Phragmosis

Last updated

Phragmosis is any method by which an animal defends itself in its burrow, by using its own body as a barrier. [1] This term was originally coined by W.M. Wheeler (1927), while describing the defensive technique exhibited by insects. [2] Wheeler observed the positioning of specially modified body structures to block nest entrances, as exhibited in various insect species. [2] The term phragmosis has since been further extended beyond just insects.

Contents

Examples of phragmosis are found in the order Anura (frogs and toads). Some species, such as Pternohyla fodiens and Corythomantis greeningi , have evolved a peculiarly casqued head adapted to protect the animal as it backs down a hole. [3] Another example is the head-plug defense used by the aphid Astegopteryx sp., in which a banana-bunch shaped gall consisting of several subgalls is used as a barrier. [4] Arguably, the most commonly observed phragmotic behaviour is within the ant family. [2] The behaviour is displayed in numerous taxa such as Camponotus , Colobostruma , Crematogaster , Pheidole , Blepharidatta , Cephalotes pusillus , Carebara elmenteitae, Stenamma expolitum , in which the soldiers have unusually large, disc-shaped heads, which are used to block nest entrances against intruders. [1]

In Anura

Corythomantis greeningi

Anurans involve a diverse group of largely carnivorous, short-bodied, tailless amphibians. Within this group, some frogs are characterized by a peculiar casqued head, with the skin co-ossified with the underlying bones. This type of skull is generally associated with phragmotic behaviour, where the animal will enter a hole and block the entrance with its head. [3]

Recent studies of Corythomantis greeningi , a casque-headed tree frog from semi-arid areas, have provided substantial information regarding the water economy associated with co-ossification of the head. [3] Due to the arid environments of most casque-headed anurans, it has been proposed that head co-ossification, together with phragmotic behaviour confer protection against water loss. Upon further investigation, it has been found that cranial co-ossification contributes little to conservation of water, but instead has a primary role of defence. This type of skull morphology primarily acts to protect the animal against predators, and in doing so, leads to an indirect enhancement of water balance within the body. [3]

In the study conducted by Jared et al. (1999) and Navas, Jared & Antoniazzi (2002), C. greeningi demonstrated the ability to enter test tubes backwards and close the entrance with their heads, a behaviour termed 'experimental phragmosis'. The study found that while phragmotic behaviour does not provide a significant reduction in water evaporation, it is important for preventing desiccation. [3] It was concluded that in C. greeningi , the co-ossified head likely evolved originally as a protective lid for phragmotic individuals, but does aid in reducing water permeability through the head. [3]

Pternohyla fodiens

The Mexican hylid casque-headed frog, Pternohyla fodiens, utilizes the head casque to close the entrance of its refuge in a tree cavity by deflecting the head. Due to their frequent foraging on the ground, this species often makes use of vertical burrows already extant in the ground layer as well. Upon arrival of intruder, P. fodiens assumes an immobile position – the head tipped back, with the entire body assumed in a gentle arch. The eyes close tightly, fore-legs are brought forward and upward, and hind-legs are flexed upward. By exhibiting the phragmotic habit during this interaction, it is more likely to effectively avoid predation. [5]

In gall-forming aphids

Aphid gall on Ulmus minor Eriosoma aphid gall on Ulmus minor - Flickr - S. Rae.jpg
Aphid gall on Ulmus minor

The aphid Astegopteryx sp. exhibits a head-plugging defense by forming a banana-bunch shaped gall, consisting of several subgalls, on Styrax benzoin. The soldier aphids of Astegopteryx are characterized by their sclerotic, protruded heads, covered in many spine-like setae. Several soldiers cooperate with one another to plug the ostiole of the subgall, utilizing their specialized morphology. [4]

In a study by Kurosu et al. (2005), of 173 ostioles examined, 90.8% were plugged, with no space among the guarding soldiers. [4] Of the 90.8% plugged ostioles, several male intruders were found outside the phragmotic plug, attempting to enter. [4] All intruders were blocked by the guarding soldiers, and it was nearly impossible to enter the subgall. [4]

Astegopteryx soldiers effectively defend their subgall by plugging the ostiole nearly completely with their sclerotic, spiny heads, which are very likely to have evolved for that purpose. [4]

