Ant mimicry

(Redirected from Myrmecomorph)

Ant mimicry or myrmecomorphy is mimicry of ants by other organisms; it has evolved over 70 times. Ants are abundant all over the world, and potential predators that rely on vision to identify their prey, such as birds and wasps, normally avoid them, because they are either unpalatable or aggressive. Some arthropods mimic ants to escape predation (Batesian mimicry), while some predators of ants, 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.

Top: An ant in Mozambique
Bottom: An ant-mimicking spider, Myrmarachne

In myrmecophily, mimic and model live commensally 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 pheromones, visually, or by imitating an ant's surface microstructure to defeat the ants' tactile inspections.

Types

edit

Batesian mimicry

edit
 
The thick waist of the Mirid ant bug, Myrmecoris gracilis, is camouflaged with white markings.[1]

Batesian mimics lack strong defences of their own, and make use of their resemblance to a well-defended model, in this case ants, to avoid being attacked by their predators. A special case is where the predator is itself an ant, so that only two species are involved.[2][3] The mimicry can be extremely close: for instance, Dipteran flies in the genus Syringogaster "strikingly" resemble Pseudomyrmex and are hard even for experts to distinguish "until they take flight".[4] Insects that do not share the narrow-waisted body plan of ants are sometimes elaborately camouflaged to improve their resemblance. For example, the thick waist of the Mirid ant bug Myrmecoris gracilis has white markings at the front of its abdomen and the back of its thorax, making it look ant-waisted.[1]

Over 300 spider species mimic the social behaviours, morphological features and predatory behaviour of ants. Many genera of jumping spiders (Salticidae) mimic ants.[5] 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.[6] 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 spider wasps and other larger jumping spiders.[7][8][9] 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.[8] A study of three species of mantises suggested that they innately avoided ants as prey, and that this aversion extends to ant-mimicking jumping spiders.[10]

Batesian mimicry of ants appears to have evolved even in certain plants, as a visual anti-herbivory strategy.[11] Passiflora flowers of at least 22 species, such as P. incarnata, have dark dots and stripes on their flowers for this purpose.[12]

Myrmecophily

edit
 
The cricket Myrmecophilus acervorum is a myrmecophile, resembling its ant hosts by touch, or perhaps by pheromones, but not visually.

Some arthropods are myrmecophiles, mimicking ants by non-visual means, including touch, behaviour, and pheromones. Many groups of myrmecophiles have convergently evolved similar features. They are not necessarily visual mimics of ants.[13] The mimicry allows them to live unharmed within ant nests, some beetles even marching with the aggressive Eciton burchellii army ants.[14] The Jesuit priest Erich Wasmann, who discovered ant mimicry, listed 1,177 myrmecophiles in 1894; many more such species have been discovered since then.[14]

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.[15][16] 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.[16]

Mites 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.[14] 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.[16]

The snail Allopeas myrmekophilos 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.[17]

Lycaenid butterflies

edit
 
Pupae of the lycaenid butterfly Phengaris rebeli in ant nest

Some 75% of lycaenid butterfly species are myrmecophiles, their larvae and pupae living as social parasites in ant nests.[18][19] [20][21] These lycaenids mimic the brood pheromone and the alarm call of ants so they can integrate themselves into the nest. In Aloeides dentatis the tubercles release the mimicking pheromone which deceives its host, the ant Acantholepis caprensis, into caring for the mimics as they would their own brood. In these relationships, worker ants give the same preference to the lycaenids as they do to their own brood, demonstrating that chemical signals produced by the mimic are indistinguishable to the ant. Larvae of the mountain Alcon blue, Phengaris rebeli, similarly mimic Myrmica ants and feed on their brood.[21]

