Pogonomyrmex saucius Wheeler & Mann 1914

Johnson, Robert A. & Cover, Stefan P., 2015, A taxonomic revision of the seed-harvester ant genus Pogonomyrmex (Hymenoptera: Formicidae) on Hispaniola, Zootaxa 3972 (2), pp. 231-249 : 239-240

publication ID

https://dx.doi.org/10.11646/zootaxa.3972.2.5

publication LSID

lsid:zoobank.org:pub:6A51EB89-0FE5-4F49-B427-E75459D8A3AF

DOI

https://doi.org/10.5281/zenodo.6095462

persistent identifier

https://treatment.plazi.org/id/03B687EE-FFF1-7C68-FF17-B7386565D8E3

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scientific name

Pogonomyrmex saucius Wheeler & Mann 1914
status

 

Pogonomyrmex saucius Wheeler & Mann 1914

( Figures 6–8 View FIGURE 6 View FIGURE 7 View FIGURE 8 )

Pogonomyrmex (Ephebomyrmex) saucius Wheeler & Mann, 1914: 29 , figs. 10, 11 (worker, male); Olsen, 1934, plate 7, fig. 2. Syntypes examined: 4 workers, 1 male [ AMNH], 1 worker [ LACM], 5 workers, 1 male [ MCZ], 1 worker [ MHNG], 14 workers [ USNM]; HAITI, about one-half mile east of Manneville (W.M. Mann leg, winter 1912–1913) ( LACM worker here designated LECTOTYPE [LACMENT 181990]).

Ephebomyrmex saucius (Wheeler & Mann) ; Kempf, 1972: 106. First combination in Ephebomyrmex .

Pogonomyrmex saucius Wheeler & Mann ; Bolton, 1995: 341. Revived combination in Pogonomyrmex .

Worker. Diagnosis. Small (HW = 1.22–1.33 mm), easily identified by the coarse regular to weakly irregular, subparallel longitudinal rugae on the dorsum and sides of the mesosoma and posterior surface of petiolar node ( Figure 6 View FIGURE 6 ).

Measurements — lectotype (n = 10 + 2 paralectotypes). HL 1.33 (1.26–1.37); HW 1.33 (1.22–1.33); MOD 0.28 (0.25–0.30); OMD 0.33 (0.28–0.34); SL 1.01 (0.90–1.01); PNW 0.90 (0.87–0.95); HFL 1.22 (1.02–1.31); ML 1.63 (1.56–1.81); PW 0.50 (0.42–0.53); PPW 0.58 (0.51–0.62). Indices: SI 75.94 (68.42–79.51); CI 100.00 (94.57– 101.53); OI 21.05 (19.84 –24.00); HFI 91.73 (79.07–102.46).

Queen. Diagnosis. With caste-specific morphology of the mesosoma related to wing-bearing and presence of ocelli on head. Small (HW = 1.15 mm), about the same size as conspecific workers; all surfaces of mesosoma and posterior surface of petiolar node with coarse longitudinal rugae ( Figure 7 View FIGURE 7 ).

Measurements (n = 1). HL 1.23; HW 1.15; MOD 0.29; OMD 0.28; SL 1.00; PNW 1.01; HFL 1.27; ML 1.71; PW 0.41; PPW 0.55. Indices: SI 86.96; CI 93.50; OI 25.22; HFI 110.43.

Description. With caste-specific morphology of the mesosoma related to wing-bearing and presence of ocelli on head. In full-face view, head longer than broad (CI = 93.50), posterior margin flat. Longitudinal rugae on cephalic dorsum prominent, wavy to irregular; interrugae strongly granulate, dull. Mandible with six teeth, dorsal surface coarsely rugose. Eye relatively small, situated anterior to middle of head. Antennal scape moderately to strongly granulate, dull. Psammophore poorly-developed, consisting of short hairs scattered across ventral side of head.

