Pogonomyrmex lagunabravensis Johnson NEW SPECIES
Holotype worker:
Worker
Diagnosis. The
combination of: (1) striae present on first gastral tergum, (2) longitudinal rugae on promesonotum very
regular, subparallel/ parallel, (3) anterior margin
of pronotum usually with one to several transverse rugae that continue onto pronotal
sides, (4) longitudinal rugae adjacent to mid-line of
cephalic dorsum subparallel/parallel, rugae continuing onto clypeus, and (5) superior propodeal spines reduced to tubercles, blunt to acuminate denticles, or very small triangular teeth uniquely
characterize this species.
Measurements
– holotype (n
= 12 paratypes). HL 1.60
(1.48-1.73); HW 1.65 (1.45-1.79); MOD 0.35 (0.33-0.40); OMD 0.39 (0.35-0.48);
SL 1.25 (1.00-1.29); PNW 1.08 (0.95-1.15); HFL 1.62 (1.33-1.77); ML 1.83
(1.68-2.03); PW 0.41 (0.33-0.43); PPW 0.56 (0.51-0.60). Indices: SI 75.76 (65.79-78.21); CI 103.12
(97.32-104.17); OI 21.21 (21.23-24.83); HFI 98.18 (87.50-101.33).
Description. Head subquadrate to
quadrate (CI = 97.32-104.17); posterior margin flat to weakly convex in
full-face view. Longitudinal cephalic rugae prominent, rugae along
mid-line subparallel/parallel and continue onto
clypeus; interrugal spaces moderately granulate-punctate, weakly shining.
Vertex rugose; interrugal
spaces weakly granulate, weakly shining to smooth and shining. Anterior margin of clypeus moderately concave,
dorsum with numerous suparallel longitudinal rugae. Mandible with
six teeth; mandibular dorsum coarsely striated. MOD ranging from 0.21-0.25x
HL. Eyes in profile situated
slightly anterior to middle of head, OMD = 0.97-1.27x MOD. In full-face view, eyes protruding slightly
beyond lateral margins of head. Antennal
scapes (SI = 65.79-78.21) failing to reaching
posterior corners of head by about the length of the basal funicular
segment. Antennal scapes
usually weakly to moderately striate, interstriae
weakly to moderately punctate, weakly shining to
smooth and shining; basal flange moderately well developed with carinate margin. Psammophore well developed.
Mesosomal profile
flat to weakly convex; all mesosomal surfaces with
prominent widely spaced, regular, subparallel/parallel
rugae.
In dorsal view, pronotal humeri
enlarged, strongly angulate, especially in lateral
view. Promesonotal suture usually
present; posteromedial portion of pronotum
weakly to moderately depressed below surrounding surfaces. Rugae on mesonotum longitudinal, on pronotum
diverging to humeri and continuing on pronotal sides; up to several transverse rugae on anterior margin of pronotum
that continue on pronotal sides. Regular to weakly irregular rugae on mesopleura angle posterodorsally; regular transverse rugae
on dorsum of propodeum traverse ventrally or anteroventrally on sides.
Superior propodeal spines reduced to
tubercles, blunt to acuminate denticles, or very small
triangular teeth. Inferior propodeal spines moderately well developed, wider than
high, triangular, narrowing to broadly rounded to acute tip, height greater
than length of superior spines. Propodeal
spiracles narrowly ovate, facing posterad. Interrugal spaces
on mesosoma weakly to strongly granulate, dull to
weakly shining. Legs weakly
to moderately coriarious, weakly shining to smooth
and shining.
