Pyramica rostrata-group

Bolton, B., 2000, The ant tribe Dacetini. With a revision of the Strumigenys species of the Malgasy Region by Brian L. Fisher, and a revision of the Austral epopostrumiform genera by Steven O. Shattuck., Memoirs of the American Entomological Institute 65, pp. 341-369 : 354-355

rostrata-group

DIAGNOSIS OF WORKER

Mandibles in full-face view and at full closure triangular to elongate-triangular, with serially dentate masticatory margins that engage through all or most of their visible length; a small gap usually visible between basal tooth and anterior clypeal margin. In ventral view outer margin of mandible without an inflected prebasal angle. MI 16 - 20.

Dentition. Basal dental row of 7 short triangular teeth, either all about the same size or with alternating very slightly taller and very slightly shorter teeth. Basal lamella not separated from basal tooth or with a very short diastema present. Distalmost 2 teeth of the basal row small, followed by 4 minute denticles and a slightly enlarged apical tooth, giving a total dental count of 12.

Basal lamella of mandible low, triangular to rounded-triangular, not visible or partially visible in full-face view with the mandibles fully closed.

Labrum terminates in a pair of narrow digitate to conical lobes.

Clypeus with anterior margin broad, transverse to shallowly concave in full-face view.

Lateral clypeal margins approximately straight to weakly convex, and feebly convergent anteriorly. In ventral view the lateral clypeal margins extend well beyond the outer margins of the fully closed mandibles through the basal third or more of their length.

Clypeal lateral margins fringed with a continuous row of anteriorly curved spatulate to spoon-shaped hairs; anterior margin with similar but smaller hairs that are curved toward the midline. Clypeal dorsum with numerous small spatulate to spoon-shaped hairs, without any other form of pilosity.

Preocular carina conspicuous in full-face view.

Ventrolateral margin of head between eye and mandible quite sharply angular. Postbuccal impression small to vestigial.

Cuticle of side of head within scrobe reticulate or reticulate-punctate.

Scape short, SI 63 - 70 (in Malagasy species), conspicuously dorsoventrally flattened, the dorsum and ventre converging anteriorly so that the leading edge is a flange or even a thin lamella. Ventral surface of scape behind the leading edge usually distinctly concave.

Leading edge of scape with spatulate to spoon-shaped hairs, some or all of which are curved toward the scape base.

Pronotal dorsum without a median longitudinal carina.

Propodeum with triangular teeth subtended by a lamella on each side that is sometimes broad and engages the teeth through most of their length.

Spongiform appendages well developed on postpetiole; ventral spongiform curtain of petiole may be well developed but in some is vestigial or absent beneath the peduncle. Base of first gastral sternite in profile with a pad of spongiform tissue.

Pilosity. Pronotal humeral hair elongate, straight or flagellate. Cephalic dorsum with curved-clavate to spoon-shaped hairs, almost suborbicular in some. Dorsolateral margins of head without freely laterally projecting elongate simple or flagellate hairs.

Sculpture. Dorsum of head behind clypeus reticulate-punctate. Pleurae, side of propodeum and disc of postpetiole smooth.

The described members of this group are distributed in the Malagasy, Oriental, Malesian, East Palaearctic and Nearctic regions; the group has not yet been found in the Afrotropical, Austral or Neotropical regions, and is also absent from the West Palaearctic. The four species discussed below are known only from Madagascar; the group is discussed in more detail under the Malesian-Oriental-East Palaearctic fauna.