Acropyga rubescens

Nothing is known about the biology of this ant.

Identification
LaPolla (2004) - Worker: 11 segmented antennae; mandible with 5 teeth and indistinct ridges that run along dorsal surface fading toward median portion of mandibles; scapes > 0.9 mm; many erect hairs on head, mesosoma and gaster giving ant a "spiky appearance." Queen: As in worker with modifications expected for caste. Male: As in Acropyga acutiventris, except hairier and penis valve differences. Compare with Acropyga acutiventris.

This species is the largest known Acropyga species, and is closely related to Acropyga acutiventris.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Singapore. Oriental Region: India, Sri Lanka.

Nomenclature

 * . Acropyga acutiventris var. rubescens Forel, 1894c: 418 (w.q.m.) INDIA (Karnataka), SRI LANKA.
 * [Misspelled as pubescens by Chapman & Capco, 1951: 211.]
 * Subspecies of acutiventris: Viehmeyer, 1916a: 146; Emery, 1925b: 28; Chapman & Capco, 1951: 211; Bolton, 1995b: 58.
 * Status as species: LaPolla, 2004a: 33 (redescription); Bharti, Guénard, et al. 2016: 23.
 * Senior synonym of bugnioni: LaPolla, 2004a: 33.
 * Senior synonym of rubens: Emery, 1925b: 28; Bolton, 1995b: 58; LaPolla, 2004a: 33.
 * bugnioni. Acropyga acutiventris subsp. bugnioni Forel, 1911i: 226 (w.q.) SRI LANKA.
 * Subspecies of acutiventris: Emery, 1925b: 28; Chapman & Capco, 1951: 211; Bolton, 1995b: 57.
 * Junior synonym of rubescens: LaPolla, 2004a: 33.
 * rubens. Acropyga acutiventris subsp. rubens Forel, 1911e: 286 (w) (no state data).
 * [Note: this name most probably in error for rubescens.]
 * Junior synonym of rubescens: Emery, 1925b: 28; Bolton, 1995b: 58; LaPolla, 2004a: 33.

LaPolla (2004) - Acropyga rubescens has been elevated to species status based on 6 points of distinction from A. acutiventris: 1) setation of A. rubsecens is distinct: a) much denser hairs in general found across body; b) hairs on posterior margin of head often very long, much longer than seen in A. acutiventris; c) mesosomal hairs longer and denser; 2) A. rubescens larger overall; 3) with longer scapes (higher SI); 4) dorsal mandibular striate sculpture thinner disappearing about mid-way toward mandible articulation point with head; 5) shapes of penis valves differ; 6) both "forms" are sympatric in India/Sri Lanka region.

Worker
LaPolla (2004) - (n=7): TL: 3.39-5.11; HW: 0.891-1.16; HL: 0.915-1.06; SL: 0.914-1.16; ML: 1.07-1.31; GL: 1.35-2.74; CI: 91.53-109.43; SI: 97.39-106.67.

Head: brownish-yellow to reddish-yellow; head about as broad as long; posterior margin concave; covered in a thick layer of appressed hairs, with many scattered, long erect hairs especially along posterior margin; eyes relatively large, placed at lower 114 of head; 11 segmented, incrassate antennae; scape nearly reaches or surpasses posterior margin up to length of pedicel; clypeus broad, slightly convex medially with many erect hairs, the longest ones along anterior clypeal margin; mandible with 5 uneven teeth; 3rd and 5th tooth (from apical to basal) smaller than others; dorsal surface of mandible covered in many erect hairs and with indistinct ridges originating near base of teeth and fading entirely toward middle of mandible; slight gap present between inner mandibular surface and anterior clypeal margin. Mesosoma: brownish-yellow to reddish-yellow; mesosoma covered throughout in dense layer of appressed hairs with scattered erect hairs of varying lengths; pronotum in lateral view typically with short shelf before rising sharply toward mesonotum; mesonotum rounded with many long erect hairs (many times longer than shortest erect hairs); metanotal area distinct; propodeum rounded, below level of mesonotum, propodeal dorsum flat before steep declivity; propodeum with dense layer of erect and appressed hairs. Gaster: brownish-yellow to reddish-yellow, darker than head and mesosoma; petiole thick and erect reaching height of propodeum; yellow to light brownish-yellow; gaster covered in thick layer of appressed hairs with many scattered erect hairs throughout giving a "spiky" appearance.

Queen
LaPolla (2004) - (n= l): TL: 6.16; HW: 1.36; HL: 1.36; SL: 1.34; ML: 2.23; GL: 2.57; CI: 100; SI: 98.53. As in worker with modifications expected for caste.

Male
LaPolla (2004) - (n= l ): TL: 3.52; HW: 0.644; HL: 0.665; SL: 0.611 ; ML: 1.25; GL: 1.6; CI: 96.84; SI: 94.88.

Head: brownish-yellow to reddish-yellow, darker around three prominent ocelli; head about as broad as long; covered in layer of appressed hairs with suberect to erect hairs; eyes large, breaking outline of head in full frontal view; 12 segmented, slightly incrassate antennae; scape surpasses posterior margin by about length of first two funicular segments; clypeus broad, relatively flat, with scattered short erect hairs; mandible with 4 teeth; a gap exists between inner mandibular margin and anterior clypeal margin. Mesosoma: light brownish-yellow to reddish-yellow; pronotum short and collar-like; mesonotum large, rounded anteriorly; mesonotum dorsum flat, with layer of shorter appressed hairs and scattered longer erect hairs throughout; propodeum lower than mesonotum and scutellum; declivity not distinct from propodeum. Gaster: petiole thick and erect; gaster brownish-yellow to reddish-yellow, darker dorsally; covered in dense layer of appressed hairs with scattered erect hairs throughout. Genitalia: in lateral view parameres thick, tapering to a rounded apex; parameres with medial dorsolateral extensions; cuspi short, bent toward approximately middle of digiti, where they meet with short, peg-like teeth at apex; digiti long and erect with short peg-like teeth where cuspi meet, apex rounded.

Type Material
LaPolla (2004):

Acropyga acutiventris rubescens Forel, 1894: 418, (w.q.m.). 10 syntype workers, 2 syntype queens, 3 syntype males, INDIA: Kanara (Bell)   [examined]. The designated lectotype is a worker labeled JSL TYPE # 111 and is deposited at MCZC.

Acropyga acutiventris bugnioni Forel, 1911c: 226 (w.q.). 2 syntype workers, SRI LANKA: no specific locality given  [examined]. NEW SYNONYM.

Acropyga acutiventris rubens Forel, 19l1a: 286 (w.). Holotype worker, no locality provided (depository unknown) [not examined]. Synonym of A. rubescens by Emery, 1925 [probably a miss-spelling of rubescens (Bolton, 1995)] (here confirmed).

References based on Global Ant Biodiversity Informatics

 * Chapman, J. W., and Capco, S. R. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monogr. Inst. Sci. Technol. Manila 1: 1-327
 * Forel A. 1911. Ameisen aus Ceylon, gesammelt von Prof. K. Escherich (einige von Prof. E. Bugnion). Pp. 215-228 in: Escherich, K. Termitenleben auf Ceylon. Jena: Gustav Fischer, xxxii + 262 pp.
 * LaPolla J.S. 2004. Acropyga (Hymenoptera: Formicidae) of the world. Contributions of the American Entomological Institute 33(3): 1-130.