Tatuidris tatusia
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Tatuidris tatusia (Image: Erin Prado, Antweb.org) |
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| Brown & Kempf , 1968 | ||||||||||||
| Scientific name of the species | ||||||||||||
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| Brown & Kempf , 1968 |
Tatuidris tatusia is a ground-living ant species from South and Central America. It is one of only two living ( recent ) species of the subfamily Agroecomyrmecinae. In the English-speaking world it is because of the squat body shape and the hard-armored exoskeleton as "armadillo ant" ( " armadillo called ant"). Thescientific species name is also derivedfrom the Guaraní word tatu for armadillo, which was adopted into modern Brazilian.
features
It is a relatively small species of ants; workers reach a body length of around 3.5 millimeters, although the size is quite variable between different individuals. It is of a uniform brown to reddish brown color with a smooth, shiny, hard sclerotized cuticle . The free abdomen ( gaster ) connects to the trunk section with a two-part stalk ( petiolus and postpetiolus ), petiolus and postpetiolus are relatively short and wide, almost rectangular when viewed from above, the postpetiolus slightly widened backwards towards the gaster.
The head has a very peculiar shape and proportions, which makes the species unmistakable. He is short and broad shield-shaped. The antennas are located far to the side in deeply incised antenna pits and are not visible when viewed from above when they are laid back, their point of deflection is on the underside of the front allobe, i.e. points downwards. They are seven-segment with a compact, two-part club. The small complex eyes (5 to 10 ommatidia ) sit far back, at the rear end of these antenna pits, somewhat variable either on the top or the bottom. Since the seams of the clypeus are also fused, the head appears to be an undifferentiated plate when viewed from the front.
The mandibles are triangular, their edges touch each other in the resting position without overlapping, their chewing bar is slightly wavy, with two short, blunt teeth. On both sides of the inside, near the chewing bar, there is a brush-like hair made up of short, stiff bristles that interlock when the mandibles are closed. The short, wide labrum is slightly incised in the middle. The maxillary palps are one, the labial palps two-part.
The trunk section ( mesosoma or alitrunk ) is short and compact. The seam between the pronotum and mesonotum is immovably fused. The tibia of the middle and hind legs have combed (laterally regularly incised) spurs. The propodeum has no thorns or teeth. The guest has a long, functional, poisonous sting. At the rear edge of the fourth abdominal sternum there is a ridge that can be used to produce sounds through stridulation . The tergite of this segment is enlarged and considerably longer than the sternite , which makes the gaster appear curved downwards.
The queens are similar in shape and proportions to the workers, but a little lighter, more like yellow, in color. The complex eyes are slightly larger and there are also three ocelles . They are fully winged and capable of flying. The males also resemble the workers, but are darker in color. Her head is matt due to a rough, somewhat scaly microsculpture. The workers' characteristic feeler pits are missing, the point where the antennae deflects is visible from above. They too have large complex eyes and three ocelles. The antennae are, unlike the females, twelve-segment.
Way of life
The workers of the species are almost never seen above ground. Their habitat is within the topsoil and the litter of forest floors. To date, only two observations of a nest in the open with live animals have been made, all other evidence of finds is based on soil traps or heat extraction from drilled litter and soil samples. The nests found so far were very small, with few workers and relatively many sex animals (Gynen). The animals observed moved with slow, inconspicuous movements, and the species also seems to be rather nocturnal. Breeding in the laboratory has already failed because the animals spurned all the food offered to them. Nonetheless, all editors agree that it must be a type with, possibly very specialized, predatory diet. Analysis of stable nitrogen - isotope N15, which is in the food chain tend to accumulate, suggest a trophic position even of the fourth Trophieniveaus close, so as predators of another robber.
In most habitats, the species is considered to be very rare, and there are often only a few individuals. However, it is not entirely clear to what extent this is due to the very hidden, cryptic way of life of the species. In an investigated submontane rainforest on the eastern slope of the Ecuadorian Andes , which was considered to be a favorable habitat for the species, a density of about one individual per square meter was calculated from soil samples.
habitat
Tatuidris lives in Central and South America, north to central Mexico, south to the Amazonian lowlands of Peru. According to the findings so far, it prefers middle mountain areas, from around 800 to 1200 meters above sea level. There are also finds from the tropical lowlands, east to French Guiana and Brazil. The finds from Guyana had been described as a separate species Tatuidris kapasi , but this was synonymous with Tatuidris tatusia in the genus revision by David Donoso .
