''Azteca andreae'' is an

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose nu ...

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of ...

species found in the

tropics The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referr ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...

, most notably in

French Guiana French Guiana ( or ; french: link=no, Guyane ; gcr, label=French Guianese Creole, Lagwiyann ) is an overseas department/region and single territorial collectivity of France on the northern Atlantic coast of South America in the Guianas. ...

. They are most notable for their

predatory Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

skills and strength. They are

ambush predator Ambush predators or sit-and-wait predators are carnivorous animals that capture or trap prey via stealth, luring or by (typically instinctive) strategies utilizing an element of surprise. Unlike pursuit predators, who chase to capture prey ...

s that are able to capture and eat other

insects Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of j ...

much greater than their own size.

Physical characteristics

''A. andreae'' have dark brown, shiny bodies covered in white hair. The workers are a little less than 3mm in length, and the

queen Queen or QUEEN may refer to: Monarchy * Queen regnant, a female monarch of a Kingdom ** List of queens regnant * Queen consort, the wife of a reigning king * Queen dowager, the widow of a king * Queen mother, a queen dowager who is the mother ...

is slightly more than 5mm in length.Guerrero R., Delabie J., Dejean A. (2010) "Taconomic contribution to the aurita group of the ant genus Azteca (Formicidae: Dolichoderinae)." J. Hym. Res. 19 (1):51-65

Habitat

The ants live in the hollow internodes, or the spaces in between nodes on the

plant stem A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, stores nut ...

, of select plant species. When the queens start a new

colony In modern parlance, a colony is a territory subject to a form of foreign rule. Though dominated by the foreign colonizers, colonies remain separate from the administration of the original country of the colonizers, the '' metropolitan state' ...

, they apparently limit their colonies to ''

Cecropia ''Cecropia'' is a Neotropical genus consisting of 61 recognized species with a highly distinctive lineage of dioecious trees. The genus consists of pioneer trees in the more or less humid parts of the Neotropics, with the majority of the speci ...

'' trees. They will inhabit multiple different species of tree, but they have a preference for ''Cecropia obtusa''. Up to 8350 workers live in each tree. The queens initially start the colonies inside of the

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

, but the ants will eventually build external carton

nest A nest is a structure built for certain animals to hold eggs or young. Although nests are most closely associated with birds, members of all classes of vertebrates and some invertebrates construct nests. They may be composed of organic materi ...

s.Dejean A., Leroy C., Corbara B., Roux O., Céréghino R., Orivel J., Boulay R. (2010) "Arboreal ants use the 'Velcro Principle' to capture very large prey." . PLoS ONE 5(6): e11331. The ants will also build their nests near the wasp species ''

Polybia rejecta ''Polybia rejecta'' is a species of social wasp found in the Neotropics region of the world. It was discovered by Fabricius in South America in the 1790s. The wasp is associated with many other organisms, particularly specific species of ants ...

'' in order to protect the nests from other predators. The wasp is highly aggressive towards any mammal or other predator that approaches their nest.

Plant-ant symbiosis

Often, the ants will not only receive housing from the plant; they will eat extrafloral nectar and food bodies that the plant provides. In return, the plant receives security from

herbivores A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

that may eat the plant, because the ants hunt on the plant and eat many of the plant’s predators. This symbiosis benefits both the plant and ants.

Predatory behavior

''A. andreae'' use ambush predation to hunt insects many times their own size. The ants will actually position themselves side-by-side next to each other underneath the edge a

leaf A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...

. There, they are invisible from above except for their

mandibles In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

, which hang outside the edge waiting for prey. Many times, the ants will occupy each leaf of the plant. When an insect lands on the leaf, three to ten of the closest ants immediately attack and drive the prey to the leaf margin, where more ambushing ants will congregate and attack. Large prey was only captured if on the edge of the leaf, because the ants use their specialized

leg A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element ca ...

s to hold onto the velvety surface underneath ‘’C. obtusa’’ leaves. This mechanism essentially acts like

Velcro Velcro, officially known as Velcro IP Holdings LLC and trading as Velcro Companies, is a British privately held company, founded by Swiss electrical engineer George de Mestral in the 1950s. It is the original manufacturer of hook-and-loop fast ...

, with the many small hooks on the legs of the ant gripping onto the velvet of the underside of the leaf. Because only the bottom of the leaf has this surface, the ants can only really capture prey when they are holding onto the leaf from the underside. This is the main factor that allows the ants to capture such massive prey. After catching their prey, they will either start tearing it to shreds on the spot or take it back to the colony and cut it up into smaller pieces. In an experiment by Alain Dejean et al. (2010), the ants captured more prey when hunting on ''C. obtusa'' than any other plant. The proposed explanation for this was the enhanced gripping power resulting from the Velcro-like mechanism that was absent on all the other plants. In addition, the research team tested the limits of the ants’ strength. They placed a weight on a thread, which they introduced to an ant that immediately grabbed on to the thread with its mandibles. An individual ant held onto weights up to eight grams, or 5,714 times the ant’s weight. Collectively, they were observed to capture a

locust Locusts (derived from the Vulgar Latin ''locusta'', meaning grasshopper) are various species of short-horned grasshoppers in the family Acrididae that have a swarming phase. These insects are usually solitary, but under certain circumstanc ...

that weighed 18.61 grams, or 13,350 times the average weight of a single worker. This is one of the largest feats of strength documented in the entire animal world.

References

External links

Youtube video of ''A. andreae'' ants ambushing a moth

"Arboreal Ants Use the 'Velcro® Principle' to Capture Very Large Prey" Article

"Taxonomic Contribution to the aurita Group of the Ant Genus Azteca (Formicidae: Dolichoderinae)" Article

{{Taxonbar, from=Q4832981

andreae Andreae is a surname. The name may refer to: * Andreae & Co., a historical pharmacy in Hanover * Charles Andreae (1906–1970), English cricketer *Giles Andreae (born 1966), British poet, artist, and greeting card writer * Hieronymus Andreae (died ...

Hymenoptera of South America Insects described in 2010