Pheidole purpurea, Longino, J. T., 2009

Longino, J. T., 2009, Additions to the taxonomy of New World Pheidole (Hymenoptera: Formicidae)., Zootaxa 2181, pp. 1-90 : 67-70

Pheidole purpurea new species

Figure 19

Holotype major worker. Mexico, Chiapas: 21km SW Salto de Agua, 17.38542°N 92.42802°W, ±200m, 180m, 15 Jun 2008 (LLAMA#Ba-A-08-3-01-10) [ UNAM, unique specimen identifier CASENT0609143].

Paratypes: major and minor workers. Same data as holotype; same data but LLAMA#Ba-A-08-3-03-18 and Ba-A-08-3-04-18 [ BMNH, CAS, FMNH, INBC, JTLC, LACM, MCZ, MHNG, MIZA, MZSP, UCD, UNAM, USNM].

Geographic Range

Mexico (Chiapas).

Diagnosis

With the morphometric profile of P. dentata, P. mooreorum , and P. hyatti . Minor worker: color dark red brown to black and often with a metallic purple sheen versus color usually lighter orange brown ( dentata , hyatti ) and never with a purple sheen ( dentata , hyatti , mooreorum ); posterior margin of vertex evenly rounded in face view versus somewhat flattened medially ( dentata ); pronotum usually foveolate with small shiny patches dorsally versus pronotum usually with foveolate sculpture reduced or absent ( mooreorum ). Major worker: irregular patches of faint foveolate sculpture and/or variable extent of reticulate rugulae on much of posterior face versus posterior half of face smooth and shining ( dentata , mooreorum ); base of scape narrower than broader distal portion versus basal bend of scape strongly flattened, as wide as distal scape ( hyatti ).

Description of minor worker.

Measurements (paratype): HL 0.66, HW 0.55, HLA 0.24, SL 0.85, EL 0.15, ML 0.86, PSL 0.04, PMG 0.03, SPL 0.03, PTW 0.11, PPW 0.16, CI 83, SI 156, PSLI 6, PMGI 4, SPLI 4, PPI 146.

Measurements (n=13): HL 0.63-0.73, HW 0.53-0.63, SL 0.81-0.91, CI 82-88, SI 134-157. Face smooth and shiny, occasionally with faint patches of foveolate sculpture; margin of vertex rounded; occipital carina narrow, usually visible in full face view; scape with abundant erect setae longer than maximum width of scape; promesonotal groove present; propodeal spines present, short, upturned; pronotum varying from entirely foveolate to mostly smooth and shining, always with at least faint foveolation laterally; katepisternum and propodeum foveolate; abundant flexuous suberect setae on promesonotal dorsum; dorsal (outer) margin of hind tibia with abundant suberect setae, longest subequal in length to maximum width of tibia; first gastral tergum smooth and shining, occasionally with small area of faint foveolate sculpture near postpetiolar insertion; gastral dorsum with abundant, flexuous setae; color dark red brown to black, with a metallic purple sheen that varies from very strong to completely absent.

Description of major worker.

Measurements (holotype): HL 1.18, HW 1.12, HLA 0.37, SL 0.89, EL 0.20, ML 1.10, PSL 0.07, PMG 0.03, SPL 0.05, PTW 0.19, PPW 0.28, IHT 0.40, OHT 0.50, CI 96, SI 79, PSLI 6, PMGI 3, SPLI 4, PPI 148, HTI 80.

Measurements (n=11): HL 1.09-1.25, HW 1.02-1.17, SL 0.85-0.98, CI 92-96, SI 75-89. Mandibles smooth and shiny with abundant subdecumbent flexuous setae; clypeus smooth and flat with shallow anterior notch; face sculpture shallow but never smooth and shiny, composed of variable combination and distribution of faint foveolate sculpture and reticulate to longitudinal rugae, occasionally with posteromedian portion smooth and shining, but then with conspicous piligerous puncta; head with abundant suberect setae projecting from sides of head in face view; scape faintly microfoveolate, subterete at base, with abundant erect setae as long as maximum width of scape; hypostomal margin straight; median tooth a small rounded nub or absent; inner hypostomal teeth thin, sharp, widely-spaced and close to outer hypostomal teeth; promesonotal groove impressed, conspicuous; propodeal spines present, short, upturned; pronotum and katepisternum moderately to faintly foveolate, overlain with shallow reticulate rugae; propodeum foveolate; abundant flexuous suberect setae on mesosomal dorsum; dorsal (outer) margin of hind tibia with abundant suberect setae, longest subequal in length to maximum width of tibia; dorsum of postpetiole foveolate; first gastral tergite largely smooth and shining, with small area of faint foveolate sculpture near postpetiolar insertion, gastral dorsum with abundant flexuous suberect setae; color as in minor worker.

Biology

Pheidole purpurea occurs in mesophyl forest throughout the state of Chiapas, Mexico, from sea level to nearly 1700m. It can be a common epigaeic forager, recruiting rapidly to baits on the ground and often recruiting major workers to baits. A nest was observed beneath a stone.

Etymology

The name is in reference to the violaceous reflections of the cuticle.

Comments

Pheidole purpurea shows abundant geographic variation in traits, and some intra-populational variation. The metallic purple sheen is very strong in some populations (lowland areas of Lacandon rainforest, mid-elevation Pacific slope of southern Sierra Madre de Chiapas), faint in others (Laguna Metzabok and Naha, 500-1000m in the Lacandon area), and absent in others (mid-elevation sites in central and northern portions of Sierra Madre de Chiapas). Foveolate sculpture on the lateral pronotum is usually well developed. A population in the central portion of the Sierra Madre de Chiapas (near Custepec) has the faintest pronotal sculpture observed among all the material examined (that and the lack of purple sheen make minor workers indistinguishable from P mooreorum at the same site). Two minor workers from the northern end of the Sierra Madre de Chiapas (Sierra Morena), tentatively identified as P. purpurea , have the opposite extreme, with the heaviest pronotal sculpture observed.

Additional material examined

MEXICO: Chiapas, Sierra Morena, 16°09'15"N, 93°35'23"W, 1150m (J. Longino); Custepec, 15°42'46"N, 92°56'25"W, 1660m (LLAMA); 13.7km NW Metzabok, 17°11'26"N, 91°44'15"W, 540m (R. S. Anderson); 2km S Playon de la Gloria, 16°08'19"N, 90°54'05"W, 170m (LLAMA); 12km NW Flor de Cafe, 16°08'25"N, 91°16'17"W, 520m (R. S. Anderson); 8km SE Salto de Agua, 17°30'57"N, 92°18'10"W, 100m (LLAMA); Lago Metzabok, 17°07'32"N, 91°37'51"W, 570m (LLAMA); 8km SE Salto de Agua, 17°30'51"N, 92°17'41"W, 70m (LLAMA); Naha, 16°58'47"N, 91°35'08"W, 860m (LLAMA); 15km ENE Huixtla, 15°11'N, 92°20'W, 1200m (I. Perfecto).