Tetramorium naganum, Bolton, B., 1979

Bolton, B., 1979, The ant tribe Tetramoriini (Hymenoptera: Formicidae). The genus Tetramorium Mayr in the Malagasy region and in the New World., Bulletin of the British Museum (Natural History) Entomology 38, pp. 129-181 : 136-137

Tetramorium naganum sp. n.

(Fig. 7)

Holotype worker. TL 2.8, HL 0.70, HW 0.66, CI 94, SL 0.48, SI 73, PW 0.48, AL 0.78.

Mandibles smooth with scattered pits, without longitudinal striation. Anterior clypeal margin with a median notch or impression. Frontal carinae moderately well developed, extending back almost to the occiput, but becoming confused with the remaining cephalic sculpture before reaching it. Antennal scrobes broad and shallow, without delimited ventral or posterior margins. In full-face view the occipital margin broadly concave, the sides of the head evenly convex and the head narrower in front of the eyes than behind. Dorsal alitrunk in profile evenly convex, the propodeum armed with a pair of straight narrow spines. Metapleural lobes triangular and acute. Node of petiole high and narrow, shaped as in Fig. 7; in dorsal view subglobular, very slightly broader than long. Dorsum of head irregularly longitudinally rugulose, the rugulae fine and widely separated and the interspaces with distinct granular or punctulate ground-sculpture. Dorsal alitrunk covered with irregular fine rugulae which form a disorganized and very broken reticulum, the spaces between them with feeble ground-sculpture which is weaker than on the head. Petiole, postpetiole and gaster unsculptured. Dorsal surfaces of head, alitrunk, petiole and postpetiole with numerous erect fine long hairs and also with scattered pubescence, also erect or suberect. First gastral tergite with abundant subdecumbent pubescence, but without long hairs such as are obvious on the dorsal alitrunk and fringing the remaining gastral segments. Colour orange-brown.

Paratype workers. TL 2.8 - 2.9, HL 0.68 - 0.70, HW 0.62 - 0.66, CI 90 - 94, SL 0.46 - 0.50, SI 73 - 78, PW 0.47 - 0.50, AL 0.70 - 0.78 (11 measured). As holotype.

Holotype worker, Madagascar: La Mandraka, 1280 m, 8. ii. 1977, leaf litter, mont, forest, AB 41 nest in seed capsule in litter (W. L. & D. E. Brown) (MCZ, Cambridge). Paratypes. 16 workers and 1 dealate female, with same data as holotype (MCZ, Cambridge; BMNH).

Among the species of the schaufussi-group which lack long hairs on the first gastral tergite, naganum is unique in having fine long hairs present on the propodeum, petiole and postpetiole. As in cognatum , pubescence on the first gastral tergite is dense and somewhat elevated, not minute, scattered and appressed as in proximum .