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Myrmecological News 23 139-152 Vienna, September 2016
Taxonomic updates for some confusing Micronesian species of Camponotus (Hymeno-
ptera: Formicidae: Formicinae)
Ronald M. C
LOUSE
, Benjamin D. B
LANCHARD
, Rebecca G
IBSON
, Ward C. W
HEELER
& Milan J
ANDA
Abstract
Indo-Pacific members of the speciose and morphologically confusing group of Camponotus ants that resemble C.
maculatus (F
ABRICIUS
, 1782) have recently been the subject of a molecular phylogeny, and that analysis is used here as
guidance to update the taxonomy of the Micronesian species. It is now known that Micronesian and some Melanesian
specimens previously identified as C. chloroticus E
MERY
, 1897 are not closely related to Polynesian, Fijian, and Melane-
sian specimens identified by the same name, and that the form on Palau presently identified as C. irritans kubaryi
M
AYR
, 1876 is not closely related to C. irritans (S
MITH
,
F., 1857). We therefore examined the morphologies of 185
specimens previously assembled for molecular analysis, plus five C. chloroticus and two C. kubaryi syntypes. Principal
component analyses were conducted to understand shape differences and match modern specimens to types. The
syntypes of C. chloroticus, which are from Tonga and southeastern New Guinea, matched the species that is today
represented by collections from Polynesia, Fiji, and Melanesia. Thus, specimens mostly from Micronesia and formerly
identified as C. chloroticus are here described as Camponotus micronesicus sp.n. In addition, C. kubaryi stat. rev. is re-
turned to species status, and Camponotus tol sp.n., a new species from the Micronesian island of Chuuk, is described.
Key words: Camponotus micronesicus sp.n., Camponotus tol sp.n., Camponotus kubaryi stat. rev., Camponotus chloro-
ticus, new species, Micronesia, Melanesia, Chuuk, Papua New Guinea, Pohnpei, Vanuatu.
Myrmecol. News 23: 139-152
ISSN 1994-4136 (print), ISSN 1997-3500 (online)
Received 4 February 2016; revision received 2 May 2016; accepted 12 May 2016
Subject Editor: John S. LaPolla
Ronald M. Clouse (contact author) & Ward C. Wheeler, Division of Invertebrate Zoology, American Museum of Natural
History, 200 Central Park West, New York, NY 10024, USA. E-mail: ronaldmclouse@gmail.com
Benjamin D. Blanchard, Committee on Evolutionary Biology, University of Chicago, 1025 E. 57
th
Street, Culver Hall 402,
Chicago, IL 60637, USA.
Rebecca Gibson, Department of Ecology, Evolution, and Environmental Biology, Columbia University, 10
th
Floor
Schermerhorn Extension, New York, NY 10027, USA.
Milan Janda, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05, České Budějovice, Czech Republic; La-
boratorio Nacional de Análisis y Síntesis Ecológica ENEM, UNAM, Antigua Carretera a Pátzcuaro 8701 Morelia, Mexico.
Introduction
A recent molecular analysis of 344 Camponotus speci-
mens, focusing on species similar to Camponotus macu-
latus (F
ABRICIUS
, 1782) in the Indo-Pacific, suggested
several novel relationships (C
LOUSE
& al. 2015). After
phylogenetic reconstruction, one unexpected result was that
the widespread species commonly identified as Campo-
notus chloroticus E
MERY
, 1897 in Micronesia is not close-
ly related to specimens referred to by the same name in
Polynesia and Fiji, and these two unrelated forms are
sympatric in Melanesia. (Fiji is often described as part of
Melanesia but is more accurately described as an "archi-
pelago located between Melanesia and Polynesia" (S
AR
-
NAT
&
E
CONOMO
2012).) The molecular analysis also
indicated that three other forms in Micronesia are distinct
species: Camponotus eperiamorum C
LOUSE
, 2007b from
Pohnpei Island, an unidentified species on Tol Island in
Chuuk State, and Camponotus kubaryi M
AYR
, 1876 stat.
rev. in Palau (a subspecies of Camponotus irritans prior
to this study) (Figs. 1, 2).
