Pogonomyrmex tenuipubens Santschi 1936
Pogonomyrmex (Ephebomyrmex) tenuipubens Santschi,
1936: 403, fig. 4 (worker). Syntypes examined: 1 worker [NHMB], #2055, ARGENTINA,
Misiones: Loreto (Dr. A. Ogloblin, 19 September 1933)
(NHMB worker here designated LECTOTYPE).
Ephebomyrmex tenuipubens (Santschi);
Kempf, 1972: 106. First combination
in Ephebomyrmex.
Pogonomyrmex tenuipubens Santschi; Lattke,
1991: 305. Revived combination in Pogonomyrmex.
Worker
Diagnosis. Within the P. naegelii-group, the combination of:
(1) approximately 16-20 fine, weak
longitudinal rugae between frontal lobes, (2) hairs
on head (including psammophore) and mesosoma very short and delicate, maximal length similar to
width of cephalic interrugae uniquely characterize
this species.
Measurements
– lectotype. HL 1.19; HW 1.10; MOD 0.27; OMD 0.27; SL
0.78; PNW 0.77; HFL 1.07; ML 1.37; PW 0.35; PPW 0.50. Indices: SI 70.91; CI 92.44; OI 24.55; HFI
97.27.
Description. Head elongate
(CI = 92.44), widest just posterior to eye; posterior margin flat. Longitudinal cephalic rugae fine and dense, slightly wavy; approximately 16-20
fine 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 rugose,
rugae converging between posterior margin of eye and
vertex; vertex rugose. Cephalic interrugal
spaces moderately granulate, weakly shining.
Anterior margin of clypeus moderately concave, dorsal surface with
numerous very fine subparallel longitudinal rugae; lateral lobes of clypeus lacking small lobe that
projects from anterior margin of antennal fossa. Mandible with five teeth; mandibular
dorsum coarsely striated. Up to several
moderately long, curved, bristle-like, yellow-brown to brownish hairs project
from anterior margin of clypeus. MOD =
0.23x HL. Eyes in profile situated
anterior to middle of head, OMD = 1.00x MOD.
Antennal scapes moderately long (SI = 70.91),
failing to reach vertex by approximately 2.0x length of basal funicular
segment; entire scape strongly striate, dull. Basal flange of scape
flattened, moderately well developed with carinate
margin. Psammophore
poorly developed, consisting of numerous very short hairs scattered across ventral
side of head.
Mesosomal profile weakly
convex; all mesosomal surfaces with weak wavy to
irregular rugae or rugoreticulate. Metanotal suture
not impressed. Dorsum
and sides of pronotum with irregular rugae to rugoreticulate. Dorsum of mesonotum with irregular
transverse rugae, mesopleura
with irregular rugae angling posterodorsally;
dorsum of propodeum with wavy transverse rugae that traverse anteroventrally. Propodeum with
moderately long, bluntly tipped spines connected by well defined keel; spine
length approximately 0.5-0.6x distance between bases. Inferior propodeal
spines well-developed with acute tip, length approximately 0.6x
that of superior spines, width at base greater than length of superior spines;
inferior and superior spines connected by a weak ruga. Propodeal spiracles ovoid to circular. Interrugal spaces
on mesosoma moderately granulate, weakly shining. Legs weakly coriarious, weakly shining.
Petiolar peduncle about
0.7x as long as petiole, anteroventral
margin slightly convex near mid-point but lacking triangular process. In side view, petiolar
node asymmetrical with anterior surface shorter than posterior surface, apex of
node weakly rounded, anterior face meeting peduncle at right angle. In dorsal view, petiolar
node longer than wide, widest near middle, narrowing to rounded anterior
margin; maximal width of posterior face only slightly greater than distance
between tips of superior propodeal spines; dorsum and
sides with weak transverse to oblique rugae, interrugal spaces moderately granulate, weakly shining. Dorsum of postpetiole
convex in profile; robust in dorsal view, widest at or near posterior margin, margins
of posterior one-half mostly parallel, anterior one-half narrowing to broadly
rounded anterior margin, maximal width greater than length, dorsum and sides
moderately to strongly granulate-punctate, dull. Ventral process of postpetiole large, bulbous, height similar to dorsal
portion of postpetiole. First gastral
tergum smooth and strongly shining.
Very short,
thin, delicate, suberect, whitish pilosity
moderately abundant on head, mesosoma, petiole, and postpetiole, hairs rarely longer than width of cephalic interrugae; one very long hair on each frontal lobe, length
exceeding MOD. Moderately
abundant short appressed pilosity
on scape plus several longer suberect
hairs; abundant decumbent hairs on funicular segments. Legs with moderately abundant appressed setae; gastral terga with sparse appressed,
thin, delicate hairs that are longer than those on rest of body; posterior
margin of second gastral tergum
also with several long erect hairs that are equal to or longer than MOD. Concolorous tan to tannish-brown with darker brownish gaster.
Queen. Unknown.
Male. Unknown.
Additional
material. PARAGUAY:
Caaguazú: Pastoreo (see Fowler,
1981; not examined).
Etymology: This
species was apparently named for the fairly abundant extremely short, fine
pubescence that Santschi noted to occur over most of
the body.
Discussion. Pogonomyrmex tenuipubens co-occurs
with both P. abdominalis
and P. naegelii. Pogonomyrmex tenuipubens can
be distinguished from these two species based on the following characters: (1) P. tenuipubens
has approximately 16-20 fine, weak longitudinal rugae
present between the frontal lobes, and (2) hairs on head (including psammophore) and mesosoma very
short, thin, delicate, their maximal length similar to width of cephalic interrugae. Both P. abdominalis
and P. naegelii
have approximately 8-10 coarse longitudinal rugae between
frontal lobes, and (2) hairs on head (including psammophore)
and mesosoma longer (usually >0.5x MOD) and
coarse, and their maximal length much longer than width of cephalic interrugae.
BIOLOGY
Pogonomyrmex tenuipubens appears to
be uncommon given the few times that it has been collected. Kusnezov and RAJ searched
the type locality, with both authors finding numerous colonies of P. naegelii but
none of P. tenuipubens. Nothing is known about the biology of P. tenuipubens,
but it is likely similar to that of P.
naegelii.
REFERENCES