Formica mesasiatica Dlussky, 1964

Seifert, Bernhard, 2000, A taxonomic revision of the ant subgenus Coptoformica Mueller, 1923 (Hymenoptera, Formicidae), Zoosystema 22 (3), pp. 517-568 : 532-533

Formica mesasiatica Dlussky, 1964

TYPE LOCALITY. — Talasskiy Alatau and Zailiyskiy Alatau, Tyanshan.

TYPE MATERIAL. — Paratype ( MZ).

GEOGRAPHIC ORIGIN OF THE MATERIAL STUDIED. — Numerically evaluated were 11 different samples with 18 workers and 8 queens from the Tyanshan mountains of S Kazakhstan (7) and Kyrghystan (19). Total number of specimens seen 70.

DESCRIPTION

Worker

Very large (CL 1468 ± 61, 1359-1582; CW 1414 ± 61, 1321-1535). Head shape as in exsecta (CL/CW 1.038 ± 0.014, 1.002-1.061). Scape long (SL/CL 1.027 ± 0.019, 0.989-1.059). Clypeus also in median and posterior portions with standing setae (ClySet 4.22 ± 0.43,4-5). Lateral semierect setae in the ocellar triangle always present (OceSet 100%). Eye hairs always strongly developed, often hook-shaped (EyeHL 35.7 ± 4.6, 30-47). Pubescence in the occellar triangle always very dense (sqrtPDF 3.99 ± 0.22, 3.58-4.41). Occipital corners in contrast to the exsecta standard with almost appressed pubescence. Craniad profile of forecoxae with few semierect setae (nCOXA 4.58 ± 0.90, 3.0-5.5). Dorsal pronotum and propodeum occasionally, lateral metapleuron and ventrolateral propodeum always with few standing setae (nMET 3.61 ± 1.26, 1.5-6.0). Outer edge of hind tibial flexor side conspicuously hairy (nHTFL 9.50 ± 0.99, 8.0-11.0), with two size classes of setae, and subdecumbent pubescence. Semierect setae on gaster tergites beginning on the first tergite (TERG 1.00 ± 0.0). Pubescence distance on first gaster tergite very low (sqrtPDG 4.43 ± 0.65, 3.72-6.14).

Queen

As large as exsecta (CL 1642 ± 33, 1585-1687; CW 1721 ± 22, 1697-1765; ML 2949 ± 79, 2831-3040). Head broad (CL/CW 0.955 ± 0.023, 0.926-0.985), scape significantly longer than in exsecta (SL/CL 0.994 ± 0.023, 0.957- 1.024). Clypeus also in posterior portions with standing setae. Lateral semierect setae in the ocellar triangle usually present. Eye hairs always long and numerous, often hook-shaped (EyeHL 49.2 ± 6.2, 40-55). Pubescence in the occellar triangle always very dense (sqrtPDF 3.56 ± 0.20, 3.33-3.85). Occipital corners of head with decumbent or subdecumbent hairs (OccHD 38.5 ± 9.3, 31-59); queens with appressed hairs are reported to occur (Dlussky 1967). Brilliance of dorsal head surface low, weakly sculptured surfaces dominate (GLANZ 1.41 ± 0.38, 1.0-2.0). Craniad profile of forecoxae with semierect setae (nCOXA 8.06 ± 1.52, 6.0-11.0). Promesonotum always with standing setae that clearly differ from semierect pubescence (MnHL 195.3 ± 29.2, 152- 233). Outer edge of the hind tibial flexor side conspicuously hairy (nHTFL 9.43 ± 2.87, 6.0- 15.0), with two size classes of setae and subdecumbent pubescence. Semierect setae on gaster tergites always beginning on the first tergite (TERG 1.00 ± 0.00). Pubescence distance on first gaster tergite constantly very low (sqrtPDG 3.56 ± 0.20, 3.33-3.85).

TAXONOMIC COMMENTS AND

DIFFERENTIAL DIAGNOSIS

Formica mesasiatica is so far the only reported Coptoformica species from Middle Asia (Tyanshan and N Pamir). This population seems to be fully isolated from the Palaearctic range of exsecta . The description presented here is based upon investigation of a paratype queen stored in MZ, labelled: “Zailijskij Ala-Tau, verch. r. Almatin, 18.7.58” and the investigation of further 10 samples with workers and queens collected by R. Schultz in the Kazakhian and Kyrghysian Tyanshan. F. mesasiatica shows highly significant (p <0.0001) differences to exsecta in sqrtPDG, sqrtPDH, and nCOXA of queens and workers and in SL/CL of queens ( Tables 6; 8). However, it cannot be completely separated from exsecta by discriminant functions even on the basis of nest sample means. Because of the very peculiar zoogeographic situation mesasiatica is treated here as species. Complete isolation and bottle-necking events could have caused a loss in phenotype diversity.

BIOLOGY AND DISTRIBUTION

The distribution is apparently limited to the mountain areas of the Tyanshan and N Pamir where the species is found on steppe-like or semidry grasslands and woodland clearings between 1300-2700 m (Dlussky 1967; Tarbinsky 1976; Schultz pers. comm.). The highest densities were observed in grasslands with bushes. Monodomous nests as well as polycalic colonies were observed. Nuptial flights are delayed with growing elevation and were observed between June 29 and July 30.