In ants

Ant queen excavating hole Meat eater ant qeen excavating hole02.jpg
Ant queen excavating hole

Phragmotic-headed ants prevent intruders from entering nests by blocking the entrances, or by pushing them out of entrance galleries. Within the Neotropical species, Blepharidatta conops, queens are characterized by shield-like heads, and appear to secrete fibrous material. The material acts as a coating and eventually accumulates into a dense tangle of material, creating a disk over the head. When nests are visited, or inhabited by predators (especially beetles), the entrance is quickly blocked by the peculiar phragmotic disk of the queen. This modification of the body enables the queen to act as a living gate to the brood chamber. [2]

Phragmosis in ants has evolved independently in the diverse ant genera Camponotus Mayr (Hypercolobopsis), Colobopsis Mayr, Cephalotes Latreille, [6] Colobostruma Wheeler (C. leae), Crematogaster Lund (Colobocrema), Pheidole Westwood (P. colobopsis, P. lamia), but also in other genera, such as Blepharidatta Smith, (B. conops), Tetraponera Smith (T. phrag- motica) and Carebara Westwood. [7] The behaviour is most developed in the genus Cephalotes, where all castes (both queens and workers), have highly adapted head morphologies. [7] The shield-like armor which characterizes this behaviour enables plugging of nest entrances, without exposing eyes, antenna or mandibles to any potential intruders. [7]

Cyclocosmia truncata Cyclocosmia truncata.jpg
Cyclocosmia truncata

In spiders

The trapdoor spider Cyclocosmia has an abdomen ending in a hardened disc that it uses to plug the entrance to its burrow. [8]

Related Research Articles

<span class="mw-page-title-main">Ant</span> Family of insects

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 22,000 species have been classified. They are easily identified by their geniculate (elbowed) antennae and the distinctive node-like structure that forms their slender waists.

<span class="mw-page-title-main">Trophallaxis</span> Transfer of food between members of a community through stomodeal or proctodeal means

Trophallaxis is the transfer of food or other fluids among members of a community through mouth-to-mouth (stomodeal) or anus-to-mouth (proctodeal) feeding. Along with nutrients, trophallaxis can involve the transfer of molecules such as pheromones, organisms such as symbionts, and information to serve as a form of communication. Trophallaxis is used by some birds, gray wolves, vampire bats, and is most highly developed in eusocial insects such as ants, wasps, bees, and termites.

<i>Atta</i> (ant) Genus of ants

Atta is a genus of New World ants of the subfamily Myrmicinae. It contains at least 17 known species.

Autothysis or suicidal altruism is the process where an animal destroys itself via an internal rupturing or explosion of an organ which ruptures the skin. The term was proposed by Ulrich Maschwitz and Eleonore Maschwitz in 1974 to describe the defensive mechanism of Colobopsis saundersi, a species of ant. It is caused by a contraction of muscles around a large gland that leads to the breaking of the gland wall. Some termites release a sticky secretion by rupturing a gland near the skin of their neck, producing a tar effect in defense against ants.

<i>Cephalotes</i> Genus of ants

Cephalotes is a genus of tree-dwelling ant species from the Americas, commonly known as turtle ants. All appear to be gliding ants, with the ability to "parachute" and steer their fall so as to land back on the tree trunk rather than fall to the ground, which is often flooded.

<span class="mw-page-title-main">Banded sugar ant</span> Species of carpenter ant (Camponotus consobrinus)

The banded sugar ant, also known as the sugar ant, is a species of ant native to Australia. A member of the genus Camponotus in the subfamily Formicinae, it was described by German entomologist Wilhelm Ferdinand Erichson in 1842. Its common name refers to the ant's liking for sugar and sweet food, as well as the distinctive orange-brown band that wraps around its gaster.

<i>Corythomantis greeningi</i> Species of amphibian

Corythomantis greeningi, occasionally called Greening's frog, is a venomous frog species in the family Hylidae endemic to eastern Brazil, where it lives in Caatinga habitat. It is usually situated on vegetation, including in bromeliads, and on rock outcrops. Breeding occurs in temporary streams. Although suffering from habitat loss, it is not considered threatened by the IUCN. The specific name greeningi was in honour of Linnaeus Greening (1855–1927), an English businessman and naturalist known for his work on arachnids, reptiles and amphibians.

