''Lenomyrmex'' is a

Neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In bioge ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

ant 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 ...

in the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

Myrmicinae Myrmicinae is a subfamily of ants, with about 140 extant genera; their distribution is cosmopolitan. The pupae lack cocoons. Some species retain a functional sting. The petioles of Myrmicinae consist of two nodes. The nests are permanent and ...

Species

* '' Lenomyrmex colwelli'' Longino, 2006 * '' Lenomyrmex costatus'' Fernández & Palacio, 1999 * '' Lenomyrmex foveolatus'' Fernández & Palacio, 1999 * '' Lenomyrmex hoelldobleri'' * '' Lenomyrmex inusitatus'' (Fernández, 2001) * '' Lenomyrmex mandibularis'' Fernández & Palacio, 1999 * '' Lenomyrmex wardi'' Fernández & Palacio, 1999

Distribution

''Lenomyrmex'' includes six rarely collected species from

Costa Rica Costa Rica (, ; ; literally "Rich Coast"), officially the Republic of Costa Rica ( es, República de Costa Rica), is a country in the Central American region of North America, bordered by Nicaragua to the north, the Caribbean Sea to the no ...

Ecuador Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ''Eku ...

. Species have been collected from elevations close to sea level to 1800 m but seem to be mainly restricted to mid-elevations, that is, 1100–1500 m.

Description

The genus is characterized by elongate

mandibles In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...

bearing a series of minute peg-like denticles that arise behind the masticatory margin, by frontal lobes that are poorly expanded laterally, by large and deep antennal fossae, and by pedunculate petiole, with a poorly defined node. Among ''Lenomyrmex'' species, the queen caste has been described only for ''L. mandibularis'', ''L. wardi'' and '' L. inusitatus''.

Taxonomy

The fact that ''Lenomyrmex'' possesses both primitive (e.g., promesonotal suture well developed) and derived (e.g., specialized

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

of the mandibles) characters makes ascertaining its correct

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

position challenging. The genus was tentatively placed in its own tribe, Lenomyrmecini, but its position within the Myrmicinae remained to be determined. Preliminary results of a phylogenetic analysis indicated that ''Lenomyrmex'' fell within a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

of predominantly

New World The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. 3 ...

ants that includes the tribes Attini,

Cephalotini Fungus-growing ants (tribe Attini) comprise all the known fungus-growing ant species participating in ant–fungus mutualism. They are known for cutting grasses and leaves, carrying them to their colonies' nests, and using them to grow fungus on ...

, Dacetini, and the genus ''

Pheidole ''Pheidole'' is a genus of ants that belongs to the ant subfamily Myrmicinae. The genus is widespread and ecologically dominant. It probably includes more than 1000 species. The genus first evolved in the Americas, eventually spreading across th ...

''. The genus was finally placed in Attini, when Ward ''et al.'' (2014) synonymized Lenomyrmecini under Attini.

Biology

The unusual morphology of the mandibles suggests that ''Lenomyrmex'' is a specialist predator on an unknown prey. This habit is possibly linked to its apparent rarity and restricted elevational distribution. The degree of queen-worker dimorphism is weak, suggesting small colony sizes and absence of claustral independent colony foundation. In a study, a thorough inspection of the dead wood lying on the ground and of soil samples failed to uncover any nest of ''L. inusitatus''. This and the fact that both workers and

dealate Alate (Latin ''ālātus'', from ''āla'' (“wing”)) is an adjective and noun used in entomology and botany to refer to something that has wings or winglike structures. In entomology In entomology, "alate" usually refers to the winged form o ...

queens have been extracted from the

leaf litter Plant litter (also leaf litter, tree litter, soil litter, litterfall or duff) is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that have fallen to the ground. This detritus or dead organic material and its constituent ...

(

Winkler method The Winkler test is used to determine the concentration of dissolved oxygen in water samples. Dissolved oxygen (D.O.) is widely used in water quality studies and routine operation of water reclamation facilities to analyze its level of oxygen satura ...

) may indicate that this species nests and forages in the leaf litter.

References

* *

External links

* {{Taxonbar, from=Q4042767 Myrmicinae Ant genera Hymenoptera of South America Hymenoptera of North America