Petiolar peduncle
about as long as petiole, anteroventral margin with a
weak to well developed broadly rounded process. In side view, posterior
surface of petiole weakly convex; petiolar node
asymmetrical with anterior surface notably longer than posterior surface, apex subangulate to angulate. In dorsal view, petiole longer than wide, sides subparallel anterad, slightly narrower posterad,
anterior margin broadly rounded. Sides and posterior surface of petiole with regular transverse rugae. Dorsum
of postpetiole convex in side view; in dorsal view,
widest near posterior margin, narrowing to anterior margin, width and length
similar; transverse to weakly arcing rugae posterad, anterad rugae traversing medially from lateral margin then curving anteriorly to become longitudinal; anterolateral
rugae concentric, curving from lateral to anterior
margin, rarely with all rugae transverse or weakly
arcing to anterior. Density and
coarseness of rugae on dorsum of postpetiole
similar to or slightly denser than those on posterior face of petiole, interrugal spaces weakly granulate, weakly shining to
smooth and strongly shining. Dorsum of first gastral tegum striate, weakly shining.
Erect,
mostly short to medium length, yellowish pilosity
moderately abundant on head, no hairs exceed about 0.7x MOD. Moderately abundant suberect to semidecumbent pilosity on scape; abundant
decumbent hairs on funicular segments.
Legs with moderately abundant suberect
to decumbent yellowish setae. Rest of body with moderately dense, erect, medium-length, yellowish
setae. Head light to dark
ferruginous orange to dark red-orange; mandibles, antennae, clypeus, frontal
lobes, anterior margin of head, petiole, postpetiole
dark blackish-orange to blackish; mesosoma dark ferruginous
orange, usually slightly darker than head; gastral terga light to dark orangish-black,
often with one or more transverse black bands.
Queen
Diagnosis. This caste is diagnosed by: (1) ergatoid, (2) first gastral tergum with fine longitudinal striae,
silky in appearance, (3) anterior margin of clypeus entire, and (4) in dorsal
view, pronotum and mesoscutum
poorly differentiated, mesoscutum with longitudinal rugae, pronotum with transverse rugae.
Measurements
- (n = 12 paratypes).
HL 1.75-1.83; HW 1.77-1.89; MOD 0.39-0.45; OMD 0.41-0.50; SL 1.18-1.34; PNW
1.16-1.25; HFL 1.66-1.80; ML 2.08-2.20; PW 0.43-0.51; PPW 0.68-0.74. Indices: SI 64.48-73.63; CI 99.44-104.00; OI
22.03-24.73; HFI 90.22-98.36.
Description. Ergatoid; in full
face view, head quadrate to subquadrate (CI = 99.44-104.00),
posterior margin flat. Cephalic dorsum
with wavy, longitudinal rugae, medial rugae diverging toward vertex along posterior margin, interrugal spaces moderately granulate-punctate,
weakly shining; vertex rugose, interrugal
spaces smooth and shining. Mandibles
with six teeth, dorsal surface coarsely rugose. Psammophore well
developed.
Mesosoma lacking
all morphological structures related to or for insertion of wings; all mesosomal surfaces with subparallel,
wavy rugae; interrugal
spaces smooth and shining to moderately granulate-punctate,
weakly shining. Pronotum large with wavy transverse
rugae that traverse ventrally on pronotal
sides. Mesoscutum
reduced in size, not extending to pronotal collar;
sides subparallel, converging to bluntly acuminate arch-shaped
anterior margin. Dorsum of propodeum transversely rugose;
superior spines reduced to denticles or small teeth;
inferior spines well developed, much larger than superior spines, triangular
with an acuminate tip. Petiolar peduncle long, anteroventral
margin with weakly to well developed rounded
process. In side view, petiolar node asymmetrical with anterior
surface notably shorter than posterior surface, apex of node subangulate to angulate. Postpetiole convex in profile; in dorsal view, maximum width about equal to
length. Posterior
face of petiole and dorsum of postpetiole with wavy
transverse rugae; interrugal
spaces weakly punctate, weakly shining to shining. First gastral
tergum with fine, longitudinal striae,
silky in appearance. Most body
surfaces with moderately abundant suberect to erect,
short, white to cream-colored setae, longest hairs on posterior terga. Head, pronotum, mesoscutum, first gastral tergum ferruginous orange;
anterior margin of head, clypeus, frontal lobes, mandibles, antennae, legs,
petiole, postpetiole black; pronotal
collar, sides of pronotum, propodeum
blackish, sometimes with an orangish infusion.
Male.
