Pheidole heliosa Fischer, Hita Garcia &
Type location Ivory Coast
(Fischer, Hita Garcia & Peters, 2012: 12, Figures 42-47; major and
minor workers); vic.
Abidjan, 1976, no. 10 (T. Diomande) (BMNH: CASENT0227945).
Paratypes: (8 minor workers) same data as holotype (BMNH:
CASENT0227946, CASENT0227947, CASENT0227948, CASENT0227949) - no images
on Antweb (November 2014)..
Diagnosis: Pheidole heliosa
is the largest species in the P.
group, with a long alitrunk and a wide pronotum. Color orange, major
worker darker. Minor workers: head shape elongated, 1.25 times longer
than wide. Occipital carina strongly developed and relatively broad.
Scapes, legs and mandibles longest within the group, scape pilosity
subdecumbent to suberect. Highest number of standing hairs on head and
mesonotum within the group, also with laterally projecting hairs on
meso- and metapleuron. Second metanotal process long and pronounced,
postpetiole spheroidal in lateral view. Major worker: antennal scrobe
absent, head margin with laterally projecting hairs. Promesonotal dome
lower and longer than in other species of this group, in lateral view
almost continuous with mesonotal processes. Propodeal spines straight,
not curved posteriorly. Standing hairs abundant everywhere, including
on dorsopropodeum and laterally on meso- and metapleuron.
Description of minor
Measurements (n=8): HL 1.056–1.089
(1.074), HW 0.778–0.822 (0.798), SL 1.302–1.429 (1.353), MDL
0.639–0.800 (0.685), EL 0.167–0.200 (0.176), MFL 1.600–1.740 (1.678),
MTL 1.381–1.476 (1.427), WL 1.600–1.740 (1.678), PSL 0.294–0.400
(0.324), PTH 0.189–0.211 (0.198), PPH 0.233–0.278 (0.249), PTL
0.367–0.422 (0.385), PPL 0.267–0.283 (0.276), PTW 0.122–0.133
(0.128), PPW 0.261–0.300 (0.273), PW 0.567–0.611 (0.594); CI 73–76
(74), SI 162–174 (170), MDI 79–99 (86), PSLI 28–37 (30), PWI 73–76
(74), FI 206–213 (210), PpWI 200–232 (214), PpLI 129–152 (140).
Head about 1.25 times longer than wide, longest within group (CI
73–76), sides of head posterior of eye level elongated and converging
evenly towards posterior margin. Occipital carina conspicuous and
broad, almost collar-like. Mandibles very long (MDI 79–99), with
strong rugulae laterally, grading to smooth masticatory margin. Clypeus
smooth with short to inconspicuous lateral carinae. Face smooth,
hexagonally microsculptured, malar carinae interrupted, ending
posterior of eye level. Frontal carina developed but weak, ending at
eye-level, space near antennal insertion surrounded by conspicuous
carina. Scape long, longest within group (SI 162–174), in full face
view and when laid back, surpassing posterior margin by more than one
quarter to one third of its length, with subdecumbent to suberect
pilosity, about twice as long as scape diameter. Pronotum wide (PWI
73–76), outline in lateral view elongate convex, rounded towards
posterior declivity, smooth, only neck weakly punctured. Humeral area
laterally with short superficial carina, in dorsal view posterior of
highest point of pronotum lacking lateral pro- cess. Mesonotal
processes conspicuous and well-developed, second process almost as long
as first. Both processes, mesopleuron and propodeum weakly punctate.
Metanotal groove relatively narrow, conspicuously impressed,
dorsopropodeum with highest point immediately at metanotal groove,
weakly declining towards base of spines. Propodeal spines moderately
(PSLI 28–37), metafemur very long (FI 206–213), and metatibial
pilosity on inner edge subdecumbent, outer edge with longer suberect to
subdecumbent hairs. Petiole and postpetiole smooth dorsally, weakly
to superficially punctate ventrally. Postpetiole in lateral view
spheroidal and widest within pulchella
group (PpWI 200–232). Gaster smooth, hexagonally micropunctate.
Standing hairs very abundant,
slender and acute, of varying lengths, on mesonotum, propodeum and
waist segments relatively short, on mesosoma not restricted to dorsal
surfaces, also abundant lateroventrally (best visible in oblique
dorsolateral view). Colour yellow to light orange.
