Pogonomyrmex naegelii Forel 1878
Pogonomyrmex naegelii Forel, in Emery, 1878: X (worker, name made
available); Forel 1886: XLI (worker description). Syntypes
examined: 2 workers [MSNG], 1 worker [USNM],
Pogonomyrmex (Ephebomyrmex) naegelii
Forel; Wheeler, 1902: 390. First combination in subgenus Ephebomyrmex.
Pogonomyrmex (Ephebomyrmex) venezuelensis Weber 1943: 69, fig. 2 (incorrectly
captioned as Leptothorax
anduzei (worker). Syntypes
examined: 1 worker [MCZ], VENEZUELA, Anzoátegui: from the llanos about 15 km
north of Soledad, across from Ciudad Bolivar (N.A. Weber leg., 27 January 1935).
Kempf, 1960: 428 (synonomy
under naegelii:
here confirmed) (MCZ worker here designated LECTOTYPE).
Pogonomyrmex (Ephebomyrmex) venezuelensis ssp. rupununi Weber 1943: 71 (worker). Types examined: holotype worker, 1 paratype worker [MCZ], #5606,
Ephebomyrmex naegelii Forel; Kempf,
1972: 106. First combination in Ephebomyrmex.
Pogonomyrmex naegelii
Forel; Lattke, 1991: 305. Revived combination in Pogonomyrmex.
Worker
Diagnosis. Within the P. naegelii-group,
the combination of: (1) approximately 8-10 coarse longitudinal rugae between frontal lobes (2) a small lobe projects
dorsally from anterior margin of antennal fossa, (3) peduncle
and anterior face of petiole meet at obtuse angle, (4) in dorsal view,
posterior face of petiole narrow, width similar to only slightly greater than
distance between tips of superior propodeal spines,
and (5) longest hairs on mesosoma rarely exceeding
0.7-0.8x MOD uniquely characterize this species.
Measurements
– lectotype (n =
31 + 1 paralectotype). HL 1.15 (1.05-1.23);
HW 1.15 (1.06-1.20); MOD 0.24 (0.22-0.28); OMD 0.28 (0.21-0.31); SL 0.84 (0.80-0.94);
PNW 0.78 (0.69-0.84); HFL 1.15 (0.95-1.20); ML 1.34 (1.20-1.46); PW 0.30 (0.28-0.36);
PPW 0.45 (0.40-0.49). Indices: SI
73.04 (68.97-85.45); CI 100.00 (91.53-106.25); OI 20.87 (20.17-24.30); HFI
100.00 (84.82-103.64).
Description. Head subquadrate to
quadrate (CI = 91.53-106.25), widest just posterior to eye; posterior margin
flat to weakly concave. Longitudinal cephalic rugae prominent,
usually moderately to strongly rugoreticulate
especially medial to eyes and near posterior margin; approximately 8-10 coarse
longitudinal rugae between frontal lobes; in
full-face view median rugae not diverging toward
posterior corners of head. In side view, area posterior to eyes moderately to strongly rugoreticulate; vertex rugose to rugoreticulate.
Cephalic interrugal spaces moderately to
strongly granulate, dull to weakly shining.
Anterior margin of clypeus flat to weakly concave, dorsal
surface with numerous subparallel longitudinal rugae; a small lobe projects dorsally from anterior margin
of antennal fossa. Mandible with six teeth; mandibular dorsum coarsely striate. Up to several moderately long, curved,
bristle-like, yellow-brown to brownish hairs project from anterior margin of
clypeus and basolateral margin of mandibles. MOD ranging from 0.19-0.25x
HL. Eyes in profile situated
anterior to middle of head, OMD = 0.84-1.25x MOD. Antennal scapes
moderately long (SI = 70.83-85.45), failing to reach vertex by 1.0-1.5x length
of basal funicular segment; entire scape with strong
longitudinal striae, dull to weakly shining. Basal flange of scape
flattened and well developed with carinate
margin. Psammophore
poorly developed, consisting of short to medium length hairs scattered across ventral
side of head.