All mesosomal surfaces with subparallel, regular to weakly irregular longitudinal rugae except for sides and dorsum of propodeum where rugae converge posterad. Propodeum with long, well-developed superior and inferior spines, inferior spines about the same length as superior spines. In profile, petiolar node asymmetrical with anterior surface notably shorter than posterior surface, apex of node weakly angulate. In dorsal view, petiolar node slightly longer than wide, widest near middle, tapering to a rounded to spatulate anterior margin. Anterior surface of petiolar node smooth and shining; posterior surface with coarse regular to weakly irregular longitudinal rugae, interrugae weakly granulate, shining. In dorsal view, postpetiole widest near posterior margin, tapering to anterior margin, maximum width about equal to length; all surfaces strongly coriarious, dull. First gastral tergum strongly coriarious, dull. Moderately abundant yellowish-brown to brownish hairs on entire body, longest hairs on head and mesosoma shorter than MOD. Body mostly concolorous dark brown; legs, antennae, and mandibles lighter; postpetiole and first gastral tergum with an iridescent blue to purplish reflection ( Figure 7 View FIGURE 7 ).

Male. Diagnosis. Head, dorsum of mesosoma, and posterior surface of petiolar node strongly granulatepunctate, dull; dorsum of postpetiole weakly granulate-punctate, weakly shining; notauli well-developed ( Figure 8 View FIGURE 8 ). Note that these characters might not be diagnostic because males of P. aterrimus and P. schmitti are unknown.

Measurements. (damaged, unable to measure).

Additional material examined. DOMINICAN REPUBLIC. Pedernales: Pedernales, May 27, 2008 (A Clark; RAJC); Cabo Rojo, 5 m, Sept 9, 1992 (PS Ward; MCZ, UCDC); Parque Nacional Jaragua, 5 m, Mar 31, 2012 (D Lubertazzi; MCZ). HAITI. Quest: Mannville, 1954 (WM Mann; LACM, USNM).

Etymology. Wheeler did not give information regarding the derivation of this name. The specific epithet, saucius (Latin, sauci = wounded, injured, weakened) might refer to the behavior of disturbed workers feigning death, as occurs in some related species.

Discussion and biology. The smaller P. schmitti is the only congener known to occur in sympatry with P. saucius ( Figure 5 View FIGURE 5 ). Pogonomyrmex saucius is easily distinguished by the wavy to slightly irregular longitudinal rugae on the dorsum and sides of the mesosoma and posterior surface of the petiolar node. All other Hispaniolan congeners have rugoreticulate-vermiculate sculpturing on the mesosoma, and the posterior surface of the petiolar node is shining to strongly punctate or rugoreticulate, but never with prominent longitudinal rugae.

Currently, P. s a uc i us is known only from arid, semi-desert habitats at low elevations in south-central Hispaniola ( Figure 5 View FIGURE 5 ). Wheeler and Mann (1914) found nests under stones near sea level in a very arid area that contained desert vegetation such as cacti and thorny bushes; another collection label also indicated that specimens were collected in desert habitats (PS Ward # 11730). Nests of P. saucius contained small numbers of seeds ( Wheeler & Mann 1914). No information is available on colony size, but it is probably small (200– 300 workers) (D. Lubertazzi, pers. comm.).

Little information is available relative to timing of sexual production or mating flights for P. saucius . One alate queen was collected on March 31, and the date for males was given as winter 1912–1913 ( Wheeler & Mann 1914). The queen was small, similar to the size of workers (see discussion under taxonomy, morphology, and ecology). We also examined one aberrant intermorph-like queen ( USNM) that had small wing buds, but her size and shape (especially the mesosoma) was similar to that of workers; she also lacked ocelli and distinct mesosomal sutures (see also Heinze et al. 1992; Johnson et al. 2007; Kusnezov 1951).

We also note that Wheeler & Mann described P. saucius as brownish-black. This coloration agrees with specimens in recent collections and indicates that over time workers in the syntype series have discolored to a light orangish-brown.

AMNH

American Museum of Natural History

LACM

Natural History Museum of Los Angeles County

MCZ

Museum of Comparative Zoology

MHNG

Museum d'Histoire Naturelle

USNM

Smithsonian Institution, National Museum of Natural History

MOD

University of Modena and Reggio Emilia, Department of Biology

UCDC

R. M. Bohart Museum of Entomology

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hymenoptera

Family

Formicidae

Genus

Pogonomyrmex

Loc

Pogonomyrmex saucius Wheeler & Mann 1914

Johnson, Robert A. & Cover, Stefan P. 2015
2015
Loc

Pogonomyrmex (Ephebomyrmex) saucius Wheeler & Mann , 1914 : 29

Wheeler 1914: 29
1914