Description of major
Measurements (holotype): HL 2.450, HW
2.350, SL 1.238, MDL 1.300, EL 0.267, MFL 1.980, MTL 1.640, WL
2.100, PSL 0.272, PTH 0.422, PPH 0.544, PTL 0.611, PPL 0.422, PTW
0.311, PPW 0.700, PW 1.067; CI 96, SI 53, MDI 55, PSLI 11, PWI
45, FI 84, PeI 29, PpI 66, PpWI 225, PpLI 145.
Head longer than wide (CI 96), mostly rugose-punctate, with short
appressed to decumbent pubescence and in frontal view with several
laterally projecting hairs. Median ocellus developed, small. Mandible
relatively long (MDI 55). Median part of clypeus smooth, with
conspicuous median and several weak submedian carinae. Frons
longitudinally rugose-punctate, spaces in between weakly punctate,
rugae reaching posterior margin only at median emargination, grading
from weak to superficial rugulae on posterolateral lobes. Sides of head
laterally of frons rugose-reticulate, punctate, in full-face view with
several standing hairs projecting beyond lateral margin. Frontal
carinae inconspicuous and short, antennal scrobe absent to
inconspicuous. Promesonotum, in lateral view elongated and medially
raised, dorsally, antero- and dorsolaterally rugose-reticulate,
mediodorsally and posterolaterally mostly smooth with few short rugae
present. Humeri weakly vertically processed, sharply marginate and
rugose-reticulate. Mesonotal process uniquely shaped, broadly and
squarely raised above shallowly declining mesonotal declivity,
marginate and partly punctate, partly rugose-reticulate, and falling
steeply to a shallow, but extensively produced, medially flexed, and
posteriorly marginate second mesonotal process. Metanotal groove very
narrowly impressed in lateral view. Meso- and metapleuron weakly
punctate, with several weak to superficial irregular rugulae,
metapleural carinae very conspicuous, flange-like produced laterally.
In lateral view dorsopropodeum anterior to propodeal spines almost
level and about as long as spines, weakly punctate, laterodorsally very
densely punctate. Propodeal spines relatively short (PSLI 11), facing
almost straight up, not curved posteriorly. Posteropropodeum punctate,
partly overlain by superficial rugulae. Petiole laterodorsally and
ventrally densely punctate, smooth dorsal area on peduncle laterally
marginate. Postpetiole relatively wide compared to pronotal width (PpI:
66) and with strong ventral process, densely punctate, anterodorsally
with short longitudinal, on highest point with interrupted longer
transversal rugulae. First gastral tergite densely shagreened. Whole
body with abundant, long, slender filiform standing hairs of varying
lengths. Lateroventrally on pronotum and laterodorsally on propodeum
with abundant suberect hairs, best visible in dorsal view. Scape with
relatively short decumbent pilosity, metafemur with longer subdecumbent
pilosity. Colour of antennae, mesosoma, metasoma and occipital corners
reddish orange, rest of head darker.
species most similar to Pheidole
heliosa are P.
christinae and P. pulchella,
especially in color (yellow to orange).
All of them share the laterally projecting hairs on the head margin
anterior and posterior of eyelevel, which separates them from the
group of darkly colored species with laterally projecting hairs only
posterior of eye-level or completely without. Minor workers of P. christinae and P. pulchella
differ from P. heliosa in
shape of the promesonotum, in lateral and dorsal view (PWI 64–70 and
PWI 73–76), especially in the development of the second mesonotal
process, which in dorsal view is short and narrow [christinae] or
versus long and broad [heliosa].
pulchella differs from the other two orange coloured species in
scape and metafemur pilosity, which is short and decumbent [pulchella] versus
longer and subdecumbent to erect [christinae
and heliosa]. The P. heliosa type series was
collected in the Ivory Coast, additional
minor workers were from Cameroon and were found in sifted leaf-litter.
Additional material examined: CAMEROON: (1 minor worker) Prov. Sud
Ouest, Korup NP, 6.9 km 417° NW Mundemba, 19.iv.2000, 110 m, 05° 1.0'
N, 8° 51.8' E (B.L. Fisher).
Fischer, Hita Garcia & Peters (2012).