Leptomyrmex dolichoscapus, Smith, Derek J. & Shattuck, Steve, 2009

Smith, Derek J. & Shattuck, Steve, 2009, Six new, unusually small ants of the genus Leptomyrmex (Hymenoptera: Formicidae), Zootaxa 2142 (1), pp. 57-68 : 61-63

Leptomyrmex dolichoscapus sp. n.

( Figs 7–9 , 19, 20 , 22 )

Types. Holotype worker from Mary Creek site 1, 1000m, 16°33.6’S 145°16.5’E, Queensland, 20 Nov 2005, 12341, Sze Yek, Rainforest , day, hand collect, Steve Williams site CU10A1 ( QMBA: QMBA T143382 ); two paratype workers, same data as holotype ( QMBA: QMBA T143384 , T143385 ).

Diagnosis. Head elongated head (CI less than 79, Fig. 19 ), antennal scape very elongated (SI greater than 220, Fig. 20 ) and extending beyond the vertex of the head by 2/3 their length. Palps very long. Anterior mesonotum with a weak “bump”. Pilosity short adpressed hairs.

Worker description. In full face view vertex of head convex, rounding into sides of head, sides of head weakly rounded, widest at mid-length, eyes placed at mid-length of head capsule. Palps long extending to posterior of head capsule or just beyond. Pronotum above level of promesonotal suture, posterior margin of pronotum rounding sharply to the suture; anterior portion of the mesonotum initially in same plane as pronotum then rounding sharply into descending plane of remainder of mesonotum ( Fig. 8 ) producing a weakly raised anterior mesonotal “bump”. Legs long; hind tibial spurs with reduced barbules, barbules absent from basal ¼. Dark brown in colour.

Measurements. Worker (n = 3) - CI 63–66; EL 0.20–0.22; HL 0.92–0.95; HW 0.58–0.63; MTL 0.98–1.04; SI 230–239; SL 1.37–1.44; WL 1.48–1.64.

Comments. This species is known from only a single locality. It occurs in rainforest and is sympatric with L. garretti from which it is readily distinguished from by its extremely long scapes. Given that L. garretti is also found at lower altitudes in the area it would be interesting to examine samples from along the ranges to determine whether this species is restricted to higher altitudes within in the wet tropics.

Figures

FIGURES 7–12. Leptomyrmex dolichoscapus sp. n. holotype worker. Fig. 7, front of head; Fig. 8, lateral view of body; Fig. 9, dorsal view of body. Leptomyrmex garretti sp. n. holotype worker. Fig. 10, front of head; Fig. 11, lateral view of body; Fig. 12, dorsal view of body.

FIGURES 19–20. Fig. 19, graph of head length versus head width. Fig. 20, graph of scape length versus head width.

FIGURES 21–22. Distribution of material examined during this study. Fig. 21, L. aitchisoni (triangle), L. burwelli (circle) and L. ramorniensis (square). Fig. 22, L. dolichoscapus (circle), L. garretti (triangle) and L. pilosus (square). Note the restricted range of most species, especially the set in Fig. 22, where all species are essentially sympatric.