Given that what has been called "Camponotus chloro-
ticus" across the Pacific is actually two species, the first
question is which of the two forms is the true C. chloro-
ticus, and which needs to be described. Correctly identi-
fying specimens that generally resemble C. chloroticus is
important not only for the accuracy of faunistic surveys
but also for understanding their behavior and ecology,
which at present appears to be as similar as the morphol-
ogy. It has been reported that both C. micronesicus sp.n.
and C. chloroticus prefer coastal habitat (C
LOUSE
2007a;
S
ARNAT
&
E
CONOMO
2012), which is commonly disturbed
by humans and storms, and a preference for secondary
habitat has been demonstrated for at least one of these
forms in New Guinea (K
LIMES
& M
C
A
RTHUR
2014). How-
ever, it is also likely that at least where they are sympat-
140
Figs. 1 - 2: Clades IV (1) and V
(2) from the molecular phylogeny
of C
LOUSE
& al. (2015), high-
lighting the species examined in
this paper. Collection localities on
the maps are for specimens in the
molecular phylogeny used in the
morphological analyses here. Col-
ors match between branches in the
phylogeny, species labels, and lo-
cality markers, and the localities
of Camponotus chloroticus type
specimens are shown by stars.
Collection localities of all termi-
nals in the molecular phylogeny
can be seen in C
LOUSE
& al.
(2015).
ric they partition resources in subtle ways rather than
directly compete.
The best preserved specimen among the Camponotus
chloroticus syntypes is from Irupara, New Guinea (10° 4'
36.48" S, 147° 42' 39.96" E), southeast of Port Moresby,
on the southeastern end of the island. This locality puts it
inside the range of the clade of "C. chloroticus" specimens
found in Melanesia, Fiji, and Polynesia (Fig. 1). However,
the clade of mostly Micronesian "C. chloroticus" extends
to Vanuatu and Papua New Guinea as well (Fig. 2), so
the type from Melanesia could be either species. Only a
detailed morphological examination can resolve which of
these two species that have been called C. chloroticus
match with the C. chloroticus syntypes, or, in fact, whether
the syntypes are actually specimens of C. novaehollandiae
M
AYR
, 1870 or C. humilior F
OREL
, 1902, which also ex-
tend into New Guinea.
The types of Camponotus kubaryi stat. rev. and the
modern Palauan specimens in our molecular phylogeny are
large- and dark-headed forms that roughly resemble each
other and the specimen discussed in C
LOUSE
(2007a) under
the species code "Camponotus sp. 1945". In the molecular
phylogeny, C. irritans was represented by a single COI
sequence in the BOLD database (R
ATNASINGHAM
&
H
E
-
BERT
2007) from a specimen collected in India and identi-
fied as such; this sequence was 20% different from the two
Palauan specimens of C. kubaryi stat. rev. in our phylo-
geny. Moreover, the Palauan specimens were recovered
on a long branch among other Micronesian forms, away
from not only the one identified C. irritans specimen in
the analysis, but also the many unidentified specimens from
across Southeast Asia and the Indo-Pacific. Therefore, our
goal with this form was to determine whether modern Pa-
lauan collections in the molecular phylogeny and types of
141
Tab. 1: Definitions of measurements.
Name
Abbr.
Description
Eye length
EL
Dorsal
-
ventral distance in lateral view
Eye width
EW
Anterior
-
posterior
distance in lateral view
Forecoxa length
FCL
Length down middle in lateral view
Head length
HL
Distance from mid
-
vertex to anterior edge of clypeus in frontal view
Head width
HW
Distance across imaginary line through middle of the eyes, including the ey
es, in frontal view
Scape length
SL
Distance from antennal insertion to distal end in frontal view
Mesosoma length
ML
Weber's distance (distance from anterior pronotum to posterior propodeum, in lateral view)
Midtibia length
MTL
Total length measured do
wn middle
Petiole height
PH
Maximum height of petiole, seen in lateral view, orthogonal to PL
Petiole length
PL
Distance from anterior articulation with alitrunk to posterior articulation with gaster
Cephalix index
CI
(HW × 100) / HL
Scape index
SI
(S
L × 100) / HW
C. kubaryi stat. rev. are the same species, and subsequently,
since this lineage showed no close relationship with spe-
cimens identified as C. irritans in the molecular phylo-
geny, to decide if the morphological evidence supported
returning it to species status.
