Pheidole rebeccae Fischer, Hita Garcia &
Peters
  Type location Ivory Coast
(Fischer, Hita Garcia & Peters, 2012: 35, Figures 57-62); vic.
Abidjan, 1976, no. 15 (T. Diomande) (BMNH: CASENT0227954). Paratypes:
(3 major workers, 8 minor workers) same data as holotype (BMNH:
CASENT0227955, CASENT0227956, CASENT0227957, CASENT0227958) - no type images on Antweb (June 2015).  .
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Diagnosis:
Color reddish brown (major) to brown (minor). Minor workers: head shape
rounded, almost as broad as long (CI 94–98), posterior margin
compressed to almost straight. Scapes short (SI 114–121), pilosity
mostly decumbent. Most dorsal surfaces superficially punctate (sides of
head, propodeum, anterior gaster) to smooth and shiny (posterior head
margin, promesonotum, waist segments partly). Metafemur relatively
short (FI 133–139), metatibia pilosity decumbent. Major workers: head
and promesonotum with short and weak superficial rugulae, posteriorly
largely smooth and shiny. Sculpture on meso- and metapleuron also
reduced, with several smooth spots. Metanotal groove barely impressed
in lateral view and length of dorsopropodeum anterior to propodeal
spines equal to horizontal width of base of spine. Standing hairs
abundant, but absent from propodeum, sometimes also from rest of
alitrunk [mesosoma]. |
Description of major
worker:
Frons with relatively weak, irregular, very short or interrupted rugae,
spaces between rugae superficially punctate, only a narrow, sculptured
strip continuing towards median emargination of posterior margin.
Posterolateral lobes and sides of head posterior of eye-level smooth
and shiny, on most hexagonally microsculptured. Scape pilosity
appressed. Pronotum anteriorly weakly to superficially and transversely
rugulose-punctate and posteriorly smooth, or in some specimens with
superficial punctures and/or with weak to superficial rugulae. Humeri
with weak and subangulate lateral process, pronotal declivity rounded
to subangulate. Mesonotal process almost right-angled, second
mesonotal process inconspicuous, at most represented as weak,
quasi-vertical ridge. Metanotal groove forming broad constriction
between mesonotum and propodeum in dorsal view, shallow to unimpressed
in profile. Meso- and metapleuron weakly to superficially punctate,
with several smooth spots (extent of sculpture strongly varies with
viewing angle). In profile, dorsopropodeum anterior to propodeal spines
shorter than horizontal width of base of spine, in dorsal view
anteromedially smooth, lateraloventrally densely punctate, posteriorly
between spines transversely and weakly rugulose. Posteropropodeum
weakly and transversely rugose-punctate, laterally with vertical
curved rugae from spines towards metapleural carina(e). Metatibial
pilosity appressed. Anterior face of petiole broadly smooth and shiny,
rest of petiole and postpetiole densely punctate. Postpetiole with
short irregular rugulae posterodorsally and conspicuous lobate flange
posterolaterally. Gaster weakly punctate. Long standing hairs acute,
present everywhere, except on propodeum. Mesonotum with shorter
subdecumbent hairs and sometimes mesosoma completely without hairs
other than short appressed pubescence.
Measurements holotype: HL 1.960, HW 1.980, SL 0.978, MDL 0.911, EL
0.250, MFL 1.476, MTL 1.133, WL 1.556, PSL 0.278, PTH 0.333, PPH
0.411, PTL 0.556, PPL 0.344, PTW 0.239, PPW 0.522, PW 0.900
Indices: CI
101, SI 49, MDI 46, PSLI 14, PWI 45, FI 75, PeI 27, PpI 58,
PpWI 219, PpLI 161.
Measurements (n=3): HL 1.820–1.980 (1.900), HW 1.860–1.960 (1.927),
SL 0.944–0.967 (0.956), MDL 0.833–0.889 (0.859), EL 0.233–0.267
(0.256), MFL 1.476–1.556 (1.503), MTL 1.078–1.122 (1.104), WL
1.444–1.524 (1.487), PSL 0.244–0.300 (0.278), PTH 0.322–0.344
(0.337), PPH 0.361–0.400 (0.378), PTL 0.467–0.500 (0.489), PPL
0.311–0.356 (0.330), PTW 0.211–0.233 (0.226), PPW 0.456–10.533
(0.493), PW 0.856–0.900 (0.881)
Indices: CI 99–103 (102), SI 49–51 (50),
MDI 42–45 (44), PSLI 13–16 (15), PWI 45–46 (46), FI 75–84 (78),
PeI 25–26 (26), PpI 53–59 (56), PpWI 210–229 (218), PpLI 141–161
(149).
