Pogonomyrmex cunicularius Mayr 1887
Pogonomyrmex cunicularius Mayr, 1887: 613 (worker, male). Syntypes
examined: 2 workers [NMW], 3 workers [MSNG], URUGUAY, no loc.,
1 male [NMW],
Pogonomyrmex cunicularis var. brevispinus Santschi,
1931: 275 (worker, ergatoid queen). Syntypes examined: 1 worker, 1 ergatoid queen [MACN], ARGENTINA, Entre Ríos: Estación Sosa (Mac Donagh leg.). Kusnezov, 1951: 251 (synonomy under cunicularius; here confirmed). See also Gallardo, 1932: 123 (MACN
worker here designated LECTOTYPE).
Worker
Diagnosis. Within the P. cunicularius-group, the combination
of: (1) in lateral view, node of petiole broadly
rounded, (2) inferior propodeal spines rounded, (3)
superior propodeal spines moderately long, shorter
than distance between bases, and (4) first gastral tergum smooth, strongly shining uniquely characterize this
species.
Measurements – lectotype (n = 16).
HL 2.38 (1.85-2.47); HW 2.07 (1.52-2.10); MOD 0.38
(0.31-0.42); OMD 0.62 (0.45-0.69); SL 1.55 (1.44-1.92);
Description. Head elongate (CI = 81.01-88.21), widest
immediately posterior to mandibles, narrowing posterior to eyes and forming a
broadly rounded vertex; posterior margin flat to weakly convex in full-face
view. Dorsum of head with weak to
moderately strong longitudinal, wavy to irregular rugae
or weakly rugoreticulate, often weaker to indistinct
near posterior margin; in full-face view median rugae
diverging only slightly towards posterior corners of head. Vertex weakly rugose
to weakly to moderately granulate, dull to weakly shining. Cephalic interrugal
spaces weakly to moderately granulate, weakly shining. Anterior margin of clypeus
flat to slightly convex; dorsal surface with more than several subparallel longitudinal or oblique rugae. Mandibles with six teeth; mandibular dorsum coarsely striate. Eyes small, MOD ranging
from 0.15–0.18x HL. Eyes in
profile, situated anterior to middle of head, OMD = 1.36-1.77x MOD; in
full-face view, eyes protruding beyond lateral margins of head. Antennal scapes
long (SI = 74.88-100.00), surpassing vertex by less than length of first
funicular segment; entire scape with longitudinal striae. Basal flange of scape well-developed with
carinate margin. Psammophore poorly
developed, consisting of short to medium-length hairs scattered across ventral
surface of head.
Promesonotal profile moderately convex, propodeum
flat; all mesosomal surfaces with subparallel
irregular rugae to weakly rugoreticulate. In dorsal view, humeral portion of pronotum rounded. Dorsum of promesonotum and sides of pronotum with transverse, oblique, or longitudinal,
irregular rugae to rugoreticulate;
mesopleura with irregular rugae
that angle posterodorsally. Propodeal spines moderately
long, acuminate, shorter than distance between bases; spines connected by well-defined
keel; wavy to irregular transverse rugae on propodeal dorsum traverse ventrally or anteroventrally
on sides. Inferior propodeal spine well-developed, triangular, wider than
high, with a broadly rounded to bluntly angulate tip. Propodeal spiracles narrowly ovate.
Interrugal spaces on mesosoma
smooth to weakly granulate, weakly to strongly shining. Legs long (HFL = 2.09-2.68 mm), weakly to
moderately coriarious to granulate, dull to weakly shining.
Petiolar peduncle about 0.8x length of petiole, anteroventral
margin with bluntly angulate to angulate triangular process. In side view, posterior face of petiole
flattened; petiolar node asymmetrical with anterior
surface shorter than posterior surface, apex of node broadly rounded. In dorsal view, petiolar
node about 1.5x longer than wide, widest near anterior
margin. Sides and posterior
face of petiole with weak to moderately coarse, irregular, transverse rugae, or granulate-punctate. Dorsum of postpetiole
convex in profile; in dorsal view, widest near posterior margin, narrowing to
anterior margin, maximum width about equal to length, strongly granulate-punctate, dull to weakly shining. Dorsum of gaster smooth, strongly shining.