Thus, guided by the molecular phylogeny of C
LOUSE
& al. (2015), and with the aim of clarifying and updating
the taxonomy of the Camponotus maculatus-like species
in Micronesia, we analyzed a morphological data set col-
lected from the same specimens assembled for the mole-
cular phylogeny, as well as type specimens.
Material and methods
We examined the morphologies of 75 majors and 110 mi-
nors assembled for the molecular analysis, five syntypes
of Camponotus chloroticus, and two syntypes of C. ku-
baryi. There were 54 cases of a major associated with a
minor (on the same pin or part of a colony series). Many
of these specimens were successfully sequenced, constitut-
ing 103 terminals in the molecular phylogeny of C
LOUSE
&
al. (2015) (details available in Table S1, as digital supple-
mentary material to this article, at the journal's web pages).
Majors and minors had the same ten measurements re-
corded, which were chosen based upon their taxonomic
promise after preliminary examinations, and which are de-
fined in Table 1. We also used two standard indices made
from these data, Cephalic Index (the width to length ratio
of the head) and Scape Index (the ratio of the scape length
to the head width). The indices are reported but were not
used in principal component analysis (PCA) so as to not
overweight their constituent measurements in the analysis.
We also noted various discrete characters, including
coloration and pilosity. These latter characters are consid-
ered labile in ants, but they have been shown to be dia-
gnostic in the genus, which lacks many character options
overall. For example, Camponotus eperiamorum on Pohn-
pei Island is distinguished from C. micronesicus sp.n. (which
is on the same island) almost entirely by the former's bi-
colorous body and lack of long hairs along the side of the
head (C
LOUSE
2007b). These small morphological differ-
ences disguise the fact that the two species are very dis-
tantly related, as is now known from the molecular phylo-
geny (C
LOUSE
& al. 2015).
PCA is often used to explore multivariate data for
patterns that may correlate with data categories. Data are
transformed into variables ("principal components") that
are uncorrelated linearly, account for different percent-
ages of the total variation in the original values, and are
composed of different weightings ("loadings") of the ori-
ginal values. With morphological data, PCA can be used to
test for subtle shape differences between castes, popula-
tions, or putative species (recent examples from ants in-
clude G
RÜTER
& al.
2012,
Y
ATES
&
al.
2014). We thus used
PCA to ask whether the type specimens of Camponotus
choloroticus and C. kubaryi stat. rev. were similarly shaped
as modern specimens suspected of being the same species.
Principal component analysis (PCA) requires all measure-
ments to be available for each vector calculation, so for
terminals without one or the other caste, values were extra-
polated using simple linear models built by correlating the
same measurement (e.g., head width) between all paired
majors and minors in the dataset. PCAs were performed
in R using the "princomp" command. We show the rela-
tionship between the first and second principal compo-
nents for those specimens that represent the species of
special interest here: C. chloroticus, C. micronesicus sp.n.,
C. kubaryi stat. rev., C. novaehollandiae, and C. humilior.
One PCA analysis used major-minor pairs with missing
data replaced by extrapolated values, and the other PCA
analyses were done on majors and minors separately, us-
ing only observed measurements.
Except where otherwise noted (i.e., images from AntWeb.
org), color photographs were taken with a JVC KY-F70B
digital camera (www.pro.jvc.com) mounted on a Leica
MZ 12.5 stereomicroscope (www.leica-microsystems.com).
Images were captured at different focal planes and sub-
sequently combined using the application Auto-Montage
Pro Version 5.00.0271 by Syncroscopy (www.syncroscopy.
com). Measurements were taken using microscopes at Har-
vard University and the American Museum of Natural
History, using a reticle in one of the eyepieces and a conver-
sion table for each magnification, or were taken from photo-
142
Figs. 3 - 7: Relationships between Principal Components 1 and 2 for the Principal Component Analysis of morpho-
logical measurements taken from specimens in the molecular phylogeny of C
LOUSE
& al. (2015) and types for the
species of interest in this study. Figure 3 shows all species together, with missing measurements (including in cases
when minor or major specimens are not associated), and figures 4 and 5 show magnified views of the same scatterplot,
with some species removed. Figures 6 and 7 show majors and minors separately, without missing data extrapolated.
graphs with scale bars. Figures 1 - 35 were made in Adobe
Photoshop v. 12.0 and Illustrator v. 15.0.0 (Adobe Sys-
tems, Mountain View, CA).