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Description of minor
worker: Head shape in full-face view compactly rounded,
posterior margin of
head compressed to almost straight. Occipital carina narrow, mandibles
relatively short (MDI 69–73). Clypeus smooth, with two very faint
median carinae, lateral carinae usually more strongly developed. Face
smooth and shiny with faint hexagonal microstructure. Malar carinae
short, ending at midlevel of eyes. Scapes relatively short, shortest
within group (SI 114–121), pilosity decumbent, partly subdecumbent to
suberect apically. Promesonotum smooth and shiny, without sculpture,
mostly without standing hairs, but occasionally with two pairs of long,
blunted hairs on anterior corners of humeral area or one pair on
humeri. Meso- and metapleuron weakly to superficially punctate,
katepisternum and anterior metapleuron with smooth central spots. First
mesonotal process conspicuous, roundly angulate. Second process reduced
to a shallow, obliquely angulate projection or ridge, metanotal groove
wide and deep. Dorsopropodeum weakly punctate, descending smoothly from
highest point after metanotal groove towards propodeal declivity.
Propodeal spines relatively short (PSLI 25–30) and slender, almost
straight to well-curved posteriorly. Metafemur relatively short,
shorter than in other species from this group (FI 133–139), metatibial
pilosity decumbent. Petiole and postpetiole weakly punctate laterally
and ventrally, dorsally smooth and shiny. Anterior half of first
gastral tergite shagreened, rest smooth, hexagonally microsculptured or
whole gaster weakly punctate. Long standing hairs often truncated,
present on head, postpetiole and gaster, number on dorsal head
variable, up to five pairs, absent to very scarce on mesosoma and
petiole, both usually with shorter decumbent hairs. Pubescence
inconspicuous, mostly fine and appressed. Color brown, mandibles and
appendages lighter.
Measurements (n=11): HL 0.756–0.811 (0.785), HW 0.717–0.778 (0.754),
SL 0.856–0.900 (0.885), MDL 0.511–0.556 (0.531), EL 0.167–0.178
(0.171), MFL 0.967–1.067 (1.024), MTL 0.756–0.867 (0.809), WL
1.011–1.078 (1.035), PSL 0.194–0.233 (0.217), PTH 0.167–0.178
(0.170), PPH 0.183–0.206 (0.194), PTL 0.267–0.333 (0.303), PPL
0.189–0.222 (0.197), PTW 0.106–0.111 (0.110), PPW 0.189–0.217
(0.204), PW 0.456–0.500 (0.475)
Indices: CI 94–98 (96), SI 114–121 (117),
MDI 69–73 (70), PSLI 25–30 (28), PWI 62–64 (63), FI 133–139 (136),
PpWI 170–195 (185), PpLI 133–176 (154).
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Discussion: Pheidole rebeccae
specimens were collected in the Ivory Coast and in Ghana. The minor
workers from Ghana differ slightly from those from the Ivory Coast in
the extent of sculpture on the first gastral tergite. Minor workers of P. rebeccae, in overall habitus and
reduced body sculpture, are closest to those of P. glabrella, and best
differentiated from the latter by wider head shape (CI: 94–98 [rebeccae] versus CI: 88–95 [glabrella]),
shorter scapes, propodeal spines and metafemur (SI 114–121, PSLI
25–30, FI 133–139 versus SI 123–141, PSLI 28–40, FI 143–170), and
more abundant standing hairs. Major workers of P. rebeccae
are distinctively separated from those of other species by the short
and weak longitudinal rugulae in face, largely smooth and shiny
surfaces on the posterior half of face and pronotum, and reduced
sculpture on meso- and metapleuron. Major workers of P. darwini
also feature a reduced punctate sculpture in face and on posterior
pronotum and partly smooth posterolateral lobes, but the longitudinal
rugae are longer and more conspicuous, the punctures between the rugae
are stronger, smooth surfaces on the head and mesosoma are restricted
to significantly smaller areas and promesonotal standing hairs are long
and erect versus shorter and decumbent in P. rebeccae. A unique character in P. darwini
is the small number of erect hairs in combination with the appressed to
decumbent pilosity along the outer edge of the scape, that is absent in
the majors of P. rebeccae.
Etymology: This species is named after the first author’s
daughter Rebecca.
Additional material examined: GHANA: (3 minor workers) Atewa Forest
Reserve, nr. Kibi, 26.ii.1992 (R. Belshaw).
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 Illustration from
Fischer, Hita Garcia & Peters (2012).
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Specimens in OUMNH Collection
Pheidole rebeccae
B Taylor det. |
Liberia
E Poirier
Yekepa
PF 6
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29.iii.2013
Nimba County
07°33’38" N
08°32’33" E
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Pitfall trap
Degraded secondary forest
518 m asl
minor
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2
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 The photomontage is of
a worker from Libera, Yekepa; collector E Poiriet
(Yekepa PF 6). Matches the overall characters of rebeccae but appears to be darker, although I suspect the main reason is the poor colour reproduction in the type publication.
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