Dolichoderus nigricornis Clark

Shattuck, Steven O. & Marsden, Sharon, 2013, Australian species of the ant genus Dolichoderus (Hymenoptera: Formicidae), Zootaxa 3716 (2), pp. 101-143 : 126

Dolichoderus nigricornis Clark

( Fig. 17 )

Dolichoderus nigricornis Clark, 1930: 264 .

Types. 6 worker syntypes (1 in MCZC; 5 in MVMA) from Tammin [approx. 31°38'S 117°29'E], Western Australia.

Diagnosis. Head reddish to reddish-brown and lighter in colour than dark brown to black gaster; sculpturing pattern of head and pronotum, with large but shallow and closely spaced foveae compared to the indistinct sculpturing pattern of D. canopus ; pale markings absent from lower margin of the eyes; pronotum and propodeum lacking spines; in dorsal view the pronotum with only weakly defined shoulders, with the area between the shoulders more strongly convex to flat; 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 both erect hairs and scattered appressed pubescence; gaster dark brown to black with scattered appressed pubescence; tibiae with erect or suberect hairs.

This species is most similar to D. formosus but can be distinguished from D. formosus by having a head lighter in colour (reddish to reddish-brown) than the gaster (dark brown to black) compared to the similar coloured head and gaster (dark brown to black) in D. formosus , and in having scattered appressed pubescence on the mesosoma and gaster.

Worker description. See Fig. 17 . The available specimens show minor variation in leg colour, which varies from yellowish-red to reddish-brown, but otherwise all material is similar to the individual figured.

Measurements (n=5). CI 79–89; EI 31–35; EL 0.26–0.29; HL 0.92–1.03; HW 0.78–0.90; ML 1.25–1.41; MTL 0.67–0.75; PronI 67.26–71.66; PronW 0.53–0.61; SI 107–122; SL 0.91–1.00.

Material examined. New South Wales: 23mi. W West Wyalong (Lowery,B.B.) (ANIC); Trundle (Lowery,B.B.) (ANIC); South Australia: 15km WSW Blinman, Flinders Ra. (Greenslade,P.J.M.) (ANIC); Fowlers Bay (McAreavey,J.) (ANIC); Koonamore (Greenslade,P.J.M.) (ANIC); Oraparinna, Flinders Ranges (Greenslade,P.J.M.) (ANIC); Victoria: 20km S Ouyen (Shattuck,S.O.) (ANIC); Englewood Floral Reserve (collector unknown) (MVMA); Western Australia: Bunbury (Lowery,B.B.) (ANIC); Irwin (Ward,P.S.) (ANIC); Reabold Hill, Perth (Majer,J.D.) (ANIC); Tammin (collector unknown; Clark,J.) (ANIC).

Comments. Dolichoderus nigricornis is one of the more widespread species, occurring across much of southern Australia. It is known from dry sclerophyll and riparian woodlands where it forages on trees. Nests are in soil under rocks.

Figures

FIGURE 17. Dolichoderus nigricornis, worker from Irwin, Western Australia (ANIC 32 - 061209). A. Front of head; B. Side of body; C. Top of body; D. Distribution of material examined.