Results
In all PCAs, the first component was responsible for the
bulk of the variance, and our different measurements con-
tributed fairly equally to this component. For the com-
bined analysis of major and minor workers, with missing
values replaced by extrapolated ones, the first component
of the PCA analysis accounted for 89% of the variance
(Figs. 3 - 5, 8). The loadings for the measurements con-
tributing to this component were nearly equal; 18 out of
20 loadings were between -0.21 and -0.24, and the smal-
lest two were -0.20 (petiole height of the minors) and
-0.16 (head width of the minors). These results were simi-
lar for the PCAs of the majors and minors independently.
For the majors, the first component accounted for 91% of
the variance (Figs. 6, 9), and loadings of the measure-
ments for this component ranged between -0.31 and -0.33.
For the minors, the first component accounted for 84% of
the variance (Figs. 7, 10), and the loadings ranged from
143
Figs. 8 - 10: Simplified representation of the PCA plots
shown in Figs. 3 - 7, with the total area covered by indi-
vidual points colored as single blocks. Figure 8 shows all
species together, with missing measurements (including in
cases when minor or major specimens are not associated),
and figures 9 and 10 show majors and minors separately,
without missing data extrapolated.
-0.30 and -0.34, except for head width (-0.24). The second
component added between 3% (majors and minors to-
gether and just majors) and 6% (just minors) to the cumu-
lative explanation of the variance.
In scatterplots between the first and second compo-
nents, Polynesian, Fijian, and Melanesian Camponotus
chloroticus specimens clustered with the C. chloroticus syn-
types, and Micronesian and Melanesian C. micronesicus
sp.n. specimens formed another cluster that overlapped
little with the C. chloroticus syntypes. This was true for the
combined analysis of major and minor workers (Figs. 3 -
5, 8), and majors and minors separately (Figs. 6, 7, 9,
10). Our PCA analyses also recovered C. kubaryi stat. rev.
as similar in shape to many C. novaehollandiae and C.
micronesicus, but molecular analyses recover it as not close-
ly related to either of these species. The C. kubaryi stat.
rev. syntype of a major worker matched the specimens
resembling this species in the molecular phylogeny (ter-
minal names PAL.2.CAM.Babeldoab and PAL.3.CAM.
Mecherchar), but the minor syntype that was mounted
well enough for measuring (see AntWeb.org, CASENT-
0904014) is large for a minor, clearly falling between the
other minor syntype and the majors in size (Tab. 2). None-
theless, the coloration, pilosity and head shapes of the syn-
types and other large, dark-headed Camponotus collected
from Palau suggest these specimens represent a single, if
variable, species. The head shapes of majors seem most
variable in the concavity of the vertex and degree of tap-
ering toward the mandibles (Figs. 11, 12, 14), but for
Camponotus this amount of variation is not uncommon.
We were able to discern some consistent morpholo-
gical differences between Camponotus micronesicus sp.n.
and C. chloroticus. Specimens of C. micronesicus sp.n.
are slightly more concave at the vertex and have longer
scapes than C. chloroticus, especially among the minors:
the Scape Index (ratio of the scape length to the head width)
for C. micronesicus sp.n. was measured at a minimum of
175 in minors, which is larger than the maximum SI meas-
ured for C. chloroticus minors (154; Tab. 2). Perhaps the
most reliable and easily seen character is that C. chloro-
ticus specimens have distinct standing hairs on the lower,
proximal hind femur and on the propleuron, and these are
absent in C. micronesicus sp.n. (Clade V, Fig. 2). These
hairs are in fact almost always present on the new species
from Chuuk, C. kubaryi stat. rev. from Palau, and C. eperi-
amorum on Pohnpei; thus, they appear to be a synapo-
morphy of Clade IV in the molecular phylogeny (Fig. 1).
Interestingly, in Emery's description of C. chloroticus,
based on types from Polynesia and Melanesia, he notes
(E
MERY
1897) that the hairs are close to those of C. kuba-
ryi. Propleuron and hind femurs hairs are distinct on the
Tongan syntypes for C. chloroticus, and on most of the
C. kubaryi stat. rev. types, but the New Guinean syntype
for C. chloroticus is mounted such that the hind femur
hairs cannot be seen, and the propleuron appears smooth
(Figs. 17 - 20).
