Probolomyrmex greavesi Taylor, 1965

Shattuck, S. O., Gunawardene, N. R. & Heterick, B., 2012, A revision of the ant genus Probolomyrmex (Hymenoptera: Formicidae: Proceratiinae) in Australia and Melanesia, Zootaxa 3444 (1), pp. 40-50 : 43

Probolomyrmex greavesi Taylor

Probolomyrmex greavesi Taylor, 1965: 358 .

( Figs 2 , 7 )

Types. Holotype worker from Mt. Stromlo , A.C. T., 11 Mar. 1933, T. Greaves ( ANIC, ANIC32-011633 ) . Paratypes: 2 workers, 2 queens and 1 male, same data as holotype ( ANIC, 1 worker, 1 queen and 1 male ANIC32-030938 , 1 worker ANIC32-030939 , 1 queen ANIC32-030937 ) ; 3 workers, same data as holotype except 28 Jan. 1933 ( ANIC, ANIC32-011634 ) ; 1 worker from Greenmount , Queensland, 4 Dec. 1949, T. Greaves ( ANIC, ANIC32-011635 ) .

Diagnosis. Petiolar node relatively short and broad and with the anterior and dorsal faces separated by a convexity; subpetiolar process forming a rounded 90° angle anteriorly and with the ventral margin straight; body large (HW> 0.35mm, ML> 0.65mm) and head broad (CI> 66).

Probolomyrmex greavesi is similar to P. latalongus (from Australia) and P. vieti (from Thailand, Vietnam and Indonesia). It differs from P. latalongus by its larger size (HW> 0.35mm and ML> 0.65mm vs. HW <0.33mm and ML <0.65mm in P. latalongus ) and broader head (CI> 66 vs. CI <66 in P. latalongus ), and from P.vieti by the anteriorly angular and ventrally straight subpetiolar process (the process having an anterior tooth and concave ventral surface in P. vieti ).

Worker description. Body light ferruginous brown. Head in full-face view with weakly convex sides and very shallowly concave occipital border. Eye absent. Antenna relatively short. Dorsal outline of mesosoma straight; posterior margin of dorsum of propodeum in dorsal view moderately concave; posterior face of propodeum separated from sides by an angle, the lamella being absent. Petiole including subpetiolar process higher than long, in profile with relatively steep anterior face and convex posterior outline; posterodorsal margin of petiolar node in dorsal view very weakly concave; subpetiolar process developed; its anteroventral portion forming a rounded 90° angle; posteroventral portion of subpetiolar process forming a blunt tooth; ventral surface straight. Abdominal segment III (gastral segment I) in profile relatively short, gently narrowed anteriad in the anterior 2/3; abdominal sternum III weakly convex behind the midlength.

Measurements. Worker (n=5)—CI 67–69; DPetW 0.18–0.20; HL 0.52–0.58; HTL 0.32–0.37; HW 0.36–0.39; LPetI 80–88; ML 0.66–0.77; PetH 0.26–0.29; PetNL 0.22–0.25; PronW 0.26–0.28; SI 83–90; SL 0.31–0.35

Additional material examined (in ANIC except where noted). Australia: Australian Capital Territory: Mt. Ainslie , W Face (Brooks, C.G.) . New South Wales: 23km NW Batemans Bay (Shattuck, S.O.) .

Comments. This was the first species of Probolomyrmex described from Australia and before this study it was generally assumed to be the only species occurring there. However, it is now known that this species is restricted to south-eastern Australia while two separate species occur in northern Australia, P. aliundus on Cape York Peninsula and P. latalongus across much of northern Australia.

Probolomyrmex greavesi has been found in forested sites ranging from a non-native pine plantation through dry sclerophyll and into wet sclerophyll. It is known to nest in soil under rocks. It is one of the rarer Australian ants having been collected only a handful of times.

Figures

FIGURE 2. Probolomyrmex greavesi (holotype, Mt. Stromlo, A.C.T., ANIC32-011633): A. Front of head; B. Side of body; C. Top of body; D. Distribution of material examined.

FIGURE 7. A. Head length versus head width for P. aliundus, P. greavesi and P. latalongus; B. Scape length versus head width for P. aliundus, P. greavesi and P. latalongus.