Studies of Ants and Ant Guests at the INL Site

Studies of Ants and Ant Guests at the INL Site (2015)

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Investigators and Affiliations

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

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 the 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 and pupae of the ant guest beetle, Philolithus elatus (LeConte; Coleoptera: Tenebrionidae), within nests of the harvester ant, Pogonomyrmex salinus (Olsen; Hymenoptera: Formicidae). These beetles have been documented from the harvester ant nests here in the past by Clark and Blom (unpublished data), but the immature stages (larvae and pupae) have not been previously described. More observations of adult female beetles ovipositing on the ant nests are also needed. 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 the INL Site will be documented in scientific publications, as possible.

Accomplishments through 2015:

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 elatus were found. Additional nests were excavated during the fall of 2012, and again no Philolithus elatus were found. We surveyed 41 nests during July 2013 and found Philolithus elatus larvae in six of the nests and pupae in two of the nests. During the fall of 2014, we examined more nests in the Circular Butte area and collected additional larvae and pupae, which were preserved for study and photography. During 2015, the SEM work was completed for Philolithus elatus immature stages (larvae and pupae). Additional field work was conducted during 2015 at the Circular Butte Site (Figures 10-6 and 10-7). This field work involved searching for female beetles that might interact with the ant nests and other natural history observations. Figure 10-6
Figure 10-7


One ant guest taxa, a desert beetle (Coleoptera: Tenebrionidae, Philolithus elatus) was collected in Pogonomyrmex salinus nests and is the subject of study and description (Clark et al. in prep). We have now taken photographs with light and SEM, and we have observed a Philolithus elatus female ovipositing on a Pogonomyrmex salinus nest. The results will be published in Clark et al. (in prep) and have been presented in Clark et al. (2015). We are also working on a publication relating to past research at the site involving cicadas and Pogonomyrmex salinus nests (Blom and Clark, in prep). In addition, during 2015, we made field observations of spider predation on Pogonomyrmex salinus, and this turns out to be a different spider species as predator of the ant from what we have previously reported for the site (Clark and Blom 1992). An undescribed species of Jerusalem cricket (Orthoptera: Stenopelmatidae, Stenopelmatus sp.) has been 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, and additional specimens were collected during September 2014. 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.

Plans for Continuation:

Field research will continue into the foreseeable future.

Publications, Theses, Reports:

Three 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, P. J. Johnson, and A.D. Smith, In Prep, Philolithus elatus (LeConte) associated with Pogonomyrmex salinus Olsen nest soils in southeastern Idaho (Coleoptera, Tenebrionidae, Asidinae; Hymenoptera, Formicidae, Myrmicinae), Manuscript being prepared for the Coleopterists Bulletin.
  • Clark, W. H., P. E. Blom, and P. J. Johnson, 2015, Philolithus elatus (LeConte) associated with Pogonomyrmex salinus Olsen nest soils in southeastern Idaho.
  • Poster for the Idaho Academy of Science and Engineering Annual Meeting, Boise, Idaho. (Stenopelmatus sp). Found Near Pogonomyrmex Salinus Nests. Near Circular Butte, July 2013.

Acknowledgments 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. Roger Blew provided field access and other logistical assistance.


  • Clark, W. H., and P. E. Blom, 1992, Notes on spider (Theridiidae, Salticidae) predation of the harvester ant, Pogonomyrmex salinus Olsen (Hymenoptera: Formicidae: Myrmicinae), and a possible parasitoid fly (Chloropidae), Great Basin Naturalist 52:385-386.
  • Clark, W. H., and P. E. Blom, 2007, Ants of the Idaho National Laboratory. Sociobiology 49(2):1-117, References for Section 10.1.