Liometopum luctuosum

Liometopum luctuosum
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Dolichoderinae
Genus:	Liometopum
Species:	L. luctuosum
Binomial name
	Liometopum luctuosum; Wheeler, W.M., 1905 Specimen labels

This species has been considered a subspecies of Liometopum occidentale, but occurs at higher elevations (usually above 2000 meters). The distributions of the two are parapatric or sympatric in a number of areas, especially the mountains of southern California, with no apparent hybridization. (Mackay and Mackay 2002)

Identification

Polymorphic, concolorous dark brown workers. The body is covered with a dense pubescence, a feature that partially explains the common name for ants in this genus - "velvety tree ants." It is possible to separate Liometopum luctuosum from Liometopum apiculatum by the presence of a metanotal suture that breaks up the dorsal mesosomal outline, the short and relatively sparse standing hairs on the top of the pronotum and their dark coloration. The largest workers of Liometopum apiculatum are distinctively larger than the largest sized luctuosum workers.

Keys including this Species

Key to US Liometopum species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: 49.9° to 19.294409°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Nearctic Region: United States (type locality).
Neotropical Region: Mexico.
Range United States and Mexico. Washington state, south to Central Mexico, east to western Texas.

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Biology

Liometopum luctuosum nest under rocks, decaying logs and at the base of large trees. Colonies can be large and their abundant workforce can be quite noticeable due to their long foraging trails and constant activity. Foraging can be persistent throughout the day and night. This species is closely related and shares much in common with its co-occuring congener Liometopum apiculatum. Liometopum luctuosum is usually found at higher elevations (> 2000 m) but does occur in suitable habitat in lower elevation sites.

This species can be found in habitats with sagebrush, oaks, Ponderosa pine, Douglas fir, and in riparian habitats found at higher elevations. Liometopum luctuosum is an aggressive ant and the excitable workers will stream out of the nest, emitting a strong odor, and quickly swarm upon anything located near the nest entrance when a colony is disturbed.

They can form long and very busy trails that are used for foraging or to connect segments of their polydomous nest. Established trail routes can persist for many years (Shapley 1920). Foraging columns can also be located under the ground and litter, surfacing underneath ground level objects such as rocks and downed wood. Colonies are rarely investigated because both finding and excavating a nest can be difficult. Foraging trails often disappear into inaccessible holes (e.g. around the roots at the base of a tree) or into a cavity that is more a satellite location where some workers may congregate rather than a part of the nest. Workers disappearing under a rock that can be flipped over, for example, are typically found to be using the covering object to make their way into one of their underground trails. In some cases these cavities will contain numerous workers, but no brood, and digging reveals there are no additional nest chambers nearby. When the main section of the nest is found, or suspected to be located, it may be situated in a tree bole or under a large rock.

Both their odor and aggressive nature make them a potential nuisance when they do, albeit relatively rarely, settle in or around human structures. Reproductive flights occur in June and July, at least in the southwest.

Mackay and Mackay (2002) noted for New Mexico: Habitat Sagebrush, pinyon pine, oak forests, ponderosa pine-riparian, Douglas fir, riparian habitats at high elevations, mixed canyon forests, widely distributed in New Mexico. Biology Nests are found in living or dead tree trunks or in the soil under stones or logs. Soils are usually rocky loam, but it also occurs in sandy areas. These ants are very aggressive. Flights occurred during June and July; sexuals can be collected at blacklights or in bodies of water the day after flights. We have not found myrmecophiles in nests.

Association with Other Organisms

Explore: Show all Associate data or Search these data. See also a list of all data tables or learn how data is managed.

This species is a mutualist for the aphid Rhopalosiphum nymphaeae (a trophobiont) (Jones, 1927; Saddiqui et al., 2019).

Flight Period

		X
Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec

Source: antkeeping.info.

Check details at Worldwide Ant Nuptial Flights Data, AntNupTracker and AntKeeping.
Explore: Show all Flight Month data or Search these data. See also a list of all data tables or learn how data is managed.

Castes

Worker


Paralectotype of Liometopum luctousom. Worker. .	Owned by Museum of Comparative Zoology.


Worker. .	Owned by Museum of Comparative Zoology.


Worker. .	Owned by Museum of Comparative Zoology.

Images from AntWeb


Worker. Specimen code casent0102759. Photographer April Nobile, uploaded by California Academy of Sciences.	Owned by CAS, San Francisco, CA, USA.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

luctuosum. Liometopum apiculatum subsp. luctuosum Wheeler, W.M. 1905e: 325 (w.) U.S.A. Forel, 1914c: 619 (m.); Del Toro, et al. 2009: 321 (q.). Subspecies of occidentale: Creighton, 1950a: 339. Raised to species: Wheeler, G.C. & Wheeler, J. 1986g: 55; Mackay, Lowrie, et al. 1988: 102.

Description

References

References based on Global Ant Biodiversity Informatics

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Cole A. C., Jr. 1942. The ants of Utah. American Midland Naturalist 28: 358-388.
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Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
Del Toro I., J. A. Pacheco, W. P. MacKay. 2009. Revision of the ant genus Liometopum (Hymenoptera: Formicidae). Sociobiology 53: 299-369.
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Longino, J.T. 2010. Personal Communication. Longino Collection Database
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Mackay, W., D. Lowrie, A. Fisher, E. Mackay, F. Barnes and D. Lowrie. 1988. The ants of Los Alamos County, New Mexico (Hymenoptera: Formicidae). pages 79-131 in J.C. Trager, editor, Advances in Myrmecololgy.
Mallis A. 1941. A list of the ants of California with notes on their habits and distribution. Bulletin of the Southern California Academy of Sciences 40: 61-100.
Navarrete-Heredia J. L., M. Vasquez-Bolano, and G. A. Quiroz-Rocha. 2007. New mexican distributional data on the Sceptobiini-Liometopum association (Coleoptera: Staphylinidae, Aleocharinae-Hymenoptera: Formicidae, Dolichoderinae). Sociobiology 49(3): 221-229.
Reddell J. R., and J. C. Cokendolpher. 2001. Ants (Hymenoptera: Formicidae) from caves of Belize, Mexico, and California and Texas (U.S.A.) Texas. Texas Memorial Museum Speleological Monographs 5: 129-154.
Rees D. M., and A. W. Grundmann. 1940. A preliminary list of the ants of Utah. Bulletin of the University of Utah, 31(5): 1-12.
Shattuck S. O. 1994. Taxonomic catalog of the ant subfamilies Aneuretinae and Dolichoderinae (Hymenoptera: Formicidae). University of California Publications in Entomology 112: i-xix, 1-241.
Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133
Wheeler G. C., and J. Wheeler. 1986. The ants of Nevada. Los Angeles: Natural History Museum of Los Angeles County, vii + 138 pp.
Wheeler, G.C. and J. Wheeler. 1978. Mountain ants of Nevada. Great Basin Naturalist 35(4):379-396
Wheeler, G.C. and J. Wheeler. 1985. A checklist of Texas ants. Prairie Naturalist 17:49-64.