Parasitoid wasps

edit

The parasitoid wasp Gelis agilis (Ichneumonidae) shares many similarities with the ant Lasius niger. G. agilis is a wingless wasp which exhibits multi-trait mimicry of garden ants, imitating the ant's morphology, behaviour, and surface chemicals that serve as pheromones, cuticular hydrocarbons.[22][23] When threatened it releases a toxic chemical similar to the ant's alarm pheromone. This multi-trait mimicry serves to protect G. agilis both from ants and (in Batesian mimicry) from ground predators such as wolf spiders.[24][22]

Aggressive mimicry

edit

Aggressive mimics are predators which resemble ants sufficiently to be able to approach their prey successfully. Some spiders, such as the Zodariidae and those in the genus Myrmarachne,[3] use their disguise to hunt ants. These ant hunters often do not visually resemble ants very closely.[25] Among the many spiders which are aggressive mimics of ants, Aphantochilus rogersi mimics its sole prey, Cephalotini ants. Like many other ant-mimicking spiders, it is also a Batesian mimic, gaining protection from predators such as spider-hunting wasps.[26]

Special protection for young insects

edit

Multiple groups of insects have evolved ant mimicry for their young, while their adults are protected in different ways, either being camouflaged or have conspicuous warning coloration.[2][27]

The young instars of some mantids, such as Odontomantis pulchra[28] 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.[29]

Young instars of some bush crickets in the genus Macroxiphus, have an "uncanny resemblance" to ants, extending to their black coloration, remarkably perfect antlike shape, and convincingly antlike behaviour.[2] 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.[2]

The phasmid 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 ant-dispersed (myrmecochoric) plant seeds, complete with a mimic oil body (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.[27]

Taxonomic range

edit

Ant mimicry has a wide taxonomic range, including some 2000 species of terrestrial arthropods in more than 200 genera. It has evolved over 70 times, including some 15 clades of spiders, 10 clades of plant-sucking bugs, and 7 clades of staphylinid rove beetles. Outside the arthropods, ant mimics include snails, snakes, and flowering plants.[14][13]

