Temnothorax

Temnothorax
	Temnothorax affinis, Belgium
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Crematogastrini
Genus:	Temnothorax; Mayr, 1861
Type species
	Temnothorax recedens; Nylander, 1856
Diversity
	380 species
Synonyms
	Antillaemyrmex Mann, 1920; Chalepoxenus Menozzi, 1923; Croesomyrmex Mann, 1920; Dichothorax Emery, 1895; Epimyrma Emery, 1915; Icothorax Hamann & Klemm, 1967; Leonomyrma Arnol'di, 1968; Macromischa Roger, 1863; Myrafant Smith, M.R., 1950; Myrmammophilus Menozzi, 1925; Myrmetaerus Soudek, 1925; Myrmoxenus Ruzsky, 1902; Protomognathus Wheeler, W.M., 1905

Temnothorax is a genus of ants in the subfamily Myrmicinae. It contains more than 380 species.^[1]

Biology

The workers of Temnothorax species are generally small (mesosoma length 0.715 mm).^[4] Colonies are typically monogynous, although facultative polygyny has been documented in several species. Colony populations are usually quite small, often with less than 100 workers. However, several studies have found colonies of some species to be widely dispersed with several to many satellite nests. Many species are arboreal, living within hollow stems, old beetle or termite galleries, or in galls. Temnothorax species appear to be trophic generalists, feeding on a wide variety of scavenged items, including the elaiosomes of seeds. None have been documented to be active or aggressive predators.^[4]

Phylogenetics

Recent molecular phylogenetic studies show that the genera Chalepoxenus, Myrmoxenus and Protomognathus are nested within Temnothorax, and that the latter is distinct from the more distantly related genera Formicoxenus, Leptothorax and Harpagoxenus. Species in these 'satellite' genera live as social parasites within the nests of other species of Temnothorax.^[4]

Social behaviors

As Temnothorax colonies are small and easy to maintain in a laboratory environment, they are often used to study social behavior in ants.^[1]Temnothorax have been used to show displays of social structures through communication, colony responsibility, and influence.

Communication among ants had been observed by biologists and is assumed to be entirely influenced through substrate-bound odor cues. However, this previously determined social factor has been disproved among Temnothorax; a study isolating navigational influences during emigration. This report concluded that this species relies on visual cues and odor cues are simply used to mark territory.^[5]

Temnothorax species have been studied to determine the extent of queen control over reproductive decisions of her workers. In one study comparing mixed-species colonies and same-species colonies, queens were not able to completely suppress reproduction of the male workers in mixed-species colonies but could suppress male workers in single-species colonies.^[6]

Size of a Temnothorax colony influences the division of labor among workers. By studying 11 colonies of both large and small population sizes (a small colony to consist of 200 to 400 individuals and a large colony to consist of 500 to 700 individuals), the researchers were able to determine how tasks were divided and the proportion of how many workers were active or inactive in the completion of tasks. Seven different tasks are required during the emigration process from an old nest to a new one: scouting, brood transport, adult transport, collection of food (collection of dead Drosophila flies and collection of honey solution), collection of sand materials for wall building, and the actual task of wall building. The proportion of active workers is usually less than 25% and never more than 50%. The ratio of active and non-active workers remains consistent across colony sizes. Specialization of tasks is also not determined by colony size.^[7]

Selected species

Notes

^ ^a ^b ^c Myrmoxenus (including its junior synonyms Epimyrma and Myrmetaerus) was synonymized under Temnothorax by Ward et al. (2015),^[2] but the change was not accepted by Heinze et al. (2015) due to insufficient available data.^[3] However, Seifert et al. 2016 resynonymyzed the genus into Temnothorax.

References

^ ^a ^b ^c Csősz S, Heinze J, Mikó I (2015-11-04). "Taxonomic Synopsis of the Ponto-Mediterranean Ants of Temnothorax nylanderi Species-Group". PLOS ONE. 10 (11): e0140000. Bibcode:2015PLoSO..1040000C. doi:10.1371/journal.pone.0140000. PMC 4633182. PMID 26536033.
^ Ward PS, Brady SG, Fisher BL, Schultz TR (July 2014). "The evolution of myrmicine ants: phylogeny and biogeography of a hyperdiverse ant clade (Hymenoptera: Formicidae)". Systematic Entomology. 40 (1): 61–81. Bibcode:2015SysEn..40...61W. doi:10.1111/syen.12090. ISSN 1365-3113. S2CID 83986771.
^ Heinze J, Buschinger A, Poettinger T, Suefuji M (2015). "Multiple Convergent Origins of Workerlessness and Inbreeding in the Socially Parasitic Ant Genus Myrmoxenus". PLOS ONE. 10 (7): e0131023. Bibcode:2015PLoSO..1031023H. doi:10.1371/journal.pone.0131023. PMC 4519230. PMID 26221735.
^ ^a ^b ^c Snelling RR, Borowiec ML, Prebus MM (2014). "Studies on California ants: a review of the genus Temnothorax (Hymenoptera, Formicidae)". ZooKeys (372): 27–89. Bibcode:2014ZooK..372...27S. doi:10.3897/zookeys.372.6039. PMC 3909803. PMID 24493957.
^ Bowens SR, Glatt DP, Pratt SC (May 9, 2013). "Visual navigation during colony emigration by the ant Temnothorax curvispinosus [corrected]". PLOS ONE. 8 (5): e64367. Bibcode:2013PLoSO...864367B. doi:10.1371/journal.pone.0064367. PMC 3650068. PMID 23671713.
^ Brunner E, Kroiss J, Trindl A, Heinze J (March 2011). "Queen pheromones in Temnothorax ants: control or honest signal?". BMC Evolutionary Biology. 11 (1): 55. Bibcode:2011BMCEE..11...55B. doi:10.1186/1471-2148-11-55. PMC 3060118. PMID 21356125.
^ Dornhaus A, Holley JA, Franks NR (2009). "Larger colonies do not have more specialized workers in the ant Temnothorax albipennis". Behavioral Ecology. 20 (5): 922–929. doi:10.1093/beheco/arp070.