Aphaenogaster kimberleyensis, Shattuck, Steven O, 2008

Shattuck, Steven O, 2008, Australian ants of the genus Aphaenogaster (Hymenoptera: Formicidae), Zootaxa 1677, pp. 25-45 : 31-33

Aphaenogaster kimberleyensis sp. n.

( Figs 7, 8 , 21, 22 , 26 )

Types. Holotype worker, Australia, Western Australia, 6km E Surveyors Pool Camp, Mitchell Plateau, 14°37’48”S 125°37’48”E, 4 May 1992, S. O. Shattuck, Eucalyptus woodland (ANIC) (ANIC32-017982); paratype workers, 9 (same data as holotype) (ANIC32-017983) (ANIC, MCZC).

Diagnosis. Hairs on venter of head randomly distributed and not forming a distinct psammophore ( Fig. 8 ); head relatively narrow ( Fig. 21 ), its posterior margin broadly arched in full face view ( Fig. 7 ); scape relatively long ( Fig. 22 ); erect hairs on mesosomal dorsum tapering to sharp points; propodeal spines long, the dorsal surfaces of propodeum and propodeal spines connected through a gentle concavity followed by a gentle convexity ( Fig. 8 ). This species is most similar to A. barbara and can be separated from it by the narrower head and longer scapes.

Description. Posterior margin of head broadly arched in full face view, the arch beginning at the occipital collar and with at most a weak angle separating the posterior and lateral margins of the head (often posterior and lateral margins forming a continuous surface). Hairs on venter of head randomly distributed and not forming a distinct psammophore. Mandibular sculpture composed of irregularly sized striations. Erect hairs on mesosomal dorsum tapering to sharp points. Propodeal spines long. Dorsal surfaces of propodeum and propodeal spines connected through a gentle concavity followed by a gentle convexity (so that the base of each spine is raised slightly above the dorsal surface of the propodeum). Petiolar node (in dorsal view) slightly longer than broad.

Measurements. Worker (n = 7). CI 83–86; EI 17–20; EL 0.19–0.22; HL 1.25–1.38; HW 0.04–1.17; ML 1.83–2.02; MTL 1.25–1.43; SI 149–157; SL 1.63–1.80.

Material examined (in ANIC unless otherwise noted). Northern Territory: Kakadu NP, Round Jungle. Western Australia: 6km E Surveyors Pool Camp, Mitchell Plateau (Shattuck,S.O.); Glenelg River (Andersen,A.N.); Mt. Trafalgar, Kimberley region (Majer,J.D.) ( ANAC, JDMC).

Comments. Aphaenogaster kimberleyensis occurs in forested areas ranging from Eucalyptus and Allosyncarpia woodlands to rainforests. Nests are in sandy soil.

This species is very similar to A. barbara but the limited material currently available suggests that two species are involved. Specimens here considered to belong to A. kimberleyensis have narrower heads ( Fig. 21 ) and longer scapes ( Fig. 22 ) compared to specimens placed in A. barbara . It should be noted that these differences are slight and that some smaller specimens of both species do overlap, but the majority of specimens (especially larger ones) show little overlap. No other characters could be found which differ between these two sets of specimens. Given that these two species are currently allopatric (compare Figs 24 and 26 ) it is possible that only a single variable species is involved. However, the characters used here to separate these species (head shape and scape length) have proven to be reliable in diagnosing other species in the genus (species with numerous additional supporting characters). Given this, these differences are taken as being significant and suggest that two separate species are present.

Figures

FIGURES 7 – 12. A. kimberleyensis sp. n., holotype worker: Fig. 7, front of head; Fig. 8, lateral view of body. A. longiceps (Smith), worker: Fig. 9, front of head; Fig. 10, lateral view of body. A. mediterrae sp. n., holotype worker: Fig. 11, front of head; Fig. 12, lateral view of body.

FIGURES 21 – 22. Fig. 21, head length versus head width measurements for A. barbara and A. kimberleyensis; Fig. 22, scape length versus head width measurements for A. barbara and A. kimberleyensis.

FIGURES 24 – 29. Distribution of material examined during this study: Fig. 24, A. barbara; Fig. 25, A. barbigula; Fig. 26, A. kimberleyensis; Fig. 27, A. longiceps; Fig. 28, A. mediterrae; Fig. 29, A. poultoni.