Colobostruma mellea

This rare southern species has been found in malle and heath habitats. Nothing is known of its biology.

Identification
Shattuck (2000) - This species can be separated from most others in the group by the 5- or 6-segmented antennae, the shallowly concave posterior margin of the head and the uniformly rounded dorsal surface of the head without any indication of phragmatism. Separation from Colobostruma sisypha is based on the more elongate and/or irregularly shaped foveae on the dorsum of the head (the foveae are round in sisypha), the sculpture on the lateral surface of the alitrunk consisting of distinct, uniform, closely spaced reticulations (rather than being a mixture of fine punctations overlain with irregular rugae) and in having the angle between the dorsal and posterior faces of the petiole forming an angle of approximately 130° (rather than approximately 90°).

Key to Australian Colobostruma Species

Distribution
This taxon was described and is only known from Australia.

Nomenclature

 *  mellea. Colobostruma mellea Shattuck, in Bolton, 2000: 37 (w.) AUSTRALIA.

With additional material from the southern arid zones of South Australia and Western Australia it is possible that this species and Colobostruma sisypha may prove to represent the same taxon. However, the presently available material suggests that two separate taxa are involved. Within the presently known specimens of mellea, the South Australian material differs from the Western Australian material in being slightly darker and having a dark, infuscated band across the first gastral tergite. In other respects these specimens are very similar and are here placed together in a single taxon.

Worker
HOLOTYPE. TL 2.8, HL 0.63, HW 0.54, CI 86, ML 0.16, MI 25, SL 0.31, SI 57, PW 0.39, AL 0.76. Anterior region of head rounding gradually from the dorsal to lateral surfaces, not phragmotic. In full-face view ridge immediately in front of eye concave. Frontal lobes and lateral margins of clypeus smooth relative to the surrounding surface of the head. Mandibles triangular, their outer margins weakly concave. Hairs absent from dorsum of head. Posterior margin of head broadly concave. Antenna with 5 or 6 segments, the scape strongly elbowed and without a subbasal lobe. In dorsal view the pronotal humeral angles only slightly wider than the medial pronotal surface. Propodeum high, its posterior face approximately as high as the petiolar node and with broad, thin lamellae; in profile the dorsum of the alitrunk broadly convex. Lateral postpetiole drawn outwards into thin flange-like wings, the wings with translucent windows along both their anterior and posterior margins, the windows separated by a narrow band of thickened integument, the anterior windows much smaller than the posterior windows and reduced to narrow bands along the leading edges. First gastral tergite superimposed with weakly defined reticulate sculpturing and with low, closely spaced carinae on the anterior one-quarter to one-third. Body colour yellow, the gaster sometimes with a broad medial infuscated band.

Type Material
Holotype worker, Australia: Western Australia, Tardun, 28°48'S 115°45'E, 400ft, 22.v.1963, mallee (C.T. Mercovich). Paratypes. 10 workers with same data as holotype; 10 workers with same data as holotype except 24.v. 1 963 (ANIC,, ).