Melophorus majeri, Agosti, 1997

Agosti, Donat, 1997, Two new enigmatic Melophorus species (Hymenoptera: Formicidae) from Australia, J. New York Entomol. Soc. 105 (3 - 4), pp. 161-169 : 166-168

Melophorus majeri , new species

Holotype worker: Australia, WA, Hassel Road, Jerramungup - Albany (15km SW Welletead), at Mettler Lake Road 100 m left side. 34°40'S 118°36'E. WA, 23.iv.1988, B. Heterick; Holotype deposited at ANIC .

Paratypes: 17 workers, Australia, WA, Hassel Road , Jerramungup - Albany (15km SW Welletead), at Mettler Lake Road 100 m left side. 34°40'S 118°36'E. WA, 23.iv.1988, B. Heterick ; 18 workers Australia, WA, Hassel Road , Jerramungup - Albany (15km SW Welletead), at Mettler Lake Road 100 m left side. 34°40'S 118°36'E. WA, 28.x.1990, D. Agosti ; 1 worker, Australia, WA, Cape Arid NP, Yokinup Bay , xi.1988, A. H. Burbidge. Heath vegetation on quarz soil; pitfall trap . Paratypes deposited at AMNH, ANIC, BMNH, CSIRO-TERC, MCZ, MHNG .

Holotype worker: TL 1.08, HL 0.75, HW 0.45, SL 1.14, EL 0.14, CI 60, El 31, SI 253.

Paratype workers (N = 7): TL 1.08-1.08, HL 0.70-0.75, HW 0.42-0.45, SL 1.04- 1.16, EL 0.12-0.14, CI 58-63, El 29-33, SI 231-267; large workers (soldiers) (N = 2): TL 1.32-1.32, HL 0.92-0.94, HW 0.90-0.94, SL 0.92-0.92, EL 0.18-0.18, CI 98-100, El 19-20, SI 98-102.

Description: Worker:

—Maxillary palps almost as long as head, brownish and rather wide; not flattened

—Maxillary stipes with long erect hairs

—Mandible with four subequal teeth slightly decreasing in size from apical to basal, and with a distinct basal tooth

—Frontal carinae distinctly raised, closely set, forming almost on enclosure for the frontal triangle and the anterior part of the clypeus, which is slightly protruding behind the insertion of the antennae

—Extremely long antennal scape

—Extremely elongate head

—Humeri on pronotum well developed and projecting laterally

—Mesosoma laterally completely flat

—Propodeal spiracle very long, slit shaped, reaching the dorsal outline of the propodeum

—Propodeum armed with two distinct lateral spines

—Petiole almost rectangular, wider than long

—Insertion of petiole into the metanotum not reaching beyond a line spanned between the anteriormost point of the hind coxal cavities

—First gastral segment of Formica type (helcium at the antero-ventral part of the first gastral tergite, and the tergite and stemite meeting in a straight line

—Proventricule short, asepalous

—Body almost without any pubescence

—Body color grayish black

—Surface sculpture densely reticulate; surface matte.

Soldier (large worker):

—Same as worker with the following differences;

—Head with a much wider and larger

—Mesosoma stouter, relatively much higher

—Propodeal spiracle less extended and not reaching the dorsal outline of the propodeum

—Propodeal spine short and blunt

—Petiole squamiform.

Material examined: Holotype and paratypes.

Comment: The morphology of the worker is unique among Melophorus ants. The most conspicuous feature is the elongation of the whole body ( Fig. 9 ), the propodeal spines, as well as the blackish gray coloration. The presence of the dimorphic worker caste, sharing all the diagnostic characters of Melophorus , seems to justify the inclusion of this new species within Melophorus .

Biology: This species was collected in a nest under a piece of wood in a clearing in heath vegetation, and in a pitfail trap. Little is known of this species. It is moving rather nervously on the ground with the antenna almost fully stretched out, almost without an angle between the scape and the funiculus.

Figures

Fig. 9. Melophorus majeri (Paratype worker) in lateral view.