Leptomyrmex pilosus, 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 : 63-64

Leptomyrmex pilosus sp. n.

( Figs 13–15 , 19, 20 , 22 )

Types. Holotype worker from 3.0 km W of Cape Tribulation (Site 6), 16°05’S 145°27’E, Queensland, 500m, 5–9 Jan. 1983, G.B.Monteith, rainforest, baited pitfall trap ( ANIC: ANIC32-023631 ); four paratype workers, same data as holotype (2 each in AMSA, ANIC).

Diagnosis. Palps elongated, extending well beyond the posterior margin of the head capsule. Antennal scapes elongated (SI greater than 170, Fig. 20 ) and extending beyond the vertex of the head by about half their length. Distinctive abundant pilosity consisting of shorter adpressed and longer decumbent hairs.

Worker description. Vertex of head weakly convex to flat, corners rounded, sides of the head almost straight, head widest at mid-length. Scape relatively short, surpassing the vertex by about half its length. Palps long, extending to near the posterior of the head capsule. Medial hypostoma distinctly notched. Anterior mesonotum without a raised anterior region. Legs long. Hind tibial spur with reduced barbules, absent from basal 1/5th. Scale present, ridged and with a distinct angle dorsally, in profile bluntly angular, weakly inclined anteriorly, anterior and posterior faces of the scale approximately equal in length. Abundant relatively long appressed yellowish pubescence on mesosoma and gaster, pubescence short adpressed and long decumbent on head and antennal scapes.

Measurements. Worker (n = 7) - CI 78–80; EL 0.20–0.23; HL 0.91–0.98; HW 0.72–0.77; MTL 0.93–1.04; SI 171–175; SL 1.25–1.32; WL 1.43–1.53.

Additional material examined. Queensland: 3km W Cape Tribulation (Monteith,G.B.) (ANIC); 3.5km W of Cape Tribulation (Site 7) (Monteith,G.B.) (ANIC); Thornton Peak (Williams,S.) (QMBA).

Comments. Leptomyrmex pilosus is restricted to rainforest to the west of Cape Tribulation, Queensland. Morphologically it is similar to L. aitchisoni but is readily distinguished by the abundant pilosity on all surfaces.

Figures

FIGURES 13–18. Leptomyrmex pilosus sp. n. holotype worker. Fig. 13, front of head; Fig. 14, lateral view of body; Fig. 15, dorsal view of body. Leptomyrmex ramorniensis sp. n. worker. Fig. 16, front of head; Fig. 17, lateral view of body; Fig. 18, 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.