Pheidole bifurcus Donisthorpe 1941

Original description [1]

Pheidole (Pheidolacanthinus) bifurcus n. sp.

Soldier. Reddish brown, thorax and gaster darker, mandibles chestnut red, antennae and legs brownish yellow, funiculus, articulations of joints of legs and tarsi lighter, masticatory border of mandibles, eyes and anterior border of head narrowly black. Body clothed with sparse moderately long outstanding yellow hairs.

Head without mandibles as broad as long, subparallel, posterior angles rounded, posterior border deeply sinuate in middle; mandibles massive, very shining, masticatory border unarmed and with 4 punctures; clypeus notched in centre of anterior border, flat, smooth and shining with a small raised tubercle in middle; frontal area indistinct with a few small longitudinal striae at base; a deep smooth furrow extends from base of frontal area to the sinuation in posterior border of head dividing posterior portion of head into two lobes; there is also an indication of a curved transverse depression crossing from eye to eye similar to that in singularis Smith, but much less marked; the head is longitudinally striate; the striae break off towards base into faint network; scrobes shallow and broad at base, reaching considerably beyond eye, not striate longitudinally, faintly rugosely punctured with a transverse raised ridge or two; eyes small, but convex, situated at sides of head in front of the centre; antennae 12-jointed, moderate; scapes reaching about i of length of head, 3-jointed club of funiculus large, long, last joint about as long as the two preceding taken together. Thorax shorter than head, smooth and shining except sides of epinotum which are obliquely striate; pronotum armed with two short sharp curved spines, projecting outwards and slightly downwards at apex; mesonotum with a small raised transverse ridge in centre; epinotum separated from mesonotum by a deep furrow, and armed with two short sharp divergent spines projecting upwards; petiole narrow with rather long peduncle, and narrow node rounded above; post-petiole transverse considerably broader than petiole, convex above and armed on each side with a short-pointed projection, or tooth. Gaster short oval, smooth and shining. Long. 4 mm.

This species is allied to singularis Smith, but differs in many important particulars. It is darker in colour, the transverse impression on head is much less evident, the lobes of the head are much more evenly rounded at sinuation in centre of posterior border, the striae or raised ridges on the head are considerably finer, not so close, and the interstices less deep. In sing·ularis the posterior part of the head is much more rugose, the pronotum is longitudinally striate, and the post-petiole does not possess the projection at sides.

Worker. Head oval, narrowed in front and behind, posterior border narrowly margined, and with sharp posterior angles; mandibles, long, curved, masticatory border armed with short fine teeth; clypeus smooth, shining, convex above, anterior border rounded; frontal area fairly distinct; cheeks longitudinally striate; eyes prominent, situated on sides of head before the middle; antennae long, scape extending beyond posterior border of head by about half its length. Thorax longer than head, slender, smooth and shining except at episternite of mesothorax and sides of epinotum, where it is closely covered with small raised tubercles. Pronotum with sides rounded not as broad as head, armed with two short projecting moderately divergent spines; mesonotum narrow with a short raised transverse ridge and a small tubercle on each side of the ridge; suture between mesonotum and epinotum deep, epinotum armed with two small divergent spines pointing slightly backwards and bifid at apex, the posterior fork being a little the longer; petiole narrow, peduncle long, node at apex small and rounded; postpetiole small, slightly narrowed in front, rounded above and at sides and broader than petiole. Gaster small smooth, shining, oval. Long. 2'5 mm.

Type in B.M. (N.R.). Described. from six workers and one soldier taken by Miss L. E. Cheesman in Dutch New Guinea, Waigeu Island, Camp Nok, 2500 ft., April, 1938, nesting under bark. Tube 18.

References