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Ant mimicry or myrmecomorphy is mimicry of by other organisms, mainly . It has independently evolved over 70 times in different species. Ants are abundant all over the world, and potential that rely on vision to identify their prey, such as and , normally avoid them, because they are either unpalatable or aggressive. Some arthropods mimic ants to escape predation (Batesian mimicry), while some Myrmecophagy, especially spiders, mimic them anatomically and behaviourally in aggressive mimicry. Ant mimicry has existed almost as long as ants themselves; the earliest ant mimics in the fossil record appear in the mid-Cretaceous alongside the earliest ants.
Ant mimics can be myrmecophily, with the mimics and their ant models living commensalism together. In the case of ants, the mimic is an inquiline in the ants' nest. Such mimics may in addition be Batesian or aggressive mimics. To overcome ants' powerful defences, mimics may imitate ants chemically with ant-like , visually, or by imitating an ant's surface microstructure to defeat the ants' tactile inspections.
Over 300 spider species mimic the social behaviours, morphological features and predatory behaviour of ants. Many genera of Jumping spider mimic ants. Jumping spiders in the genus Myrmarachne are Batesian mimics which resemble the morphological and behavioural properties of ants to near perfection. These spiders mimic the behavioural features of ants such as adopting their zig-zag locomotion pattern. Further, they create an antennal illusion by waving their first or second pair of legs in the air. The slender bodies of these spiders make them more agile, allowing them to easily escape from predators. Studies on this genus have revealed that the major selection force is the avoidance of ants by predators such as and other larger jumping spiders. Ant mimicry has a cost, given the body plan of spiders: the body of spider myrmecomorphs is much narrower than non-mimics, reducing the number of eggs per eggsac, compared to non-mimetic spiders of similar size. They seem to compensate by laying more eggsacs over their lifetimes. A study of three species of mantidae suggested that they innately avoided ants as prey, and that this aversion extends to ant-mimicking jumping spiders.
Batesian mimicry of ants appears to have evolved even in certain plants, as a visual anti-herbivory strategy. Passiflora flowers of at least 22 species, such as P. incarnata, have dark dots and stripes on their flowers for this purpose.
The cricket Myrmecophilus acervorum was one of the earliest myrmecophiles to be studied; its relationship with ants was first described by the Italian naturalist Paolo Savi in 1819. Osservazioni sopra la Blarta acervorum di panzee. Gryllus Myrmocophilus nob. Memoria (inedita) del dott. Paolo Savi, con tavola in rame, Biblioteca Italiana ossia Giornale di letteratura scienze ed arti (1819), Volume 15, Fascicolo It has many ant species as hosts, and occurs in large and small morphs suited to large hosts like Formica and Myrmica, and the small workers of species such as Lasius. On first arriving in an ants' nest, the crickets are attacked by the workers, and are killed if they do not run fast enough. Within a few days, however, they adjust their movements to match those of their hosts, and are then tolerated. Mimicry appears to be achieved by a combination of social releasers (signals), whether by imitating the ants' solicitation (begging) signals with suitable behaviour or ant pheromones with suitable chemicals; Hölldobler and Wilson propose that Wasmannian mimicry, where the mimic lives alongside the model, be redefined to permit any such combination, making it essentially a synonym for myrmecophily.
are among the most speciose mimics of ants, and can occur in large numbers in an ant colony. A single colony of Eciton burchellii army ants may contain some 20,000 inquiline mites. The phoretic mite Planodiscus (Uropodidae) attaches itself to the tibia of its host ant, Eciton hamatum. The cuticular sculpturing of the mite's body as seen under the electron microscope strongly resembles the sculpturing of the ant's leg, as do the arrangements and number of the bristles (setae). Presumably, the effect is that when the ant grooms its leg, the tactile sensation is as it would be in mite-free grooming.
The snail Allopeas lives in colonies of the army ant Leptogenys distinguenda. The snails live in bivouacs of the ants except when the colony migrates, during which the ants carry along the snails. A. myrmekophilos feeds on the meat of animals killed by the ants.
a wingless Ichneumonidae
File:Lasius_Niger.jpg|Model: Lasius niger
Myrmarachne spider eating a queen ant
File:Aphantochilus rogersi 93056208.jpg|Both aggressive and Batesian mimicry:
Aphantochilus
Oecophylla smaragdina
File:Myrmarachne plataleoides female thailand.jpg|Mimic: Female Myrmarachne plataleoides resembles worker red weaver ant.
File:Myrmarachne plataleoides male thailand (cropped).jpg|Mimic: Male M. plataleoides resembles one red weaver ant worker carrying another.
The young instars of some mantids, such as Odontomantis and Tarachodes afzelii are Batesian mimics of ants. Bigger instars and adults of these mantids are not ant mimics, but are well-camouflaged predators, and in the case of Tarachodes, that eat ants.
Young of some Tettigoniidae in the genus Macroxiphus, have an "uncanny resemblance" to ants, extending to their black coloration, remarkably perfect antlike shape, and convincingly antlike behaviour. Their long antennae are camouflaged to appear short, being black only at the base, and they are vibrated like ant antennae. Larger instars suddenly change into typical-looking katydids, and are entirely nocturnal, while the adult has bright warning coloration.
The Phasmatodea Extatosoma tiaratum, resembling dried thorny leaves as an adult, hatches from the egg as a replica of a Leptomyrmex ant, with a red head and black body. The long end is curled to make the body shape appear ant-like, and the movement is erratic, while the adults move differently, if at all. In some species the eggs resemble myrmecochory plant seeds, complete with a mimic elaiosome (a "capitulum"). These eggs are collected by the ants, deceived in a different way, and taken to their nests. The capitulum is removed and eaten, leaving the eggs viable.
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