Ants of the Idaho National Laboratory

William H. Clark and Paul E. Blom

Formica manni  © Alex Wild, myrmecos.net, 2004

Introduction

Ants are a very common, widespread and well known group; possibly the most successful of all the insect groups. They occur practically everywhere in terrestrial habitats and outnumber in individuals most other terrestrial animals.  The habits of ants are often very elaborate, and a great many studies have been made of the behavior.  Ants all belong to the class Insecta of the order Hymenoptera (ants, bees, and wasps).  Bolton (1995) recognized 9,536 valid ant taxa.  Estimates for the total number of living ant species in the world range from 15,000 to 20,000 (Hölldobler & Wilson 1990, Bolton 1994).  Ants are one of the few groups of insects that are universally recognized by their very similar body forms.  But there are a few other insects that strongly resemble and mimic ants, and some of the winged forms of ants resemble wasps from which they are derived. 

Data on species diversity and the ecology of the species are fundamental to our understanding of both natural and disturbed ecosystems.  Despite their real and potential importance, our knowledge of the diversity of soil arthropods is still very incomplete.  The role ants play is pivotal as recognized by Hölldobler & Wilson (1990):  "Ants are everywhere, they run much of the terrestrial world as the premier soil turners, channelers of energy, dominatrices of the insect fauna...".  Ants may form very important high protein food sources for many animals including birds (sage thrashers at INL, Clark & Blom 1992) and horned lizards [Clark & Comanor 1976, Whiting et al. (1993)].  Ants also help recycle nutrients by utilizing carrion as food (Clark & Blom 1991). 

The INL is a U.S. Department of Energy multi-purpose laboratory whose primary mission has been to research nuclear technologies.  In the process of fulfilling this mission, the INL researchers have generated radioactive and hazardous wastes (U.S. Department of Energy 1994).  Much of the waste generated in the past is buried in shallow subsurface pits.  Many invertebrates, including ants, burrow into and nest in the soil.  Little is known concerning the potential roles of ants in the restoration aspects of waste management.

Report Abstract

Many invertebrates, including ants, tunnel and nest in soils. Because of these habits, they are potentially important at the Idaho National Laboratory (INL) where they may tunnel into and disturb buried waste.  Ants are very important components of the desert ecosystem based on their distribution, habitat preferences, food habits, and relative abundance.  For these reasons the ant taxa present at the INL were investigated.  A cursory survey of the ants at the site was published in 1971 which reported 22 species.  A more thorough examination was needed.

Our research in the northeastern portion of the Snake River Plain at the INL from 1986 to 1996 produced thousands of ant collections, of which 1,115 (mostly nest series) are used in this manuscript.  These collections contained 46 species in 19 genera from three subfamilies.  This more than doubles the number of the species previously reported from the INL.  Of the ant species found 18 (39 percent) are considered rare on the site, 12 (26 percent) are present but not common, 11 (24 percent) are common, and only five (11 percent) are found to be abundant.  All but three ant genera known for the state of Idaho can be found at the INL.  Additionally, four species collected during this research are reported from Idaho for the first time:  Liometopum luctuosum, Formica gynocrates, Formica spatulata, and Myrmica sp.  Myrmica sp. is undescribed (new to science).

The goal of this investigation is to provide a more thorough survey of the INL ant fauna for both biodiversity and waste management purposes.  The objectives were:

1. To produce an updated checklist of the INL ants.

2. To summarize thee pertinent published information and literature of the INL ants, and

3. To present keys, distribution maps, illustrations, and ecological information on each taxon.

Pogonomyrmex salinus © UCDC www.antweb.org.

Conclusions

We found a moderately rich ant fauna for the cool desert on the INL, which is predominantly sagebrush steppe.  Including corrections to the taxonomy of species reported from the site, this investigation increased the number of known taxa by 270 percent.  It is difficult to speculate how complete this species enumeration is for the INL since our methodology does not permit use of accumulation curves.  The 46 species on the INL seem to us a very rich fauna given the relatively small size of the INL (890 square miles) and moderately high elevation and latitude.  It is likely the diversity of soils (parent materials) and vegetative communities within the reservation's boundaries may contribute to a greater than expected biodiversity.  Still we expect there may be additional taxa to be found (e.g. Crematogaster, Brachymyrmex). 

There is much to learn concerning the ant fauna (as well as all arthropods) at the INL.  Future directions for research should include:

1. More detailed ecological studies.  Fundamental information for most taxa, such as colony size (individuals per colony) and colony densities over the various communities is needed.

2. Additional collection and ecological studies on the "rare" ants collected (Temnothorax tricarinatus, Stenamma smithi).

3. Relationships with fire.  Fire is a natural event at the INL although the fire regime has been altered by man.  What is the potential role of ant community in the area's fire ecology, especially for community persistence and post-fire recovery?

For More Information or for a copy of the full report, please contact William Clark bclark@albertson.edu or Paul Blom pblom@BioDataManagement.com.  Voucher specimens of the ants used in this study are deposited in the Orma J. Smith Museum of Natural History, Albertson College of Idaho.

References

Bolton, B. 1994, Identification guide to the ant genera of the world.  Harvard University Press, Cambridge, MA.  222pp.

Bolton, B. 1995.  A new general catalogue of the ants of the world.  Harvard University Press, Cambridge, MA. 504 pp.

Clark, W.H., and P.E. Blom.  1991.  Observations of ants (Hymenoptera:  Formicidae: Myrmicinae, Formicinae, Dolichoderinae) utilizing carrion.  The Southwestern Naturalist 36:140-142.

Clark, W.H., and P.E. Blom.  1992.  Sagethrasher, Oreoscoptes montanus (Townsend) predation on a mating swarm of the harverster ant, Pogonomyrmex salinus Olsen.  Journal of the Idaho Academy of Science 28:29-32.

Clark, W.H., and P.L. Comanor.  1976.  The northern desert horned lizard, Phyronosoma platyrhinos platyrhinos, as a predator of the western harvester ant, Pogonomyrmex occidentalis, and a dispersal agent for Eriogonum baileyi.  Journal of the Idaho Academy of Science 12:9-12.

Hölldobler, B. and E.O. Wilson.  1990.  The ants.  Harvard University Press, Cambridge, MA.  732 pp.

U.S. Department of Energy. 1994. 1994 INEEL site-specific plan.  U.S. Department of Energ, Idaho Operations Office, Idaho Falls. 229 pp.

Whiting, J.J., J.R. Dixon, and R.C. Murray.  1993.  Spatial distribution of a populations of Texas horned lizards (Phrynosoma cornutum:  Phrynosomatidae) relative to habitat and prey.  The Southewestern Naturalist 38:150-154.