The ants (Insecta: Hymenoptera: Formicidae) of the Socotra Archipelago Author Collingwood, C. A., Pohl, F., Güsten, R., Wranik, W., van Harten, A. text Fauna of Arabia 2004 20 473 495 journal article 21117 0.5281/zenodo.12560 Tetramorium caldarium (Roger, 1857) Fig. 9 Tetrogmus caldarius Roger, 1857 . - Berl. Entomol. Z. 1: 12. (Poland). Specimens examined: Yemen , Socotra Island : 1 ☿ , Wadi Daneghan , 12°37N 54°04'E , 90 m , 21-22.X.2000 , H. Pohl , HLMD-Hym-2073 ; 4 ☿☿ , 1 9 , Coeeh , 12°32'N 54°10'E , 240 m , 23.X.2000 , A. van Harten , HLMD-Hym-2074 , NHCY ; 1 ☿ , Coeeh , 12°32'N 54°10'E , 240 m , 23.X.2000 , H. Pohl , NHCY ; 1 ☿ , Nojid , Farmihin , Steroh, wadi , 12°24'N 54°09'E , 24.X.2000 , A. van Harten , HLMD-Hym-2075 ; 7 ☿☿ , Wadi Daneghan , 12°37'N 54°04'E , 90 m , pitfall traps , 28-30.X.2000 , A. van Harten & H. Pohl , HLMD-Hym-2076 , NHCY , CCC ; 1 ☿ , Hadibo and immediate surroundings , 12°37'N 54°01'E , 01.XI.2000 , A. van Harten , HLMD-Hym-2077 . Remarks: Tetramorium caldarium is generally considered a less common, though also widely recorded, tramp species than its close relative T. simillimum . The picture of their distribution is somewhat unclear, the two long having been considered synonyms. In contrast to T. simillimum , the frontal carinae are feebly developed and the antennal scrobes virtually absent in T. caldarium . The Socotran examples belong to a rarer variant ( "transformant" ) which has the frontal carinae separated by less than half the head width behind the eyes. This form may constitute a separate species and could originate from eastern Africa (Bolton 1980), casting some doubt whether it has been transferred artificially to Socotra. No records of T. caldarium from the Arabian Peninsula have been brought forth.