In summary, it was already clear from the molecular
phylogeny of C
LOUSE
& al. (2015) that Polynesian, Fiji-
an, and some Melanesian specimens that looked like Cam-
ponotus chloroticus are a distinct species that is genetic-
ally distant from similar-looking specimens in Microne-
sia, as well as the morphologically variable species C.
humilior and C. novaehollandiae (which are found mostly
in Australia and New Guinea). Therefore, the key ques-
tion was whether the type specimens of C. chloroticus
and Polynesian, Fijian, and Melanesian specimens in the
molecular phylogeny tentatively identified as C. chloroti-
cus, besides sharing their ranges in Polynesia and New
Guinea, have morphological characters that also overlap.
We found that besides having similar morphometric char-
acters, the Polynesian syntypes of C. chloroticus and mod-
ern specimens have the same pilosity (standing hairs on
the hind femur and propleuron), which in fact distinguishes
the whole of Clade IV in the molecular phylogeny (Fig. 1).
The C. chloroticus syntype from Irupara is difficult to con-
nect to either species, for its shape is intermediate, and its
diagnostic pilosity is difficult to see; however, its short
scapes and wide head appear to ally it with the Tongan
syntypes more than the Micronesian specimens.
The molecular phylogeny also showed that specimens
from Palau that have been treated as a subspecies of Cam-
ponotus irritans are in fact not a color morph of any named
species, especially not C. irritans, a specimen of which
was recovered in the molecular phylogeny far from the
Palauan ones. The key morphological question with the
Palauan specimens has been whether they were close
enough to the type specimens of C. kubaryi stat. rev. to
be considered the same species. Their overall similar ap-
pearance and shared small island home inclines one to favor
144
Tab. 2: Means and ranges of morphological measurements (in mm) of type specimens and, for C. chloroticus and C.
kubaryi stat. rev., modern specimens used in PCA analyses, for comparison to historical types.
C. micronesicus
sp.n.
C. chloroticus
C. kubaryi
stat. rev.
type specimens New Guinean
syntype
Tongan
syntypes
non-type specimens syntypes
non-type specimens
Avg.
Range
n
Avg.
Range
n
Avg.
Range
n
Avg.
Range
n
Majors
EL
0.50
0.45
-
0.55
9
0.51
0.49
0.48
-
0.51
2
0.48
0.40
-
0.50
20
0.56
0.60
0.60
-
0.60
2
EW
0.39
0.35
-
0.45
9
0.33
0.30
0.25
-
0.35
2
0.37
0.30
-
0.40
20
0.40
0.45
0.45
-
0.45
2
FCL
1.27
1.20
-
1.40
9
1.22
1.02
1.01
-
1.04
2
1.15
1.00
-
1.31
20
1.46
1.50
1.45
-
1.55
2
HL
2.33
2.15
-
2.50
9
2.36
2.23
2.15
-
2.32
2
2.21
1.85
-
2.40
20
2.56
2.85
2.75
-
2.95
2
HW
2.07
1.85
-
2.30
9
2.20
1.96
1.88
-
2.04
2
2.00
1.45
-
2.25
20
2.40
2.70
2.65
-
2.75
2
ML
2.84
2.65
-
3.00
9
2.61
2.65
2.57
-
2.73
2
2.70
2.38
-
2.85
20
3.16
3.45
3.35
-
3.55
2
MTL
1.69
1.55
-
1.80
9
1.66
1.50
1.44
-
1
.55
2
1.70
1.55
-
2.10
13
1.97
2.05
2.00
-
2.10
2
PH
0.78
0.60
-
0.90
8
0.76
0.67
0.59
-
0.75
2
0.75
0.60
-
0.81
16
0.73
1.08
1.05
-
1.10
2
PL
0.63
0.55
-
0.65
9
0.47
0.46
0.43
-
0.49
2
0.60
0.44
-
0.75
18
0.56
0.80
0.75
-
0.85
2
SL
1.85
1.70
-
1.95
9
1
.68
1.60
1.55
-
1.64
2
1.65
1.44
-
1.85
20
2.10
2.18
2.15
-
2.20
2
CI
89
86
-
92
9
93
88
–
2
90
78
-
96
20
94
95
93
-
96
2
SI
90
83
-
98
9
76
82
76
-
87
2
84
73
-
124
20
88
81
80
-
81
2
Minors
EL
0.42
0.40 - 0.45
8
0.39
0.38 - 0.40
2
0.4
3
0.38 - 0.55
18
0.46
0.45 1
EW
0.32
0.30
-
0.35
8
0.31
0.30
-
0.31
2
0.33
0.30
-
0.40
18
0.36
0.35
1
FCL
1.05
0.95
-
1.15
8
0.92
–
1
1.05
0.90
-
1.40
18
1.24
1.10
1
HL
1.50
1.35
-
1.65
8
1.61
1.57
-
1.64
2
1.66
1.55
-
2.10
17
1.82
1.60
1
HW
1.
