Ants and Ant Guests at the INL Site (2013)

Studies of Ants and Ant Guests at the Idaho National Laboratory Site (2013)


Investigators and Affiliations

  • William H. Clark, Orma J. Smith Museum of Natural History, The College of Idaho, Caldwell, Idaho 83605

Funding Sources

  • Funding is by the principal investigator with some assistance and collaboration with the Orma J. Smith Museum of Natural History.


Clark and Blom (2007) reported the first comprehensive annotated checklist of ants at the INL Site. This publication gives a starting point for additional research relating to ants, their natural history and ecology, and ant guests at INL Site. Ant guests (myrmecophiles) are organisms that live in close association with ants. These are generally mutualistic associations, but may also be commensal or parasitic. Much research remains to be done to better the understanding between ants and their guests.


Immediate objectives are to locate living larvae of the ant guest beetle (Philolithus elata) (Coleoptera: Tenebrionidae) within nests of the harvester ant (Pogonomyrmex salinus) (Hymenoptera: Formicidae). These beetles have been documented from the harvester ant nests here in the past by Clark and Blom (unpublished data), but the larvae have not been previously described. Fresh larvae are needed for scanning electron microscopy (SEM) to provide for a proper description of these organisms. The overall objective will be to document the interaction of this beetle with the ants.

Other observations on additional ant guests will be made as they are encountered. Information relating to the ants of INL Site will be documented as possible. .

Accomplishments through 2013:

During the fall of 2011, 100 nests of the harvester ant (Pogonomyrmex salinus) were selected and marked along Road T-17 near Circular Butte. These nests were then surveyed by INL archaeologists for cultural resources and approval was given for excavation of nests as needed. A total of 10 percent of the nests were excavated during late 2011 and no Philolithus elata were found. Additional nests were excavated during the fall of 2012 and again no Philolithus elata were found. We surveyed 41 nests during July 2013 and found Philolithus elata larvae in six of the nests and pupae in two of the nests.

Accomplishments through 2013:
One ant guest taxa, a desert beetle (Coleoptera: Tenebrionidae: Philolithus elata) (Figure 3a and 3b) was collected in Pogonomyrmex salinus nests and is the subject of study and description (Clark, et al. in prep.). An undescribed species of Jerusalem cricket (Orthoptera: Stenopelmatidae, Stenopelmatus sp.) (Figure 4) was found at the INL Site. The Stenopelmatus was found in the ant nests during previous field work. A series of live individuals including both males and females were needed for a proper species description. We collected 20 live specimens in July 2013. In addition, one specimen was found in one of the excavated ant nests. They have been shipped to the specialist in the group for rearing and description. Both taxa will require more study during future visits to the INL Site. We have now taken preliminary photographs with light and SEM. The results will be published in Clark et al. (in prep).

Figure 10-3a

Figure 10-3b

Figure 10-4

In addition, we are working on a publication relating to past research at the site involving cicadas and Pogonomyrmex salinus nests (Blom and Clark, in prep.)

Plans for Continuation:
Field research will continue into the foreseeable future.

Publications, Theses, Reports:
Two draft manuscripts are being prepared, so far, for this project:

  • Blom, P. E., and W. H. Clark. In Prep. Observations of cicada nymphs, Okanagana annulata Davis (Homoptera: Cicadidae) and the harvester ant Pogonomyrmex salinus Olsen (Hymenoptera: Formicidae) in southeastern Idaho. Manuscript being prepared for the Western North American Naturalist.
  • Clark, W. H., P. E. Blom, and P. J. Johnson. In Prep. Philolithus elata LeConte associated with Pogonomyrmex salinus Olsen nest soils in southeastern Idaho (Coleoptera, Tenebrionidae, Asidinae; Hymenoptera, Formicidae, Myrmicinae). Manuscript being prepared for the Coleopterists Bulletin.

Mary Clark assisted with the field work. Paul E. Blom has assisted with data analysis and detailed photographs of the immature beetles. Oregon Department of Agriculture assisted with the SEM.

Clark, W.H., and P.E. Blom. 2007. Ants of the Idaho National Laboratory. Sociobiology 49(2):1-117.