Eukaryotes

References

edit
  1. ^ a b Chinery, Michael (2005). Complete Guide to British Insects. Collins. pp. 96–97. ISBN 978-0-007-29899-0.
  2. ^ a b c d e Gwynne, Darryl T. (2001). Katydids and Bush-crickets: Reproductive Behavior and Evolution of the Tettigoniidae. Cornell University Press. p. 80. ISBN 978-0-8014-3655-0.
  3. ^ a b Viegas, Jennifer (15 November 2014). "More Than 300 Spiders Pretend to be Ants". Discovery. Archived from the original on 2 December 2014.
  4. ^ Marshall, S.A.; Buck, M.; Skevington, J.H.; Grimaldi, D. (2007). "A revision of the family Syringogastridae (Diptera: Diopsoidea)" (PDF). Zootaxa. 1996. Auckland, New Zealand: 1–80. doi:10.11646/zootaxa.1996.1.1. As noted by Papavero (1964), syringogastrids walking on leaves are strikingly similar to ants (especially Pseudomyrmex Lund) that often occur on the same leaf surfaces. They resemble ants in movement, size and shape (with the latter similarity enhanced by wing pigmentation), and can be difficult to distinguish from ants until they take flight.
  5. ^ McLean, Donald James; Herberstein, Marie E. (2021-06-09). "Mimicry in motion and morphology: do information limitation, trade-offs or compensation relax selection for mimetic accuracy?". Proceedings of the Royal Society B: Biological Sciences. 288 (1952): 20210815. doi:10.1098/rspb.2021.0815. PMC 8187996. PMID 34102888.
  6. ^ Shamble, Paul S.; Hoy, Ron R.; Cohen, Itai; Beatus, Tsevi (2017-07-12). "Walking like an ant: a quantitative and experimental approach to understanding locomotor mimicry in the jumping spider Myrmarachne formicaria". Proceedings of the Royal Society B: Biological Sciences. 284 (1858): 20170308. doi:10.1098/rspb.2017.0308. ISSN 0962-8452. PMC 5524487. PMID 28701553.
  7. ^ a b Huang, Jin-Nan; Cheng, Ren-Chung; Li, Daiqin; Tso, I.-Min (2011-05-07). "Salticid predation as one potential driving force of ant mimicry in jumping spiders". Proceedings of the Royal Society of London B: Biological Sciences. 278 (1710): 1356–1364. doi:10.1098/rspb.2010.1896. PMC 3061141. PMID 20961898.
  8. ^ a b Cushing, Paula E. (1997). "Myrmecomorphy and Myrmecophily in Spiders: A Review". The Florida Entomologist. 80 (2): 165–193. doi:10.2307/3495552. JSTOR 3495552.
  9. ^ Cutler, Bruce (May 1991). "Reduced predation on the antlike jumping spider Synageles occidentalis (Araneae: Salticidae)". Journal of Insect Behavior. 4 (3): 401–407. Bibcode:1991JIBeh...4..401C. doi:10.1007/bf01048287. S2CID 11200771.
  10. ^ Nelson, Ximena; et al. (April 2006). "Innate aversion to ants (Hymenoptera: Formicidae) and ant mimics: experimental findings from mantises (Mantodea)". Biological Journal of the Linnean Society. 88 (1): 23–32. doi:10.1111/j.1095-8312.2006.00598.x. hdl:10092/17559.
  11. ^ Weins, D. (1978). "Mimicry in plants". Evolutionary Biology. 11: 365–403.
  12. ^ a b c Lev-Yadun, Simcha (2009). "Ant mimicry by Passiflora Flowers?". Israel Journal of Entomology. 39: 159–163.
  13. ^ a b McIver, J. D.; Stonedahl, G. (1993). "Myrmecomorphy: Morphological and Behavioral Mimicry of Ants". Annual Review of Entomology. 38 (1): 351–377. doi:10.1146/annurev.en.38.010193.002031. ISSN 0066-4170.
  14. ^ a b c d e f g h i Kronauer, Daniel J. C.; Pierce, Naomi E. (2011-03-22). "Myrmecophiles". Current Biology. 21 (6): R208–R209. Bibcode:2011CBio...21.R208K. doi:10.1016/j.cub.2011.01.050. PMID 21419982.
  15. ^ 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
  16. ^ a b c d Hölldobler, Bert; Wilson, Edward O. (1990). The Ants. Harvard University Press. pp. 511–514. ISBN 978-0-674-04075-5.
  17. ^ Witte, V.; Janssen, R.; Eppenstein, A.; Maschwitz, U. (2002). "Allopeas myrmekophilos (Gastropoda, Pulmonata), the first myrmecophilous mollusc living in colonies of the ponerine army ant Leptogenys distinguenda (Formicidae, Ponerinae)". Insectes Sociaux. 49 (4): 301–305. doi:10.1007/PL00012646.