Mesosomal profile
convex; all mesosomal surfaces rugoreticulate
to vermiculate. Metanotal sulcus sometimes
slightly to moderately impressed. Dorsum of promesonotum and sides of pronotum
rugoreticulate-vermiculate. Mesopleura with highly
irregular rugae angling posterodorsally
to rugoreticulate-vermiculate. Dorsum and sides of propodeum with irregular to very irregular transverse rugae to occasionally rugoreticulate
to vermiculate. Propodeum with moderately long, acuminate spines connected
by well defined keel; spine length approximately 0.7-0.8x distance between bases. Inferior propodeal
spines well-developed with acute tip, length approximately 0.5-1.0x that of
superior spines, base wider than length of superior spines; inferior and
superior spines connected by crest that defines the propodeal
declivity. Propodeal spiracles ovoid to
circular facing posterad. Interrugal spaces
on mesosoma weakly to strongly granulate, dull to
weakly shining to smooth and strongly shining.
Legs moderately coriarious,
weakly shining.
Petiolar peduncle about
as long as petiole, anteroventral margin with weakly
to strongly developed triangular process.
In side view, petiolar node asymmetrical with
anterior surface shorter than posterior surface; apex of node weakly rounded to
subangulate; anterior face meeting peduncle at obtuse
angle. In dorsal view, petiolar node longer than wide, widest near middle, narrowing
to spatulate to subangulate
anterior margin; maximal width of posterior face similar to or only slightly
greater than distance between tips of superior propodeal
spines; dorsum and sides strongly rugoreticulate-vermiculate,
interrugal spaces weakly to moderately granulate, weakly
shining. Dorsum of postpetiole
convex in profile; in dorsal view, postpetiole widest
at or near posterior margin, narrowing from near middle to convex anterolateral margin; maximal width about equal to length;
dorsum and sides moderately to strongly rugoreticulate
or with several irregular longitudinal to oblique rugae,
interrugal spaces moderately to strongly granulate,
dull to weakly shining. Ventral process of postpetiole large, bulbous,
height similar to dorsal portion of postpetiole. First gastral
tergum moderately to strongly coriarious,
weakly shining, to smooth and strongly shining; anterior margin to anterior
half often with weak to moderate strong longitudinal striae.
Erect yellow-brown
to brownish pilosity moderately abundant on head,
similar in length, mostly short, often with one or more longer hairs that
approximate MOD. Moderately abundant suberect to semidecumbent pilosity on scape, abundant decumbent hairs on funicular segments. Legs with moderately
abundant semidecumbent brownish setae. Mesosoma, petiole, postpetiole, gastral terga with moderately
dense, erect setae, mostly similar in length, longest approximately 0.7-0.8x
MOD; hairs on propodeum less dense. Concolorous tan to tannish-brown with darker to blackish gaster.
Alate queen
Diagnosis. As in
worker diagnosis, but with caste-specific morphology of the mesosoma
related to wing-bearing, presence of small ocelli on
the head, and as illustrated in Figure x.
This caste is diagnosed by: (1) small species (HW < 1.35 mm), (2) psammophore poorly developed, consisting of scattered short
hairs on ventral side of head, and (3) posterior face of petiole rugoreticulate to vermiculate.
Measurements
– (n = 11). HL 1.15-1.29; HW
1.15-1.26; MOD 0.24-0.32; OMD 0.23-0.30; SL 0.85-0.98; PNW 0.87-1.01; HFL
1.09-1.30; ML 1.56-1.75; PW 0.34-0.44; PPW 0.50-0.60. Indices: SI 73.91-78.86; CI 95.93-107.83; OI
20.69-25.40; HFI 87.90-108.47.
Ergatoid queen
Diagnosis. As in
worker diagnosis, but with caste-specific morphology of the mesosoma,
presence of small ocelli on the head, and as
illustrated in Figure x. This caste is
diagnosed by: (1) small species (HW < 1.30 mm), (2) mesoscutum,
mesoscutellum, and posterior face of petiole rugoreticulate, and (3) in lateral view, mesosomal profile discontinuous with a break between the mesoscutellum and metanotum and
between metanotum and propodeum.
