Tetramorium aspersum

Some sparse collection information shows this ant occurs in forest habitats and has been collected from epiphyte roots and on vegetation.

Identification
Bolton (1977) - This is a widespread and very variable species. Of the material which I have examined no two populations are exactly alike but all show variation in eye diameter, intensity and density of sculpture, size and degree of hairiness. Considerable variation may be met in nest-series as one sample from Dumaguete (Philippines) collected by J. W. Chapman on 4.ix.1927 shows a CI range of 87-93 and an SI range of 109-123, which virtually spans the known range for the species as a whole.

There is an obvious temptation to separate the more extreme forms of this species and treat them as separate entities but I am by no means convinced (with the rather limited number of samples available) that any lines other than arbitrary ones can be drawn to subdivide this mass at present. Of course, when more collections have been made one or more siblings may possibly be separated, but I feel that this will not be accomplished for some time yet.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Indonesia, New Guinea, Philippines, Solomon Islands.

Nomenclature

 *  aspersum. Myrmica aspersa Smith, F. 1865: 72 (w.) INDONESIA (Morotai I.). Combination in Xiphomyrmex: Donisthorpe, 1932c: 473; in Tetramorium: Bolton, 1977: 86. Senior synonym of bismarckii, willowsi: Bolton, 1977: 86.
 * bismarckii. Tetramorium (Xiphomyrmex) bismarckii Forel, 1901b: 11 (w.) NEW GUINEA (Bismarck Archipelago). Junior synonym of aspersum: Bolton, 1977: 86.
 * willowsi. Xiphomyrmex costatus subsp. willowsi Wheeler, W.M. 1934a: 177 (w.) SOLOMON IS. Junior synonym of aspersum: Bolton, 1977: 86.

Worker
Bolton (1977) - TL 3.6-4.4, HL 0.86-1.00, HW 0.76-0.90, CI 82-93, SL 0.86-1.10, SI 109-126, PW 0.60-0.74, AL 1.06-1.20 (31 measured).

Mandibles feebly and superficially longitudinally striate. Antennal scapes very long. SI always > 105, projecting well beyond the occipital margin when laid back in full-face view. Scrobes reduced to a narrow impression bounded above by the extensions of the frontal carinae, petering out posteriorly, and with a series of transverse rugae running across the impression. Metapleural lobes long and dentiform, acute. Petiole in profile a high, narrow node, the tergal portion much higher than long. Postpetiole generally more massive than petiole. Dorsum and sides of head covered with a loose, open rugoreticulum except anteriorly between the frontal carinae where the cross-meshes are feeble or absent and the sculpture is predominantly or completely of longitudinal rugae. Density and intensity of cephalic sculpture vary amongst different populations but are always distinctive. Dorsal alitrunk with a rugoreticulum but the pedicel segments and gaster unsculptured, completely smooth. All dorsal surfaces of body and head with erect or suberect hairs. Colour uniform yellow-brown to reddish brown.

Type Material
Bolton (1977) - Syntype workers, Indonesia: Morty (= Morotai) Is (A. R. Wallace) [examined].