Leptothorax scamni

Complete colonies, solitary queens, and groups of founding queens were collected in a coniferous forest on a south exposed slope below the Abastumani Astrophysical Observatory, Samtskhe-Javakheti region, Georgia (N:41045.4730, E: 042049.0440, elev. appr. 1535 m) in August 2010 and September 2013. Quite unusual for Leptothorax, colonies nested under the bark on the southern side of stems of Caucasian firs (Abies nordmanniana) and Oriental spruce (Picea orientalis) up to 1.6 m above the ground. Many nests were found near old, withered, injured stem areas, where resin had been tapped, and some colonies were completely surrounded by dry resin deposits. Six colonies were also found in rotting logs and tree stumps on the ground, the typical nest site of other species of Leptothorax. (Heinze and Gratiashvili 2015)

Distribution based on Regional Taxon Lists
Palaearctic Region: Armenia, Georgia, Russian Federation, Turkey.

Biology
Heinze and Gratiashvili (2015) - In August 2010 and September 2013 we collected colonies of L. scamni at its type locality in Abastumani, Georgia. In total we found seven solitary queens, two colonies consisting of five and six queens and one or four workers with a few larvae, and 32 larger colonies (5 queenless, 11 with a single queen, 18 with multiple—2 to 13—dealate female sexuals or queens of unknown reproductive status).

Dissections of queens from collected colonies showed colonies were functionally monogynous. Each examined colony contained only a single physogastric queen with maturing oocytes in its ovaries. Other mated or unmated queens had short ovarioles without maturing viable eggs, though some ovaries contained trophic eggs with large yolky droplets. Similar to other functionally monogynous Leptothorax, the contribution of nestmate queens to the brood is, therefore, highly skewed.

In the laboratory, males and young queens of L. scamni showed sexual activity early in the morning and mated without much flight activity.

Our fieldwork supports the earlier impression that L. scamni is rather patchily distributed. Despite intensive search in other areas around Abastumani, we found colonies only on a south-exposed slope in an open spruce forest.

In contrast to other Leptothorax species, which live at the base of pine trees or in rotting branches (e.g., Buschinger 1968a; Seifert 2007), L. scamni nested under the bark of spruce and fir trees and many nests were surrounded by large deposits of dry resin.

Nomenclature

 *  scamni. Leptothorax (Mychothorax) muscorum var. scamni Ruzsky, 1905b: 620, fig. 151 (w.) CAUCASUS. Heinze, Schulz & Radchenko, 1993: 180 (q.). Raised to species: Arnol'di, 1977a: 204.