Dolichoderus formosus Clark

Shattuck, Steven O. & Marsden, Sharon, 2013, Australian species of the ant genus Dolichoderus (Hymenoptera: Formicidae), Zootaxa 3716 (2), pp. 101-143 : 119-120

Dolichoderus formosus Clark

( Fig. 11 )

Dolichoderus formosus Clark, 1930: 265 .

Dolichoderus occidentalis Clark, 1930: 268 (new synonym).

Types. Dolichoderus formosus : 7 worker syntypes from Mundaring [approx. 31°54'S 116°10'E] (3 in MCZC, 3 in WAMP, 1 in MVMA); 1 worker and 1 queen syntype from Hovea [approx. 31°53'S 116°06'E] (MVMA); additional material from Armadale and Mt. Dale [approx. 32°08'S 116°18'E], Western Australia. Dolichoderus occidentalis : Holotype worker from Albany [approx. 35°00'S 117°52'E], Western Australia (MVMA).

Diagnosis. Pale markings absent from lower margin of the eyes; head dark brown to black and similar in colour to gaster; sculpturing pattern of head and pronotum, with large but shallow and closely spaced foveae; in dorsal view the pronotum with only weakly defined shoulders, with the area between the shoulders more strongly convex to flat; pronotum and propodeum lacking spines; dorsum of propodeum weakly and evenly convex, the length shorter (at most approximately the same length) than the posterior face, with a narrow carina separating the dorsal and posterior faces; posterior face of propodeum weakly concave, separated from the dorsal face by a distinct carina; mesosoma with erect hairs but few to no appresssed pubescence; gaster dark brown to black with little or no pubescence; tibiae with erect or suberect hairs.

Dolichoderus formosus is similar to D. canopus , but is distinguishable by the large, shallow and closely spaced foveae on the dorsum of the head and pronotum, which are distinctly striate on the lateral pronotum. This species most closely resembles D. nigricornis but can be distinguished by having the head colour similar to the gaster (dark brown to black) compared to the lighter coloured head (reddish to reddish-brown) and dark gaster (dark brown to black) in D. nigricornis , and in lacking appressed pubescence from the mesosoma and gaster.

Worker description. See Fig. 11 . Body colour varying from red to black with mandibles, antennae and legs varying from reddish-brown to brown. Sculpturing ranging from smooth and shiny to weakly matte. Otherwise similar to that figured.

Measurements (n=5). CI 78–84; EI 28–32; EL 0.25–0.27; HL 1.05–1.15; HW 0.84–0.95; ML 1.43–1.60; MTL 0.76–0.86; PronI 70.85–76.37; PronW 0.59–0.70; SI 112–123; SL 1.02–1.11.

Material examined. South Australia: Cape Borda, Kangaroo Island (Lowery,B.B.) (ANIC); Kangaroo Is., 2km S Ravine des Casoars (Greenslade,P.J.M.) (ANIC); Kangaroo Is., N of Breakneck R. (Greenslade,P.J.M.) (ANIC); Kangaroo Is., S Breakneck R. (Greenslade,P.J.M.) (ANIC); Lincoln NP (Lowery,B.B.) (ANIC); Yorke Peninsula, Innes Nat. Park (Greenslade,P.J.M.) (ANIC); Western Australia: 1km SE of Brookton (Heterick,B.E.) (JDMC); 1km W of Nalya (Heterick,B.E.) (JDMC); 30km N of Eneabba (Heterick,B.E.) (JDMC); 7.5km SE of Brookton (Heterick,B.E.) (JDMC); Albany (Clark,J.) (ANIC); Armadale (Clark,J.) (ANIC); Bungulla (Greaves,T.) (ANIC); Caiguna RH (Heterick,B.E.) (JDMC); Chittering Valley Rd. (Heterick,B.E.) (JDMC); Dryandra SF (Norwood,C.) (JDMC); Jacup Nth Rd. (Heterick,B.E.) (JDMC); Mundaring (Clark,J.) (ANIC); Nerren Nerren Station (WAM/CALC) (JDMC); Stirling Range (Lowery,B.B.) (ANIC); Whicher Range (Jacobs,M.) (JDMC).

Comments. Dolichoderus formosus occurs in two distinct regions, one in south-western Western Australia, the other in south-central coastal South Australia. It is found in mallee and scrub habitats and nests under rocks.

Figures

FIGURE 11. Dolichoderus formosus, worker from Armadale, Western Australia (ANIC 32 - 061196). A. Front of head; B. Side of body; C. Top of body; D. Distribution of material examined.