<i>Lithodytes</i> Genus of amphibians

Lithodytes is a genus of frogs in the family of Leptodactylidae. It is monotypic, being represented by the single species, Lithodytes lineatus, also commonly known as the gold-striped frog or painted antnest frog. It is found in tropical South America where it lives in humid forests among the leaf litter. These frogs build foam nests at the edge of temporary pools, and the tadpoles develop within these. The frogs also associate with certain leafcutter ants and breed inside their nests without being attacked by the ants.

Myrmecia inquilina is a species of ant endemic to Australia in the subfamily Myrmeciinae, first discovered in 1955 and described by Athol Douglas and William Brown Jr. in 1959. These ants are large, measuring 21.4 millimetres (0.84 in). During the time of its discovery, Douglas and Brown announced M. inquilina as the first social parasite among the primitive subfamilies, and today it is one of the two known Myrmecia species to have no worker caste. Two host species are known, Myrmecia nigriceps and Myrmecia vindex. Aggression between M. inquilina and its host species does not occur, and colonies may only produce M. inquilina brood months after the inquiline queens begin to lay their eggs. Queens eat the colony brood or trophic eggs, and other Myrmecia species may kill M. inquilina queens if they reject them. Due to its restricted distribution and threats to its habitat, the ant is "vulnerable" according to the IUCN Red List.

Task allocation and partitioning is the way that tasks are chosen, assigned, subdivided, and coordinated within a colony of social insects. Task allocation and partitioning gives rise to the division of labor often observed in social insect colonies, whereby individuals specialize on different tasks within the colony. Communication is closely related to the ability to allocate tasks among individuals within a group. This entry focuses exclusively on social insects. For information on human task allocation and partitioning, see division of labour, task analysis, and workflow.

<i>Carebara diversa</i> Species of ant

Carebara diversa, the East Indian harvesting ant, is a species of marauder ant widely distributed throughout Asia.

<i>Globitermes sulphureus</i> Species of Asian termite whose soldiers are known for their potentially suicidal attack.

Globitermes sulphureus is a species of termite that is very common in central and southern Vietnam and also present in other areas of South East Asia, including Cambodia, Thailand, and Peninsular Malaysia. They live in nests made of earth that can be up to 1.5 m tall and can contain tens of thousands of individuals. Between five and 10 per cent of the population are soldier termites which can be recognised by their yellow abdomen and two large, curved mandibles. The termites use autothysis as a defense mechanism.

Colobopsis anderseni, synonym Camponotus anderseni, is a species of mangrove ant found in northern Australia.

<i>Cephalotes texanus</i> Species of ant

Cephalotes texanus is a species of arboreal ant of the genus Cephalotes, characterized by an odd shaped head, and the ability to "parachute" by steering their fall if they drop off of the tree they're on. Giving their name also as gliding ants. The species is native of Texas and of the Mexican states of Nuevo Leon, San Luis Potosí and Tamaulipas. Their larger and flatter legs, a trait common with other members of the genus Cephalotes, gives them their gliding abilities.

<i>Blepharidatta</i> Genus of ants

Blepharidatta is a rare Neotropical genus of ants in the subfamily Myrmicinae. The genus, formed by predatory species whose small colonies nest in soil or leaf-litter, has up to seven species, but most of them are waiting for a formal taxonomic treatment or confirmation.

<i>Novomessor cockerelli</i> Species of ant

Novomessor cockerelli is a species of ant in the subfamily Myrmicinae. It is native to the deserts of the Southwestern United States and Mexico. It lives in large underground colonies in which there is a single queen. The worker ants leave the nest daily to forage for seeds, plant material and dead insects.

<i>Myrmecia regularis</i> Species of ant endemic to Australia

Myrmecia regularis is a species of ant endemic to Australia. A member of the genus Myrmecia in the subfamily Myrmeciinae, it was first described by American entomologist Walter Cecil Crawley in 1925. These ants are medium to large in size, measuring 10 to 20 millimetres, and they are bright brownish-red in colour. Queens and workers share similar morphological features, but they can be distinguished by the noticeable size difference. Males also look similar, but collected specimens are too damaged to be examined properly.