  18. ^ Pierce, Naomi E.; Braby, Michael F.; Heath, Alan; Lohman, David J.; Mathew, John; Rand, Douglas B.; Travassos, Mark A. (January 2002). "The Ecology and Evolution of Ant Association in the Lycaenidae (Lepidoptera)". Annual Review of Entomology. 47 (1): 733–771. doi:10.1146/annurev.ento.47.091201.145257. PMID 11729090. ProQuest 222345887.
  19. ^ DeVries, Philip J. (1992). "Singing Caterpillars, Ants and Symbiosis". Scientific American. 267 (4): 76–83. Bibcode:1992SciAm.267d..76D. doi:10.1038/scientificamerican1092-76. JSTOR 24939256.
  20. ^ a b Dettner, K.; Liepert, C. (1994). "Chemical mimicry and camouflage". Annual Review of Entomology. 39: 129–154. doi:10.1146/annurev.en.39.010194.001021.
  21. ^ a b Akino, T.; Knapp, J. J.; Thomas, J. A.; Elmes, G. W. (July 1999). "Chemical mimicry and host specificity in the butterfly Maculinea rebeli, a social parasite of Myrmica ant colonies". Proceedings of the Royal Society of London B: Biological Sciences. 266 (1427): 1419–1426. doi:10.1098/rspb.1999.0796. PMC 1690087.
  22. ^ a b c Malcicka, Miriama; Bezemer, T. Martijn; Visser, Bertanne; Bloemberg, Mark; Snart, Charles J. P.; Hardy, Ian C. W.; Harvey, Jeffrey A. (2015-01-27). "Multi-trait mimicry of ants by a parasitoid wasp". Scientific Reports. 5 (1): 8043. Bibcode:2015NatSR...5.8043M. doi:10.1038/srep08043. PMC 4306968. PMID 25622726.
  23. ^ Lorenzi, C.; Bagnères, A. G.; Clement, J. L. (1996). "The role of cuticular hydrocarbons in social insects: is it the same in paper-wasps". In Turillazzi, S.; West-Eberhard, M.J. (eds.). Natural History and Evolution of Paper Wasps. Oxford University Press. pp. 178–189.
  24. ^ Pasteur, G. (November 1982). "A Classificatory Review of Mimicry Systems". Annual Review of Ecology and Systematics. 13 (1): 169–199. Bibcode:1982AnRES..13..169P. doi:10.1146/annurev.es.13.110182.001125. JSTOR 2097066.
  25. ^ Murphy, Frances & Murphy, John (2000): "An Introduction to the Spiders of South East Asia". Malaysian Nature Society, Kuala Lumpur. Page 303
  26. ^ Oliveira, Paulo S.; Sazime, Ivan (June 1984). "The adaptive bases of ant-mimicry in a neotropical aphantochilid spider (Araneae: Aphantochilidae)". Biological Journal of the Linnean Society. 22 (2): 145–155. doi:10.1111/j.1095-8312.1984.tb01675.x.
  27. ^ a b c Compton, S. G.; Ware, A. B. (1991). "Ants disperse the elaisosome-bearing eggs of an African stick insect". Psyche: A Journal of Entomology. 98 (2–3): 207–214. doi:10.1155/1991/18258.
  28. ^ Ramesh, Aparajitha; Vijayan, Sajesh; Sreedharan, Sreethin; Somanathan, Hema; Uma, Divya (2016). "Similar yet different: differential response of a praying mantis to ant-mimicking spiders". Biological Journal of the Linnean Society. 119 (1): 158–165. doi:10.1111/bij.12793.
  29. ^ a b Prete, Frederick R. (1999). The Praying Mantids. JHU Press. pp. 297–298. ISBN 978-0-8018-6174-1.
  30. ^ a b Gullan, P. J.; Cranston, P. S. (2014). The Insects: An Outline of Entomology (5th ed.). John Wiley & Sons. p. 395. ISBN 978-1-4443-1767-1.
  31. ^ Mound, L.A.; Reynaud, P. (2005). "Franklinothrips; a pantropical Thysanoptera genus of ant-mimicking obligate predators (Aeolothripidae)" (PDF). Zootaxa. 864: 1–16. doi:10.11646/zootaxa.864.1.1.
  32. ^ Wheeler, William Morton (1931). "The Ant Camponotus (Myrmepomis) Sereceiventris Guerin and its Mimic" (PDF). Psyche: A Journal of Entomology. 38 (2–3): 86–98. doi:10.1155/1931/98237.
  33. ^ Pie, Marcio R.; Del-Claro, Kleber (2002). "Male-Male Agonistic Behavior and Ant-Mimicry in a Neotropical Richardiid (Diptera: Richardiidae)" (PDF). Studies on Neotropical Fauna and Environment. 37 (1): 19–22. Bibcode:2002SNFE...37...19P. doi:10.1076/snfe.37.1.19.2114. S2CID 84201196. Archived from the original (PDF) on 2021-01-23. Retrieved 2007-10-14.
edit