Diagnosis. This caste
is diagnosed by: (1) ergatoid, (2) in side view,
cephalic rugae forming circumocular
whorls posterior to eyes, and (3) notauli present.
Measurements
– (n = 1). HL 1.38;
HW 1.43; MOD 0.42; OMD 0.24; SL 0.55; HFL 1.61; ML 1.92; PW 0.44; PPW 0.63. Indices: SI 38.46; CI 103.62; OI 29.37; HFI
112.59.
Description. Ergatoid, mesosoma lacking morphological structures related to or for
insertion of wings. Mandible
with five teeth on suboblique cutting margin; mandibular dorsum lacking rugae
laterally, very weakly rugose medially. Anterior margin of clypeus
concave, dorsum rugose. Antennal scapes reaching to or near posterior margin of eye, smooth
and shining. Longitudinal rugae on cephalic dorsum weak to prominent, wavy to
irregular; in side view, rugae forming circumocular whorls posterior to eyes, interrugae
moderately granulate, weakly shining.
All mesosomal surfaces with subparallel
irregular rugae, interrugae
weakly to moderately granulate, weakly shining.
In dorsal view, pronotum enlarged and well defined,
mesoscutum reduced in size, arch-shaped, not reaching
pronotal collar; notauli
forming an incomplete V (Figure XX). In
side view, juncture between dorsum of propodeum and propodeal declivity angulate,
superior propodeal spines reduced to acuminate teeth,
inferior propodeal spines poorly developed, wider
than long, apex broadly rounded. Anteroventral margin of petiolar
peduncle with medium sized rounded process.
In side view, anterior face of petiole shorter than posterior face; node
subangulate to weakly rounded. Posterior face of petiole
and dorsum of postpetiole with wavy to irregular
transverse rugae, interrugae
weakly shining. Entire body with
moderately abundant short to long flexuous white hairs, longest on head and mesosoma similar in length to MOD; hairs mostly lacking on
first gastral tergum except
for along posterior margin. Gaster enlarged, first gastral tergum finely striate, weakly shining. Head, mesoscutum, mesoscutellum ferruginous orange to dark ferruginous
orange; petiole, postpetiole, gaster
blackish orange; antennae, frontal lobes, mandibles, legs, propodeum
dark blackish-orange to black (Figure x).
Additional
material examined.
Etymology. The
specific epithet, lagunabravensis,
is derived from this species being collected near Reserva
Laguna Brava, La Rioja Province, Argentina.
Discussion. Pogonomyrmex lagunabravensis is not known to co-occur with any
congeners, but it is similar to several high-elevation species in which the first
gastral tergum is striate
and longitudinal rugae on the promesonotum
are very regular, subparallel/parallel; these similar
species include P. apterogenos,
P. longibarbis, and P. pulchellus. Pogonomyrmex lagunabravensis can be distinguished from P. apterogenos
based on: (1) the medial rugae on the cephalic dorsum
are subparallel/parallel and continue onto the
clypeus, and (2) the superior propodeal spines are
reduced to minute, rounded denticles or
tubercles. In P. apterogenos, the medial rugae on the cephalic dorsum are not subparallel/parallel,
but rather they converge and end near the posterior margin of the clypeus, and
the superior propodeal spines consist of acuminate denticles, small triangular teeth, or rarely short
spines. Pogonomyrmex lagunabravensis can be distinguished
from P. longibarbis
and P. pulchellus
based on the superior propodeal spines. In P.
lagunabravensis,
these spines are reduced to minute, rounded denticles
or tubercles, whereas they consist of acuminate triangular teeth or short
spines in both P. longibarbis
and P. pulchellus.
In
his description of P. andinus,
Kusnezov (1951) listed two localities, San
Antonio de los Cobres, Salta Province (designated as
the type locality for P. andinus – see above), and Refugio del Peñón, La Rioja Province, Argentina. The latter site is two to three km from the
type locality for P. lagunabravensis, and
the three workers (F. Monrós coll.; not examined – FML?) that Kusnezov determined
as P. andinus
are more likely P. lagunabravensis.
REFERENCES