<span class="mw-page-title-main">Ergatoid</span> Wingless reproductive ant or termite

An ergatoid is a permanently wingless reproductive adult ant or termite. The similar but somewhat ambiguous term ergatogyne refers to any intermediate form between workers and standard gynes. Ergatoid queens are distinct from other ergatogyne individuals in that they are morphologically consistent within a species and are always capable of mating, whereas inter caste individuals, another class of ergatogynes, often are not. Ergatoids can exhibit wide morphological differences between species, sometimes appearing almost identical to normal workers and other times being quite distinct from both workers and standard queens. In addition to morphological features, ergatoids among different species can exhibit a wide range of behaviors, with some ergatoids acting only as reproductives and others actively foraging. Ergatoid queens have developed among a large number of ant species, and their presence within colonies can often provide clues on the social structures of colonies and as to how new colonies are founded. Without wings, almost all species of ants that solely produce ergatoid queens establish new colonies by fission.

This is a glossary of terms used in the descriptions of ants.

<i>Colobopsis</i> Genus of ant

Colobopsis is a genus of ant in the subfamily Formicinae. This genus was first described in 1861 by Mayr and contains 95 species. The type species is Colobopsis truncata.

References

  1. 1 2 Wheeler, Diana E.; Hölldobler, Bert (1985). "Cryptic Phragmosis: The Structural Modifications". Psyche: A Journal of Entomology. 92 (4): 337–353. doi: 10.1155/1985/76848 . ISSN   0033-2615.
  2. 1 2 3 4 Brandão, C. R. F.; Diniz, J. L. M.; Silva, P. R.; Albuquerque, N. L.; Silvestre, R. (2001). "The first case of intranidal phragmosis in ants. The ergatoid queen of Blepharidatta conops (Formicidae, Myrmicinae) blocks the entrance of the brood chamber". Insectes Sociaux. 48 (3): 251–258. doi:10.1007/pl00001774. ISSN   0020-1812. S2CID   25923049.
  3. 1 2 3 4 5 6 Jared, C.; Antoniazzi, M. M.; Navas, C. A.; Katchburian, E.; Freymüller, E.; Tambourgi, D. V.; Rodrigues, M. T. (2005-01-01). "Head co-ossification, phragmosis and defence in the casque-headed tree frog Corythomantis greeningi". Journal of Zoology. 265 (1): 1–8. doi:10.1017/s0952836904005953. ISSN   1469-7998. S2CID   59449901.
  4. 1 2 3 4 5 6 Kurosu, U.; Narukawa, J.; Buranapanichpan, S.; Aoki, S. (2006-02-01). "Head-plug defense in a gall aphid". Insectes Sociaux. 53 (1): 86–91. doi:10.1007/s00040-005-0839-4. ISSN   0020-1812. S2CID   2070334.
  5. ↑ Firschein, I. Lester (1951). "Phragmosis and the "Unken Reflex" in a Mexican Hylid Frog, Pternohyla fodiens". Copeia. 1951 (1): 74. doi:10.2307/1438060. JSTOR   1438060.
  6. ↑ Urbani, C. Baroni (1998-08-01). "The number of castes in ants, where major is smaller than minor and queens wear the shield of the soldiers". Insectes Sociaux. 45 (3): 315–333. doi:10.1007/s000400050091. ISSN   0020-1812. S2CID   34121973.
  7. 1 2 3 Fischer, Georg; Azorsa, Frank; Garcia, Francisco Hita; Mikheyev, Alexander; Economo, Evan (2015-05-10). "Two new phragmotic ant species from Africa: morphology and next-generation sequencing solve a caste association problem in the genus Carebara Westwood". ZooKeys (525): 77–105. doi: 10.3897/zookeys.525.6057 . ISSN   1313-2970. PMC   4607851 . PMID   26487817.
  8. ↑
    • Zhu, M.S., Zhang, J.X & Zhang, F. (2006): Rare spiders of the genus Cyclocosmia (Arachnida: Araneae: Ctenizidae) from tropical and subtropical China. The Raffles Bulletin of Zoology54(1): 119-124 PDF (with pictures)
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.