Pogonomyrmex mayri Forel 1899

 

Pogonomyrmex (Janetia) mayri Forel, 1899: 61 (worker, male, in footnote). Syntypes examined: 2 workers [AMNH], 2 workers, 1 male [NMW], 3 workers [USNM], 3 workers [ZSM], COLUMBIA, Magdalena: Ciénega; Wheeler & Wheeler, 1953: 112 (larvae); Kugler, 1978: 170 (queen), figs. 1-8 (NMW worker here designated LECTOTYPE).

 

Pogonomyrmex (Forelomyrmex) mayri Forel; Wheeler, 1913: 80. First combination in Forelomyrmex.

 

Pogonomyrmex mayri Forel; Lattke, 1991: 305. First combination in Pogonomyrmex. 

 

Worker

Diagnosis.  The combination of: (1) anterior margin of clypeus convex with medial tooth, (2) longitudinal striae on dorsum of first gastral tergum, (3) superior and inferior propodeal spines long, acuminate, (4) posterior surface of petiole flattened, (5) strongly rugose petiole and postpetiole, and (6) small eyes uniquely characterize this species.

Measurements - lectotype (n = 12). HL 2.12 (1.78-2.19); HW 1.90 (1.63-1.94); MOD 0.31 (0.26-0.30); OMD 0.47 (0.45-0.55); SL 1.63 (1.50-1.74); PNW 1.47 (1.13-1.34); HFL 2.60 (2.03-2.71); ML 2.55 (2.13-2.49); PW 0.37 (0.34-0.43); PPW 0.69 (0.54-0.70).  Indices: SI 85.79 (77.72-104.82); CI 89.62 (87.69-96.63); OI 16.32 (14.51-16.96); HFI 136.84 (121.56-140.41). See also Kugler (1978).

Description.  Head subquadrate to slightly elongate (CI = 87.69-96.63), widest just posterior to eyes, narrowing to vertex; posterior margin strongly concave medially, broadly V-shaped.  Cephalic dorsum, sides, and vertex rugose, rugae variable in height; in full-face view median rugae not diverging toward posterior corners of head.  Cephalic rugae and interrugal spaces strongly granulate, dull.  Anterior margin of clypeus convex with medial triangular tooth, dorsum of clypeus with numerous subparallel, wavy, longitudinal rugae similar to those on cephalic dorsum.  Mandible with six teeth; mandibular dorsum coarsely striated.  Up to several moderately long, curved, bristle-like, amber to brownish hairs project from anterior margin of clypeus and basolateral margin of mandibles.  Eyes small, MOD = 0.13-0.17x HL.  Eyes in profile situated anterior to middle of head, OMD = 1.52-2.00x MOD; no hairs project from between ommatidia.  Antennal scapes long (SI = 77.72-104.82), reaching vertex to surpassing vertex by less than length of basal funicular segment; entire scape with weak longitudinal striae, interrugal spaces strongly granulate, dull.  Basal flange of scape well developed with recurved, carinate margin.  Psammophore poorly developed, consisting of numerous short hairs scattered across ventral side of head.

Mesosomal profile strongly convex; all mesosomal surfaces with wavy rugae that vary in height.  Transverse rugae on sides of pronotum curving dorsally anteriorly and posteriorly, transverse rugae on pronotal collar; dorsum of propodeum with transverse rugae that traverse to spiracle, then angle posteriorly over metapleural lobe.  Propodeum with long acuminate superior spines, bases connected by well defined keel, spines longer than distance between bases; inferior propodeal spines well-developed, acuminate, length approximately 0.3-0.5x that of superior spines; declivitous face of propodeum transversely rugose.  Propodeal spiracles narrowly ovate.  Rugae and interrugal spaces on mesosoma strongly granulate, dull.  Legs strongly granulate, dull.

Petiolar peduncle about 0.5x as long as petiole, anteroventral margin varying from broad translucent process to triangular acuminate spine.  In side view, petiolar node asymmetrical with anterior surface approximately one-half as long as posterior surface, apex of node angulate, posterior surface flattened; all surfaces rugose.  In dorsal view, petiolar node elongate, approximately twice as long as wide, lateral margins slightly convex posteriorly, nearly vertical medially, concave anteriorly, anterior one-third narrowing to acute tip; anterior portion of posterior surface slightly depressed below margins.  Dorsum of postpetiole convex in profile, anterior margin narrowing gradually to helcium; robust in dorsal view, longer than wide; widest near posterior margin, narrowing to truncate anterior margin; dorsum and sides coarsely rugose; ventral process strongly granulate, dull.  Rugae and interrugal spaces on petiole and postpetiole strongly granulate, dull.  First gastral tergum with fine longitudinal striae, dull.