Phylogeny and Systematics
According to David Donovan's study, the species is extremely variable both genetically and morphologically. In particular, the hair is extremely varied. Four basic types (designated as "A" to "D") could be distinguished according to the hair pattern on the top of the head. However, since these did not match the groups formed on the basis of the DNA sequence analysis, they were not described taxonomically. The individuals described as Tatuidris kapasi lie within the range of variation, so although they can be clearly distinguished from Brown's type material, they were synonymous under the same species name. It is in Tatuidris tatusia either an extremely variable type whose extremes are interconnected by intermediate forms, or a complex previously distinguishable crypto species .
The species was included in the subfamily Myrmicinae when it was first described . The position of the species group as a very basal branch of the Myrmicinae can be justified according to morphological criteria and was maintained by some taxonomists at least until recently. In 2003, the influential myrmecologist and systematist Barry Bolton elevated the species and its (few) relatives, previously regarded as a tribe , to the new subfamily Agroecomyrmecinae.
In addition to our species, the Agroecomyrmecinae initially include three fossil species, the Agroecomyrmex duisburgi, described from the Baltic amber, and two species of the genus Eulithomyrmex from the Eocene limestone of Florissant, Colorado, USA. In the meantime, the African Ankylomyrma coronacantha has been included in the subfamily as a fifth species. According to phylogenomic analyzes, based on the comparison of homologous DNA sequences, in which the sequence of Tatuidris was included, the Agroecomyrmecinae are not closely related to the Myrmicinae, but belong to the original, "poneromorphic" or "poneroids" ants.
Individual evidence
- ^ A b William L. Brown Jr & Walter W. Kempf (1968): Tatuidris, a remarkable new genus of Formicidae (Hymenoptera). Psyche Vol.74, No.3: 183-190.
- ↑ a b c d e f David A. Donoso (2012): Additions to the taxonomy of the armadillo ants (Hymenoptera, Formicidae, Tatuidris). Zootaxa 3503: 61-81.
- ↑ a b c Justine Jacquemin, Thibaut Delsinne, Mark Maraun, Maurice Leponce (2014): Trophic Ecology of the Armadillo Ant, Tatuidris tatusia, Assessed by Stable Isotopes and Behavioral Observations. Journal of Insect Science, 14 (108): 1-12. doi : 10.1673 / 031.014.108
- ↑ Sebastien Lacau, Sarah Groc, Alain Dejean, Muriel L. de Oliveira, Jacques HC Delabie (2012): Tatuidris kapasi sp. nov .: A New Armadillo Ant from French Guiana (Formicidae: Agroecomyrmecinae). Psyche Volume 2012, Article ID 926089, 6 pages doi : 10.1155 / 2012/926089
- ↑ GM Dlussky & AP Rasnitsyn (2009): Ants (Insecta: Vespida: Formicidae) in the Upper Eocene amber of Central and Eastern Europe. Paleontological Journal Vol. 43, No. 9: 1024-1042.
- ↑ Barry Bolton (2003): Synopsis and classification of Formicidae. Memoirs of the American Entomological Institute Vol 71, 370 pp.
- ↑ Barry Bolton (1981): A revision of six minor genera of Myrmicinae (Hymenoptera, Formicidae) in the Ethiopian zoogeographical region. Bulletin of the British Museum of Natural History (Entomology) 43 (4): 245-307.
- ↑ Philip S. Ward, Sean G. Brady, Brian L. Fisher, Ted R. Schultz (2014): The evolution of myrmicine ants: phylogeny and biogeography of a hyperdiverse ant clade (Hymenoptera: Formicidae). Systematic Entomology (online before print) doi : 10.1111 / syen.12090
- ↑ CS Moreau, CD Bell, R. Vila, SB Archibald, NE Pierce (2006): Phylogeny of the ants: diversification in the age of angiosperms. Science 312: 101-104. doi : 10.1126 / science.1124891
- ↑ Philip S. Ward (2007): Phylogeny, classification, and species-level taxonomy of ants (Hymenoptera: Formicidae). Zootaxa 1668: 549-563. PDF
