Leptanillinae

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Leptanillinae
Leptanilla revelierii

Leptanilla revelierii

Systematics
Class : Insects (Insecta)
Order : Hymenoptera (Hymenoptera)
Subordination : Waist Wasps (Apocrita)
Family : Ants (Formicidae)
Subfamily : Leptanillinae
Scientific name
Leptanillinae
Emery , 1910

The Leptanillinae are a small subfamily of ants with distribution in the tropics and the warm temperate zone of the Old World . It comprises 58 species in 6 genera (as of 2014). As far as is known, all species are characterized by an underground way of life. The Leptanillinae are considered to be one of the most original groups of ants still alive.

features

Workers of the Leptanillinae are very small, usually between one and three millimeters in length, and pale in color. You are completely eyeless. The head is elongated and flat. The antennae consist of 12 members, they insert widely separated from each other, mostly near the front edge of the head; their turning point is never covered by frontal praises. The clypeus is sometimes lobed in the middle. The mandibles are elongated and serrated, adapted to predatory diets. Both maxillary and labial palps are single-segmented in the Leptanillini, while more segments (up to four) occur in the Anomalomyrmini. The trunk section (Alitrunk or Mesosoma) is elongated and narrow, with a single visible seam between prothorax and mesothorax, it can be moved against each other on this. The tibia of the middle and hind legs carry a spur. The free abdomen or gaster is connected to the trunk section by two thickened stalk members, called petiolus and postpetiolus, the petiolus is short, not stalked (only in Furcotanilla the postpetiolus is broad, not separated, to the gaster). The guest is short and compact. A functional poison sting is hidden inside.

Queens of the tribe Lepanillini are always wingless with greatly distended abdomen for increased egg production, this will " physogastrisch called". Like the workers, they are eyeless (exception: Leptanilla escheri ), but have ocelles . The free abdomen joins them with only one limb, the petiolus. Queens of the second Anomalomyrmini tribe are known to be winged and have eyes. The queens shear off their wings after the wedding flight.

The larvae have a peculiar body shape with a very small head, narrow trunk and greatly enlarged posterior abdominal segments. Your mandibles are only toothed on the outside (exodont).

male

Leptanilla swani from Australia, male. (Picture April Nobile, Antweb)

Because of their way of life, males and workers of the Leptanillinae are usually never found together. Males are far more numerous than females, mainly occupied by light trap catches. This makes it difficult to match males and females. The curious situation arises that almost all species are known and described either only as males or only as females. For only one species, Leptanilla japonica , a processor gives the males for a species known from females.

Males of the subfamily are darkly colored, they have both wings and large complex eyes protruding from the head contour and three ocelles. The antennae have thirteen segments, one more link than the females.

Biology and way of life

The biology of most species is unknown. From the sparse finds and the morphology, it is generally concluded that there is a completely subterranean way of life, with hunting in the ground. The anatomy of the mouthparts suggests a predatory diet for all species. In the only slightly better researched species, Leptanilla japonica , the nests are in the forest floor, about 10 to 15 centimeters deep. The irregular cavities appear as if they had not been excavated, but had only been occupied by the colonies. Eggs, larvae and pupae lie together in an undivided mass. The queen lays the hundred or so eggs more or less synchronously. The larvae develop from midsummer, around July to November, and overwinter. Only one queen was found in all colonies (monogynous). The number of workers per colony is estimated at around 100 to 200. Inside the nest chamber, animals move on fixed paths that are marked by pheromones . Another species has also identified an alarm pheromone that is released from the mandible gland.

The only prey that workers of Leptanilla japonica colonies transported to the laboratory would accept was small centipedes of the order Geophilomorpha . With a length of 10 to 15 millimeters, the captured animals were considerably larger than the ants. The prey is attacked by several workers with the poison sting until it is paralyzed, and then carried into the nest. Occasionally the entire colony would also move towards the immobilized prey. The larvae are carried to the prey, on which they eat independently. Workers do not carry the larvae with their mandibles, but with the other mouthparts, grasping special processes on their prothorax.

Similar to the species of the subfamily Amblyoponinae , the animals can feed themselves in food shortage situations by piercing the cuticle of their own larvae at preformed, gland-like places and sucking hemolymph . The larvae serve as a kind of food buffer for times of need.

distribution

Leptanillinae live in the tropics and subtropics of the Old World, in Asia, Africa and Europe, with one species also in Australia. In Europe, some species have been found in the Mediterranean region , all of them belonging to the genus Leptanilla , with new species being discovered all the time. In the entire Mediterranean region, including North Africa and the Levant, six species (plus four as yet undescribed) are only given as males and eleven species only as females (as usual, neither sex of any species is known). The greatest variety is known from China.