Erect to semi-erect yellowish pilosity moderately abundant on head, variable in length,
longest hairs approaching MOD. Moderately abundant suberect yellowish pilosity on scape; abundant
decumbent hairs on funicular segments.
Legs with moderately abundant subdecumbent
to decumbent yellowish setae. Mesosoma,
petiole, postpetiole, and dorsum of gaster with moderately dense erect setae, mostly similar in
length, longest hairs not exceeding MOD.
Entire body concolorous tannish-orange to tannish-red.
Queen
Diagnosis. Ergatoid, with
small ocelli on head; otherwise as in worker
diagnosis, and as illustrated in Figure x.
This caste is diagnosed by: (1) anterior margin of clypeus flat to
slightly convex, apron lacking clypeal teeth, (2) in lateral view, node of
petiole rounded, (3) inferior propodeal spines wider than
high, apex broadly rounded, and (4) dorsum of first gastral
tergum smooth and polished, strongly shining.
Measurements - (n = 12). HL 2.26-2.66; HW 1.96-2.38; MOD 0.35-0.45; OMD 0.54-0.66;
SL 1.53-1.87;
Male
Diagnosis. This caste is diagnosed by: (1) head elongate
(CI < 90.0), (2) legs long, HFI > 150.0, (3) hairs yellowish-brown
to brownish, and (4) in lateral view, petiolar node
rounded.
Measurements
– (n = 12). HL 1.30-1.77; HW
1.17-1.54; MOD 0.51-0.64; OMD 0.21-0.32; SL 0.38-0.49; HFL 1.98-2.48; ML
2.51-3.25; PW 0.48-0.67; PPW 0.63-0.97. Indices:
SI 24.84-35.66; CI 82.89-92.81; OI 39.61-47.86; HFI 154.69-182.05.
Additional material examined.
Etymology. The specific epithet, cunicularius, (from Latin cunicul-, plus
the Latin suffix –arius, indicates
a miner or burrower), apparently refers to the soil nests excavated by this
species. Mayr
did not discuss the naming of this species, but Kusnezov
(1949) wrote that P. cunicularius
is the only Argentinian species of Pogonomyrmex that
constructs a crater, even though it is relatively small and flat.
Discussion. Pogonomyrmex cunicularius is not
known to co-occur with any other P. cunicularius-group species, but additional collections
may show it to co-occur with both P. pencosensis and P.
serpens. Pogonomyrmex cunicularius can be distinguished from these two
species based on the following characters: (1) in profile, the petiolar node is broadly rounded, (2) the inferior propodeal spines are rounded, and (3) the first gastral tergum is smooth and
strongly shining. In P. pencosensis
and P. serpens: (1) in profile, the petiolar
node is angulate, (2) the inferior propodeal spines have an acute tip, and (3) the first gastral tergum is weakly to
moderately coriarious, dull to weakly shining.
Santschi erected P. cunicularius var. brevispinus because
the propodeal spines were short (no longer than maximum
eye diameter), the petiole was narrower, and postpetiole
slightly longer than wide along posterior margin than in the type specimen. Kusnezov (1951) synonomized
P. cunicularius
var. brevispinus
under P. cunicularius
without discussion, and I concur with his synonomy. The propodeal
spines were slightly shorter in the syntype worker of
P. cunicularius
var. brevispinus
that I examined than in most workers, but their length was within the range of
variation observed among workers. The
width of the petiole and shape of the postpetiole
also were within the range of variation observed among workers. Finally, the syntype
ergatoid queen of P.
cunicularius var. brevispinus did not differ noticeably
from those of P. cunicularius.
REFERENCES