Lasius fallax Wilson


Lasius fallax head view  Lasius fallax, side view

Workers straw yellow to dark yellowish brown. Lasius fallax have small eyes and shorter appendages than all other Navajo Reservation Lasius except for Lasius coloradensis. This species is similar to Lasius fallux but has short 3 segmented maxillary palps, which are longer and six segmented in fallux. The scapes of the workers have a dense standing pubescence, which helps separate this species from Lasius sitiens. The latter has hair on its scapes but they are entirely decumbent.
Beyond the collection records scattered among a number of publications, there is little known about the biology of this species. Wilson (1955): "The Glacier National Park series was taken from a populous colony nesting under a stone in a clearing in a pine-fir forest at about 5000 feet." Allred (1982): "Fifty ants in two collections were taken from under rocks in sagebrush: one in association with grass and one with matchbrush. Eight collections whose recorded Utah habitats were known were in montane forest. One recorded elevation is 9750 ft."
additional biology notes...
United States. Rocky Mountains and Great Basin from Idaho and Montana south to southern Arizona.
Navajo Reservation Records
Samples being processed.
Additional Notes
Gregg (1963) took the collection records of Lasius fallax and inferred its potential habitat affinities: "the ant appears to require cool mountain environments, either forest or grassland. The single record for Colorado, cited by Wilson at Hartsel, would place the insect in high level grassland at about 9000 feet. Certain records indicate localities in coniferous forest, and the magnificent spruce-fir-aspen forest on the Kaibab Plateau in Arizona is, of course, of this general type."

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Original Combination - Lasius fallax - Wilson (1955).

the original species description for Lasius fallax (first page) the original species description for Lasius fallax (second page) the original species description for Lasius fallax (third page)

Holotype. A worker in the Creighton Collection selected from a series collected at Bassets Springs, Uinta Mts., Utah, with associated winged queens and males (W. S. Creighton leg.). Paranidotypes are in the MCZ.
Reported by Wilson (1955)
Type Locality
Bassets Springs, Uinta Mountains, Utah

Allred, D. M. 1982. Ants of Utah. Great Basin Naturalist. 42:415-511.
Gregg, R. E. 1963. The ants of Colorado, with reference to their ecology, taxonomy, and geographic distribution. University of Colorado Press, Boulder.
Wilson, E. O. 1955. A monographic revision of the ant genus Lasius. Bulletin of the Museum of Comparative Zoology at Harvard College. 113:1-201.

A note about these publications. The literature cited here is not meant to be an exhaustive list of papers published about this species.

Page authored by David Lubertazzi and Gary Alpert

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