''Myrmeconema neotropicum'' is a tetradonematid

nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...

parasite. It appears to induce fruit mimicry in the tropical ant. Presently the only known host species is ''

Cephalotes atratus ''Cephalotes atratus'' is a species of arboreal ant in the genus ''Cephalotes'', a genus characterized by its odd shaped head. These ants are known as gliding ants because of their ability to "parachute" by steering their fall if they lose their ...

'', a

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 southe ...

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 22 ...

with a black

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...

. Upon

infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dise ...

, the gaster, or bulbous hindmost region of the

, resembles one of the many red berries found in tropical forest canopies.

Life cycle

''Myrmeconema neotropicum's'' life cycle begins when a bird eats the infected ant. Upon passing through the bird's digestive system the eggs are defecated out. The eggs are then picked up by the ants and fed to their larvae. Once inside the immature ant gut the eggs migrate to the gaster where they will fully mature. Once the ant larvae pupate the mature nematodes begin to reproduce inside of the gaster. The males expire soon after mating but the females hold the eggs within themselves. Once the ant develops into a young adult the gaster begins to become translucent, thus allowing the red embryos to be seen. The longer the ant is parasitized the redder the gaster becomes. The infected ant then travels outside now mimicking small red berries which are a favorite food of birds. The ant is confused for a berry and is eaten by the bird starting the whole cycle over again. Although bird predation on an infected ''Cephalotes atratus'' has not yet been observed, the combination of field experiments and the known natural history of the ant indicate that this is the most

parsimonious Occam's razor, Ockham's razor, or Ocham's razor ( la, novacula Occami), also known as the principle of parsimony or the law of parsimony ( la, lex parsimoniae), is the problem-solving principle that "entities should not be multiplied beyond neces ...

explanation for transmission of the parasite to new ant colonies.

Signs and symptoms

Infected ants develop bright red gasters, tend to be more sluggish, and walk with their gasters in a conspicuous elevated position. According to Jonathan (2011), infected gasters had 57% more mass, but 37% lower metabolic rates, compared to uninfected gasters. These changes likely cause

frugivorous A frugivore is an animal that thrives mostly on raw fruits or succulent fruit-like produce of plants such as roots, shoots, nuts and seeds. Approximately 20% of mammalian herbivores eat fruit. Frugivores are highly dependent on the abundance and ...

birds to mistake the infected ants for berries and eat them. Increased reddening coincides with a shift in ant behavior that includes foraging outside the nest, thus increasing the probability of consumption by a duped bird.

Morphology

Female ''Myrmeconema neotropicum'' mature within the gaster of the host ants. They are about 1 mm in length and about 112 μm at their greatest width. Males are smaller than females (680 μm in length and 97 μm in diameter) (Poinar & Yanoviak 2008). The infected young adult ant is completely black and spends most of its time tending brood within the nest. As the parasite embryos develop within the eggs, the ant gaster becomes translucent, ultimately appearing bright red.

References

* * *Yanoviak, S. P., M. Kaspari, R. Dudley, G. Poinar Jr. 2008. Parasite-induced fruit mimicry in a tropical canopy ant. The American Naturalist 171:4, 536–544. *Jonathan Z. Shik, Michael Kaspari, and Stephen P. Yanoviak (''2011''). Preliminary Assessment of Metabolic Costs of the Nematode Myrmeconema neotropicum on its Host, the Tropical Ant Cephalotes atratus. Journal of Parasitology: October 2011, Vol. 97, No. 5, pp. 958–959. *Evans, C. (2015, February 5). Parasitic Mind Control. Retrieved from http://www.sciencenutshell.com/parasitic-mind-controlmyrmeconema-neotropicum/ {{Taxonbar, from=Q1953495 Enoplea Parasitic nematodes of animals Parasites of Hymenoptera