Identification of Tetramorium alpestre, T. caespitum et sp. B, and T. impurum ants by classificatory discriminant analysis of worker morphometrics and a thermal-niche estimate

This routine-identification tool accompanies the following paper:
Steiner, F.M., Seifert, B., & Moder, K. & Schlick-Steiner, B.C. (2010) A multisource solution for a complex problem in biodiversity research: description of the cryptic ant species Tetramorium alpestre sp.n. (Hymenoptera: Formicidae) - Zoologischer Anzeiger 249: 223-254.

For requesting a pdf file of the paper, please send an email to florian.m.steiner (at)

The tool uses nest means of at least three workers to identify
the following ants:
Tetramorium alpestre
Steiner, Schlick-Steiner & Seifert, 2010
T. caespitum (Linnaeus, 1758) et sp. B sensu Schlick-Steiner et al. (2006: Molecular Phylogenetics and Evolution 40: 259-273)
T. impurum
(Foerster, 1850)

    Prior to using the tool, please read the above paper as an introduction to the topic and note the following:

>> T. caespitum and T. sp. B are here treated together as " T. caespitum et sp. B" because of their extreme morphological similarity; we have no new information at hand that would doubt the existence of two biologically separate species but will strive to improve their discrimination in a separate in-depth study

>> correct pre-identification of a sample as belonging to either Tetramorium alpestre, T. caespitum et sp. B or T. impurum is a requisite for successful use of the tool; any Tetramorium sample from north of 44 N, 6 - 14 E, and above 1300 m a.s.l. should according to current knowledge be no other than any of these ants, though

>> definitions of all morphometric characters and the thermal-niche estimate, TAS, are given in the above paper; the character definitions need to be accurately implemented by use of the stereomicroscope, at maximum magnification available

>> for use of the tool, click the "data entry" button below and enter the requested character values in the data entry form

>> exclusively enter nest mean data of at least two but ideally three workers

>> you can either enter a TAS value yourself or, alternatively, leave the TAS field empty and enter values for geographical latitude and longitude (both in international decimal format) and altitude (in metres above sea level); in the latter case, TAS will be estimated upon clicking "identify" and the estimated value will appear in the TAS field

>> click the "identify" button to run the classificatory discriminant analysis; the discriminant analysis is based on the optimal character combination of CL / CW, CS, dCV, FL / CS, ML / CS, MPSP / CS, MW / CS, PENL /CS, PEW / CS, PnHL / CS, PosSPu / CS, PreOc / CS, SLd / CS, TAS

>> probability values for the sample's membership to Tetramorium alpestre, T. caespitum et sp. B, and T. impurum are then returned, the highest value being highlighted

>> the discriminant analysis results in 0% misclassification for the 172 nests used in the above paper; the various validation methods of the discriminant analysis used in the above paper suggest that the error rate for unknown nests could amount to up to 5%, though

>> example data can be viewed and used for exploring the tool by clicking the "example" button

>> the Cyber Identification Engine for identifying all nine species of the Tetramorium caespitum/impurum complex (at is still valid, with T. alpestre being referred to as T. sp. A, but this new tool results in a lower misclassification error for the ants it is designed for



If the applet does not work although JAVA is enabled –  please upgrade your JAVA-version at least to version 6

Should you encounter IT-related problems, please contact Karl Moder (karl.moder (at) but contact Florian Steiner (florian.m.steiner (at) with any other question

Copyright Florian M. Steiner, Birgit C. Schlick-Steiner, Bernhard Seifert & Karl Moder 2009

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