Short to long, erect, amber to brownish hairs abundant on head,

longest > MOD; mostly medium length hairs abundant on mesosoma, petiole, postpetiole, and gastral terga, longest approaching MOD.  Scape with abundant medium length suberect hairs; abundant subdecumbent hairs on funicular segments.  Legs with moderately abundant, short to medium length, suberect setae.  Body concolorous dark reddish-brown to brown, or with postpetiole, gaster, legs slightly lighter reddish-brown. 

Queen

Diagnosis.  Ergatoid, with ocelli indistinct or absent; otherwise as in worker diagnosis, and as illustrated in Figure x.  This caste is diagnosed by: (1) first gastral tergum striate, (2) anterior margin of clypeus with medial tooth, and (3) postpetiole enlarged (PPW > 1.20 mm), wider than long, with fine, wavy, transverse rugae that vary in height.

Measurements - (n = 2). HL 1.50-1.51; HW 1.44-1.52; MOD 0.27-0.28; OMD 0.43-0.47; SL 1.03-1.14; PNW 1.14-1.18; HFL 1.64-1.65; ML 1.99-2.02; PW 0.70-0.74; PPW 1.20-1.25.  Indices: SI 71.53-75.00; CI 96.00-100.66; OI 18.42-18.75; HFI 108.55-113.89.  See also Kugler (1978).

Male

Diagnosis.  This caste is diagnosed by: (1) CI < 75.0, (2) postpetiole more than twice as long as wide, (3) petiole and peduncle not differentiated, forming one broadly rounded segment, and (4) neck very long.

Measurements - (n = 10). HL 1.49-1.72; HW 1.06-1.23; MOD 0.30-0.36; OMD 0.15-0.19; SL 0.22-0.37; HFL 1.47-2.03; ML 1.96-2.41; PW 0.28-0.36; PPW 0.50-0.65.  Indices: SI 20.18-34.91; CI 66.25-74.52; OI 27.52-32.08; HFI 134.51-178.30.  See also Kugler (1978).

Additional material examined.  COLUMBIA: Atlantico: Puerto Columbia, 1970 (USNM). Bolivar: Santa Marta Mountains, Jul. 7, 1920; 1954 (LACM; MCZ; USNM). Cesar: Santa Marta Mountains, Valledupar, Jul. 4, 1920 (LACM). Magdalena: Mamatoco, Jun. 16, 1976 (LACM; MCZ); Río Frio, Feb. 1924; Mar. 20, 1928 (LACM; MCZ; USNM); 5 km SE Río Frio, 50-200m, Aug. 15, 1985 (LACM); 2 km E Orihueca, 20m, Aug. 17, 1985 (LACM); Parque Nacional Tayrona, Guairaca, Mar. 11, 1977 (LACM); Parque Nacional Tayrona, near Neguanje, 60m, Jun. 30, 1976 (MCZ); Santa Ana, Feb. 1924 (USNM); Manantial, May 29, 1976 (MCZ); Cienega, no date (MZUSP; USNM); Digrera, base of mountains near Santa Marta, 100m, Aug. 23, 1976 (LACM; MCZ). Prov. Unknown: Santa Marta Mountains, Jul. 31, 1920 (MCZ). Questionable locales: VENEZUELA: no loc., no date (MCZ).  Taber (1998) indicated that he examined a specimen from Guyana (MCZ), but these specimens were unavailable during this study.

Etymology.  This species was apparently named to honor Dr. Gustav Mayr, who erected the genus Pogonomyrmex in 1868; Mayr also described six South American species of Pogonomyrmex.

 

Discussion.  Pogonomyrmex mayri is a distinctive species that cannot be confused with any congeners.  Additionally, no congeners are known to co-occur with P. mayri. 

REFERENCES

Forel, A. (1899) Biologia Centrali-Americana; or, contributions to the knowledge of the fauna and flora of Mexico and Central America. Insecta. Hymenoptera. Vol. III. (Formicidae.). London.

Kugler, C. (1978) Description of the ergatoid queen of Pogonomyrmex mayri with notes on the worker and male (Hym., Formicidae). Psyche, 85, 169-182.

Lattke, J.E. (1991 ("1990")) Una nueva especie de Pogonomyrmex Mayr de selva húmeda tropical (Hymenoptera: Formicidae). Revista de Biologica Tropical, 38, 305-309.

Taber, S.W. (1998) The World of the Harvester Ants. College Station: Texas A&M University Press.

Wheeler, G.C. & Wheeler, J. (1953) The ant larvae of the myrmicine tribe Myrmicini. Psyche, 59, 105-125.

Wheeler, W.M. (1913) Corrections and additions to "list of type species of the genera and subgenera of Formicidae". Annals of the New York Academy of Sciences, 23, 77-83.