Measurements
– (n = 6). HL 1.12-1.27; HW
1.17-1.27; MOD 0.23-0.29; OMD 0.23-0.28; SL 0.83-0.94;
Description. Ergatoid. Small species (HW =
1.17-1.27 mm), in full face view, head subquadrate to
quadrate (CI = 94.49-110.71), posterior margin flat to weakly concave. Longitudinal cephalic rugae
prominent medially, becoming rugoreticulate
laterally. Interrugal
spaces weakly to moderately coriarious, weakly shining. Mandible with six teeth,
dorsal surfaces coarsely rugose. Psammophore poorly
developed, consisting of numerous short hairs scattered across ventral side of
head.
All mesosomal surfaces rugoreticulate. In lateral view, mesoscutum
and mesoscutellum flattened, mesoscutellum
angled upward posteriorly; metanotum
discontinuously connected to mesoscutellum and propodeum. Superior
and inferior propodeal spines moderately well
developed, similar in length. Petiolar peduncle
long, anteroventral margin with small to moderately
well developed acuminate triangular process. In side view, petiolar
node asymmetrical with anterior surface notably shorter than
posterior surface, apex of node angulate. Postpetiole slightly wider than long.
Posterior face of petiole coarsely rugoreticulate,
dorsum of postpetiole finely rugoreticulate;
interrugal spaces weakly to moderately punctuate, weakly
shining. First gastral tergum weakly to strongly
coriarious, dull to weakly shining, with faint to
moderately strong longitudinal striae near base that
sometimes extend over anterior one-half of tergum. Most body surfaces with abundant suberect to erect brownish hairs that are similar in
length, longest approximately 0.5-0.7x MOD.
Body concolorous tannish-brown to orangish-brown,
posterior gastral terga
often slightly darker.
Male
Diagnosis. The combination of: (1) small (HW < 1.15
mm; ML < 2.00 mm), (2) funicular segments covered with very dense, suberect hairs, and (3) anteroventral
margin of peduncle lacking small acuminate spine characterize this species, but
note that males are unknown for P. abdominalis and P.
tenuipubens.
Measurements
- (n = 12). HL 0.89-1.10; HW
0.84-1.08; MOD 0.32-0.42; OMD 0.06-0.18; SL 0.14-0.23; HFL 1.03-1.40; ML
1.51-1.95; PW 0.33-0.43; PPW 0.44-0.58. Indices:
SI 14.00-22.12; CI 94.38-109.18; OI 33.98-42.00; HFI 106.80-136.00.
Additional material examined. ARGENTINA: Buenos Aires: Campana, 10m, Oct. 31, 2002 (ALWC; MLPA); 10 km SE Campana, Dec. 1, 2005 (CSC); Hwy 12 at 9 km N Zárate, 30’, Dec. 3, 2003 (RAJC); Reserva Otamendi,
50’, Dec. 3, 2003 (RAJC); Buenos Aires Zoo, 10’, Jan. 10, 2011 (RAJC); San
Fernando, Aug. 1963 (USNM); Rosas, Aug. 1963 (USNM); Rt
12 at Rivadavia, 340’, Jan. 20, 2011 (RAJC). Córdoba:
Nono, 2940’, Jan. 17, 2008 (RAJC); Rt 20 at 1.0 km N Nono, 2920’,
Jan. 23, 2006 (RAJC); 2.6 km N Nono, Dec. 17, 2006
(CSC); Alta Gracia La Granja, Sierras de Córdoba,
Jan. 1922 (USNM); Rt 5 at 2.4 km N Alta Gracia, 1980’, Jan. 24, 2006 (RAJC); Rt
5 at 3.4 km S Alta Gracia, 1830, Jan. 23, 2006’
(RAJC); 6 km SW Alta Gracia, 600m, Jan. 27, 1995
(MCZ); 22 km WSW Alta Gracia, Jan. 28, 1995 (MCZ); Rt 9 at 6.5 mi E Bell Ville, 390’, Dec. 21, 2005 (RAJC);
Sierra Chica, 3670’, Jan. 23, 2006 (RAJC); La Cruz,
1860’, Jan. 16, 2008 (RAJC); Rt 9 at 3.5 km E Marcos Juárez, 330’, Jan. 14, 2010 (RAJC); Unguillo,
no date (MLPA).
