3344, 885 KB) Description: Atta columbica queen with workers on substrate Source: own photo, Barro Colorado Island, Panama (1999) Photographer: Christian R. Linder Licence: File links The following pages link to this file: Leafcutter ant ...	Workers of Atta colombica cutting all leaves of a young tree Image File history File links Download high resolution version (2748x1764, 412 KB) Description: Workers of the species Atta columbica cutting down a whole plant. ...	Two leafcutter ants Image File history File links The_stronger_of_the_two. ...
ants collecting leaves. Image File history File links Leaf_cutters. ... Image File history File links Metadata No higher resolution available. ...	Leafcutter ants on job Image File history File links Leafcutter_ant_on_job. ...	Long way of leafcutter ant Image File history File links Long_way_of_leafcutter_ant. ...

See also

• Atta sexdens
• Lepiotaceae

Binomial name Atta sexdens (Linnaeus, 1758) Atta sexdens is a species of leafcutter ant belonging to the the tribe attini. ... Genera Agaricus Allopsalliota Anellaria Barcheria Chamaemyces Chlamydopus Chlorophyllum Cystoagaricus Cystoderma Cystolepiota Endoptychum Gyrophragmium Lepista Lepiota Leucoagaricus Leucocoprinus Leucopholiota Longula Macrolepiota Melanophyllum Micropsalliota Montagnea Notholepiota Ripartitella Termiticola Tulostoma Verrucospora Volvolepiota Wikispecies has information related to: Agaricaceae Wikimedia Commons has media related to: Agaricaceae The Agaricaceae is a family of basidiomycete fungi...

References

1. ^ Martin R Speight, Allan D Watt, Mark D Hunter (1999). Ecology of Insects. Blackwell Science Ltd., 156. ISBN 0-86542-745-3. 

External link

• http://www.bristolzoo.org.uk/learning/animals/invertebrates/ant