Formica pisarskii Dlussky, 1964

TYPE LOCALITY. — Songino (24 km SW of Ulan Bator), Mongolia.

TYPE MATERIAL. — Syntypes 1 queen, 10 workers (ZMLSU) (ZIPAS) (MZ No. 3297-3299) [investigated].

GEOGRAPHIC ORIGIN OF THE MATERIAL STUDIED. — The numerically evaluated five nest samples with 17 workers and one queen originate from Songino, Somon Bajandelger, and Gorchi in Mongolia. Total number of specimens seen 25.

DESCRIPTION

Worker

Medium-sized (CL 1322 ± 54, 1200-1384). Head elongated (CL/CW 1.069 ± 0.020, 1.039- 1.109). Rather long scape (SL/CL 1.009 ± 0.020, 0.971-1.043). Whole clypeus from anterior to caudal parts with scattered setae (ClySet 4.47 ± 0.52,4-5). Clypeus lateral of the tentorial pit level without or very few pubescence hairs surpassing the anterior margin by> 10 µm. Lateral semierect setae in the ocellar triangle usually present (OceSet 93%). Eye hairs short or absent (EyeHL 7.2 ± 5.5, 0-19). Pubescence in the occellar triangle very dilute (sqrtPDF 7.11 ± 0.45, 6.47-7.84). Craniad profile of forecoxae with few semierect setae (nCOXA 3.74 ± 1.08, 2-6). Dorsal pronotum always with few standing setae (nPN 7.23 ± 3.30, 4-16). Dorsal crest of petiole with few setae. Lateral metapleuron and ventrolateral propodeum only occasionally with single setae (nMET 0.03 ± 0.12, 0-0.5). Outer edge of the hind tibial flexor side conspicuously hairy (nHTFL 8.06 ± 0.93, 7.0-10.5). Semierect setae on gaster tergites always beginning on the first tergite (TERG 1.0 ± 0.0) and distributed over its whole surface. Pubescence distance on first gaster tergite very large (sqrtPDG 7.76 ±0.43, 7.04-8.84).

Queen

(One paratype queen). Very small (CL 1270, CW 1221, ML 2099). Head long (CL/CW 1.040), scape rather long (SL/CL 0.898). Clypeus from anterior to posterior portions with scattered standing setae (ClySet 4). Clypeus lateral of the tentorial pit level without pubescence hairs surpassing the anterior margin by> 10 µm. Lateral semierect setae in the ocellar triangle present. Eye hairs very short and sparse (EyeHL 7). Pubescence in the occellar triangle extremely dilute (sqrtPDF 7.84). Occipital corners of head with appressed pubescence (OccHD 0.0). Dorsal head brilliantly shining (GLANZ 3.0); whole body very dark and shining, almost without microsculpture. Craniad profile of forecoxae with few setae (nCOXA 2.0). Promesonotum with many standing setae (nPN 14, MnHL 99). Outer edge of the hind tibial flexor side conspicuously hairy (nHTFL 9.0). Semi-erect setae on gaster tergites beginning on the first tergite (TERG 1.00) and not restricted to its caudal margin. Pubescence distance on first gaster tergite extremely large (sqrtPDG 8.11).

TAXONOMIC COMMENTS AND

DIFFERENTIAL DIAGNOSIS

F. pisarskii is a species with a unique character combination. There is no other species in the genus with workers combining strongly developed clypeal and pronotal setae with reduced eye hairs and extremely large frontal and gastral pubescence distance. The queens can only be confused with those of suecica and forsslundi but pisarskii differs from the first by the extremely large PDF and PDG and the elongated head and from the latter by the presence of posterior clypeal setae and the large SL/CW (0.934, in forsslundi 0.770 -0.888).

BIOLOGY AND DISTRIBUTION

The known distribution is limited to Mongolia. Dlussky (1965) mentioned two records from in Central Siberia (Chitinskaya oblast’) and East Siberia (Yakutsk) of which I did not see voucher specimens. As habitats are reported by Pisarski and Dlussky southern slopes of hill tops with sparse grassy vegetation. The nests were constructed either as small mounds of normal Coptoformica type (Dlussky) or below stones without epigaeic structures (Pisarski).