Time filter

Source Type

Schönau-Berzdorf, Germany

Seifert B.,Senckenberg Museum fur Naturkunde Gorlitz | Galkowski C.,2104 route de Mounic

Application of Numeric Morphology-Based Alpha-Taxonomy (NUMOBAT) demonstrated the existence of three cryptic species within the Westpalaearctic Lasius paralienus species complex: L. paralienus Seifert, 1992, having a wider Euro-pean distribution north to Sweden, L. casevitzi sp. nov., an endemic of Corsica, and Lasius bombycina sp. nov. from south-east Central Europe, the Balkans and Asia Minor. Hierarchical NC-Ward clustering and non-hierarchical NC-k-means clustering of 16 morphological characters resulted in 98.7% identical classifications within 76 examined nest samples of the three species. The classification error in 180 worker individuals was 0% in a linear discriminant analysis (LDA) and 1.3% in a LOOCV-LDA. Differential characters to other species groups and an identification key of the six European members of the Lasius alienus Förster species group are provided. © 2016 Magnolia Press. Source

A supercolonial mound-building wood ant was intentionally introduced from the Italian Alps to Quebec, Canada, in 1971. This species was believed so far to represent Formica lugubris ZETTERSTEDT, 1838. Yet, recent investigations on the distributions of F. lugubris and the closely related species F. paralugubris SEIFERT, 1996 in the Italian Alps showed presence of both species and also that the supercolonial social type is represented here mainly by the latter species. This raised doubts on the species identity of the Canadian ants and prompted a taxonomic re-investigation. Advanced exploratory and hypothesis-driven data analyses of worker phenotype of 152 nest samples of both species from the Alps and of two samples collected from the supercolony in Quebec convincingly confirmed the Canadian introduction to represent F. paralugubris. The Quebec samples were safely allocated to the F. paralugubris cluster in both Nest Centroid (NC)-Ward and NC-K-Means clustering, a nest-centroid based principal component analysis (PCA), and a linear discriminant analysis. The error of exploratory data analyses over all 154 samples varied between 0.6% (NC-KMeans) and 1.9% (NC-Ward, PCA). A new method calculating the size of nest populations of polygynous Formica rufa group ants is introduced, according to which the growth of the Valcartier introduction was estimated from about one million workers in 1971 to 19 million workers in 2005. Data on mating biology, strategy and speed of dispersal, colony structure, and ecological requirements indicate that active spreading of this ant to areas remote from the Valcartier beachhead is unlikely. There is also a low probability of passive dispersal by unintentional anthropogenic transfer of colony fragments. Although supercolonial, F. paralugubris lacks some of the essential properties of invasive tramp ants - its species-specific preadaptations are not comparable with the situation in the imported European Fire Ant Myrmica rubra (LINNAEUS, 1758). A prediction of the role of F. paralugubris in the Nearctic forest ecosystems is presented. The concluded low risk of it becoming a dangerous invasive species does not refute the importance of keeping the situation in Quebec under careful observation. Source

Data on four species of the ant genus Tapinoma FÖRSTER, 1850 are presented. Three of these maintain permanent outdoor populations in Central Europe: the autochthonous T. subboreale sp.n., T. erraticum (LATREILLE, 1798) and T. nigerrimum (NYLANDER, 1856) which is a recently established neozoon in Germany. All three species can be safely separated on the individual level both in the female castes and in males by principal component analysis (PCA) and discriminant analysis (DA) of multiple morphometric characters. As the lectotype of T. ambiguum EMERY, 1925 is heterospecific from a more northern species which had been constantly named T. ambiguum during the last 34 years, it was necessary to describe the latter as T. subboreale sp.n. The earlier synonymy of T. ambiguum with T. madeirense FOREL, 1895 was confirmed on the basis of genital characters. The neotype of T. erraticum was fixed from a sample collected at the type locality. Tapinoma madeirense, known from Madeira and southern France, and T. subboreale sp.n. from Central and North Europe cannot be safely distinguished in the female castes but are clearly heterospecific concluded from male genital morphology. Workers of the four considered species show a strong allometry of some shape characters: Within the average intraspecific body-size range and given in per cent of the mean, the relative depth of posterior head excava-tion, of the metanotal groove and of the clypeal excision grow by 66.3%, 52.1% and 14.2% while relative head length falls by 13.6%. Removal of allometric variance in all shape characters and computation of these data in a PCA and a DA showed that worker morphologies of T. nigerrimum and T. erraticum differed independently from body size and, in conclusion, should also be independent from colony maturity. Source

Schlick-Steiner B.C.,University of Innsbruck | Steiner F.M.,University of Innsbruck | Seifert B.,Senckenberg Museum fur Naturkunde Gorlitz | Stauffer C.,University of Natural Resources and Life Sciences, Vienna | And 2 more authors.
Annual Review of Entomology

Good alpha taxonomy is central to biology. On the basis of a survey of arthropod studies that used multiple disciplines for species delimitation, we evaluated the performance of single disciplines. All included disciplines had a considerable failure rate. Rigor in species delimitation can thus be increased when several disciplines chosen for complementarity are used. We present a flexible procedure and stopping rule for integrative taxonomy that uses the information from different disciplines separately. Disagreement among disciplines over the number and demarcation of species is resolved by elucidating and invoking evolutionary explanations for disagreement. With the identification of further promising study organisms and of new questions for in-depth analysis, evolutionary biology should profit from integrative taxonomy. An important rationale is clarity in researcher bias in the decision-making process. The success of integrative taxonomy will further increase through methodological progress, taxonomic training of evolutionary biologists, and balanced resource allocation. © 2010 by Annual Reviews All rights reserved. Source

Seifert B.,Senckenberg Museum fur Naturkunde Gorlitz
Myrmecological News

The taxonomic status of 32 taxa of the ant genus Bothriomyrmex from Europe, North Africa, Asia Minor, and the Middle East was assessed and commented. Four European species were clearly distinguished by high-performance stereomicroscopy, reproducible numeric recording of 18 phenotypical characters and multivariate analyses: B. meridionalis ROGER, 1863, B. atlantis FOREL, 1894, B. communistus SANTSCHI, 1919 and B. corsicus SANTSCHI, 1923. Type investigation and evaluation of original descriptions established that there is definitely no Palaearctic taxon described before 31 March 1923 which is a senior synonym to any of these four names. Principal component (PCA) and discriminant analyses (DA) of 204 workers and 58 gynes clearly showed the following synonymies (in brackets posterior probabilities of type specimens in discriminant analyses): B. meridionalis var. adriaca SANTSCHI, 1922 (p = 1.000) and B. corsicus ssp. mohelensis NOVÁK, 1941 (p = 1.000) are synonyms of B. communistus SANTSCHI, 1919 (p = 1.000) while B. meridionalis ssp. gibbus SOUDEK, 1924 (p = 0.999), B. corsicus ssp. gallicus EMERY, 1925 (p = 1.000), B. corsicus var. ligurica EMERY, 1925 (p = 1.000), and B. menozzii EMERY, 1925 (p = 1.000) are synonyms of B. corsicus SANTSCHI, 1923 (p = 1.000). The performance of the DA was unexpectedly strong: After reduction to eight morphological characters, any individual of B. communistus and B. corsicus was classified with posterior probabilities of p > 0.960 and the error rate in leave-one-out cross-validation was 0%. Furthermore, no specimen was allocated to a wrong cluster in PCA. Source

Discover hidden collaborations