Comprehensive DescriptionRead full entry
Worker, holotype: TL 5.0, HL 1.20, HW 1.08, ML 0.61, WL 1.52, scape L 0.94, eye L 0.13 mm; Cl 90, MI 50.
Paratype worker: TL 5.2, HL 1.21, HW 1.07, ML 0.60, WL 1.53, scape L 0,96, eye L 0.14 mm; Cl 88, MI 50.
With the general characters of the risii HNS group, but mandibles very short, relatively broad toward apices; light brownish-red in color, mandibles and antennae more yellowish. In body form and sculpture like a short-mandibulate A. modicus HNS , but the following additional differences from modicus HNS :
1. Frontal striation obsolete, even inside frontal carinae. Pronotum completely smooth and shining, except for finely transversely striate cervix.
2. Mesonotal disc longer, elliptical, only twice as broad as long, convex, smooth and shining. Anterior edge blunt. Mesonotal saddle only a brief shallow groove, with longitudinal costulae represented only by tiny, indistinct, raised tubercles; area behind this, grading onto propodeal dorsum, vaguely diagonally costulate; propodeal dorsum transversely striate (about 20 striae).
3. Crenulation of ventral mesial margin of mandible reduced, fine, developed only near preapical tooth or angle.
4: Petiolar node like that of modicus HNS , tall and slender, with narrowly rounded apex, but the anterior and posterior slopes in side view nearly perfectly straight in the upper 2/3. As seen from front, lower halves of' node nearly parallel, upper halves convexly rounded and rapidly tapered to narrowly rounded apex, with just a hint of nippling near apex. Brief anterior peduncle present.
Meso- and metapleura smooth and shining except for borders of short striae along the anteroventral edges and posterior ends of the metapleura; mesopleuron with distinct transverse suture. Head, mandibles, legs (except finely punctulate tibiae and tarsi), node and gaster smooth and shining. Standing hairs numerous, finé and generally distributed over dorsal surfaces of body, underside of gaster, scapes and legs, mostly about 0.05 mm long, but 0.1 mm or longer on pronotum and gastric dorsum (many longer in A. modicus HNS ). Underside of head with moderately abundant suberect pubescence; mandibles with fine appressed pubescence; antennae and legs with fine, dense, decumbent pubescence (sparse on femora).
Holotype (MCZ) and a paratype (BMNH-London) very similar workers taken together on Mt. Apo, Mindanao Island, southern Philippines at "5-6000 ft", or about 1520-1830 m, by C. F. Clagg.