Details of the subfamily for the Neotropics (South and Central America) refer to species of the subfamily Leptanilloidinae . As we know today, these are not closely related to the Leptanillinae.

Phylogeny, taxonomy, systematics

The subfamily includes two tribes , six genera and 58 species

The workers can be identified with the key from Xu to the genus, the online key from Antwiki based on this can also be used.

The position and relationship of the Leptanillinae is not fully understood. Traditionally, the then only known genus Leptanilla was considered a close relative of the driver ants of the genus Dorylus , with which they have many details in body structure and way of life in common. William Morton Wheeler placed them in their own subfamily Leptanillinae due to numerous peculiarities of the morphology , which has prevailed in research with almost no dissenting opinion.

They belong to the most pristine living ants, the poneroids or poneromorphic clades. In some studies on a molecular (based on the comparison of homologous DNA sequences) and morphological basis, they are either completely isolated or they were identified as the most primitive ants of all, together with all the others as a sister group . This position is only challenged by the Martialinae, with the only known species, Martialis heureka . In the DNA examinations, however, there is concern that the position could be influenced by an artifact known as "long branch attraction". B. due to the higher development speed of particularly strongly deviating sequence in the analysis, so to speak "pushed to the edge". According to morphological characteristics alone, there are relationships to the subfamily Amblyoponinae , which also lives underground .

Individual evidence

  1. ↑ Subfamily: Leptanillinae at AntWeb
  2. ^ A b Zheng-Hui Xu (2012): Furcotanilla, a New Genus of the Ant Subfamily Leptanillinae from China with Descriptions of Two New Species of Protanilla and P. rafflesi Taylor (Hymenoptera: Formicidae). Sociobiology 59: 477-491.
  3. ^ A b Cesare Baroni Urbani (1977): Materiali per una revisione della sottofamiglia Leptanillinae Emery (Hymenoptera: Formicidae). Entomologica Basiliensia 2: 427-488.
  4. ↑ Cesare Baroni Urbani & Maria L. de Andrade (2006): A new Protanilla TAYLOR, 1990 (Hymenoptera: Formicidae: Leptanillinae) from Sri Lanka. Myrmecological News 8: 45-47.
  5. ↑ Ogata, K .; Terayama, M .; Masuko, K. (1995): The ant genus Leptanilla: discovery of the worker-associated male of L. japonica, and a description of a new species from Taiwan (Hymenoptera: Formicidae: Leptanillinae). Systematic Entomology 20: 27-34.
  6. ↑ K. Masuko (1990): Behavior and ecology of the enigmatic ant Leptanilla japonica Baroni Urbani (Hymenoptera, Formicidae, Leptanillinae). Insectes Sociaux 37 (1): 31-57.
  7. ↑ J. Billen, F.Ito, R.Maile, ED Morgan (1998): The Mandibular Gland, Probably the source of the alarm Substance in Leptanilla sp. (Hymenoptera, Formicidae). Science 85: 596-597.
  8. ↑ Antonio Scupola & Rodolfo Ballarin (2009): The genus Leptanilla Emery, 1870 in Sicily (Hymenoptera, Formicidae). Myrmecological News 12: 129-132.
  9. ↑ PS Ward (2007): The ant genus Leptanilloides: discovery of the male and evaluation of phylogenetic relationships based on DNA sequence data, In RB Snelling, BL Fisher, PS Ward (editors): Advances in ant systematics (Hymenoptera: Formicidae): homage to EO Wilson - 50 years of contributions. Memoirs of the American Entomological Institute 80: 637-649.
  10. ↑ leptanillinae in AntCat to Online Catalog of the Ants of the World, by Barry Bolton
  11. ↑ Key to Leptanillinae Genera, from Antwiki
  12. ↑ Philip S. Ward: Phylogeny, classification, and species-level taxonomy of ants (Hymenoptera: Formicidae). In: Zootaxa. 1668, 2007, pp. 549-563. PDF (English)
  13. ↑ 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
  14. ^ Corrie S. Moreau (2009): Inferring ant evolution in the age of molecular data (Hymenoptera: Formicidae). Myrmecological News 12: 201-210.
  15. ^ Roberto A. Keller (2011): A Phylogenetic Analysis of Ant Morphology (Hymenoptera: Formicidae) with Special Reference to the Poneromorph Subfamilies. Bulletin of the American Museum of Natural History, Number 355: 1-90. doi : 10.1206 / 355.1 . Access via BioOne.

Web links

Commons : Leptanillinae  - collection of images, videos and audio files