Etymology: The
specific epithet, naegelii
(Latinization of Naegeli), is derived from Carlos Naegeli, who collected the syntype
workers of this species.
Discussion. Pogonomyrmex naegelii co-occurs
with both of the other two P. naegelii-group species.
Pogonomyrmex naegelii can
be distinguished from P. tenuipubens by:
(1) the approximately 8-10 coarse longitudinal rugae
between the frontal lobes, (2) a small lobe that project dorsally from the anterior
margin of the antennal fossa, and (3) the longest
hairs on the psammophore and mesosoma
coarse, >0.5x MOD. In P. tenuipubens,
there are 16-20 fine, weak longitudinal rugae between
frontal lobes, the lobe-like projection from the anterior margin of the
antennal fossa is lacking, and the psammophore and hairs on mesosoma
are very short, delicate (<0.2x MOD).
Pogonomyrmex naegelii can
be distinguished from P. abdominalis by: (1) usually smaller (HW = 1.05-1.23
mm), (2) a small lobe that projects dorsally from anterior margin of antennal fossa, (3) peduncle and anterior face of petiole meet at an
obtuse angle, and (4) width of the posterior face of the petiole is similar to
or only slightly greater than distance between tips of the superior propodeal spines. In
P. abdominalis,
the body is usually larger (HW = 1.14-1.33 mm; Figure X), (2) no small lobe
projects dorsally from anterior margin of antennal fossa,
(3) the peduncle and anterior face of petiole meet at or near a right angle,
and (4) the posterior face of petiole is distinctly wider than distance between
tips of superior propodeal spines.
Weber’s (1943) description of P. (E.) venezuelensis
and P. (E.) venzuelensis
subsp. rupununi
appear to have been driven by biogeography rather than morphology as he notes
that his records from Venezuela and British Guiana (= Guyana) bridge the
considerable distribution gap between Guatemala and southern Brazil, Bolivia,
and Chile. Moreover, it appears that
Weber was unaware of or ignored comparing his specimens with those of P. abdominalis or
P. naegelii
because his paper did not mention either species. His only comment on P. venezuelensis var. rupunini was that this it was
larger and darker, and the gaster more heavily
sculptured, being shallowly reticulate-punctate at
the base compared to P. venezuelensis (Weber, 1943).
Kempf (1960) synonomized
P. venezuelensis
and P. venezuelensis
var. rupunini
under P. naegelii
indicating that the description and figure of P. venezuelensis matched that of P. naegelli, also noting that Dr. Weber failed
to differentiate P. venezuelensis
from other known species in the group. Kempf subsequently synonomized P. venezuelensis
under P. naegelli,
noting that Dr. Brown at the MCZ found no differences between the two forms
when comparing a syntype of P. venezuelensis
with P. naegelli
from several locations. Kempf also indicated that the same applied to P. venezuelensis
ssp. rupunini,
even though neither Kempf nor Brown had examined syntypes of this form.
I have
examined syntypes of P. venezuelensis and P. venezuelensis subsp. rupununi, and both taxa fall within the morphological variation displayed
within a nest series of P. naegelii. Overall, there are no differences between P. naegelii, P. venezuelensis,
and P. venzuelensis
subsp. rupununi,
and the two latter forms are maintained as junior synonyms of P. naegelii. Also note that the types of P. venezuelensis ssp. rupununi are
labeled as P. venezuelensis
myersi (after Myers, who collected the type
series); Weber apparently changed his mind about naming this form while writing
the description.
Kempf (1972) indicated that Guanabara,
Rio de Janeiro, Brazil, was the type locality for P. naegelii. However, I have not seen data to support his assertion
that a specific locality in Río de Janeiro was named as the type locality. REFERENCES