07
1.00
-
1.15
8
1.20
1.18
-
1.23
2
1.29
1.20
-
1.60
17
1.50
1.20
1
ML
2.36
2.20
-
2.50
8
2.25
–
1
2.40
2.20
-
3.05
18
3.00
2.45
1
MTL
1.61
1.50
-
1.70
8
1.31
–
1
1.59
1.40
-
1.95
15
2.48
1.70
1
PH
0.59
0.55
-
0.65
6
0.55
–
1
0.63
0.50
-
0.75
15
0.84
0.70
1
PL
0.56
0.50
-
0.60
7
–
–
0
0.57
0.50
-
0.70
16
0.36
0.60
1
SL
1.96
1.75
-
2.10
8
1.54
1.45
-
1.63
2
1.83
1.60
-
2.45
18
2.02
2.00
1
CI
71
67
-
74
8
75
–
2
78
74
-
82
17
82
75
1
SI
183
175
-
191
8
128
123
-
133
2
143
129
-
154
17
13
4
167
1
this hypothesis, and we found no strong evidence against
it in our examination of their morphology.
Thus, the totality of molecular and morphological evid-
ence leads us to propose the following taxonomic updates.
We describe Micronesian and Melanesian specimens for-
merly identified as Camponotus chloroticus and falling
in Clade V of the molecular phylogeny as a new species,
C. micronesicus sp.n., including New Guinean and Va-
nuatan specimens that are separated by a clade of mor-
phologically and molecularly distinct Vanuatuan specimens.
We did not designate as a paratype the Philippine minor
specimen recovered in the C. micronesicus sp.n. clade
(PHIL.6.CAM. Panicuason), since it is distinctly larger and
darker than Micronesian specimens, and it was recovered
on a long branch in the molecular phylogeny. Hybridi-
zation, whether historic or ongoing, remains a plausible
explanation for some of the more confounding specimens
in Camponotus, includig the distinct Vanuatuan and Philip-
pine specimens. We also return C. kubaryi stat. rev. to
species status, and we here describe the new form col-
lected from Chuuk as Camponotus tol sp.n. Taxonomic
histories below are from B
OLTON
(1995) and W
ILSON
&
T
AYLOR
(1967).
Camponotus chloroticus E
MERY
, 1897
(Figs. 15 - 20; Tabs. 2, 3)
Camponotus maculatus ssp. chloroticus E
MERY
, 1897.
Combination in Camponotus (Myrmoturba), as Camponotus (Myr-
moturba) maculatus chlorotica var. chlorogaster: E
MERY
,
1914.
Camponotus (Myrmoturba) maculatus pallidus var. samoensis
S
ANTSCHI
, 1919, unavailable name. Homonym of Campo-
notus irritans samoensis (S
MITH
, 1857).
Camponotus (Myrmoturba) maculatus ssp. sanctae crucis M
ANN
,
1919.
Subspecies of Camponotus irritans: E
MERY
1920.
Combination in Camponotus (Tanaemyrmex): E
MERY
1925.
Subspecies of Camponotus irritans: K
ARAVAIEV
1933.
Raised to species: W
ILSON
&
T
AYLOR
1967.
Comments: Camponotus chloroticus was originally de-
scribed by E
MERY
(1897) as a subspecies of C. macula-
145
Figs. 11 - 16: Syntypes of Camponotus kubaryi stat. rev. (11 - 12; CASENT0904012 and CASENT0910153, from
www.AntWeb.org, photographs by Zach Lieberman), holotype of C. micronesicus sp.n. (13), specimen of C. kubaryi
stat. rev. collected from Peliliu Is. (14; CASENT0173088, from www.AntWeb.org, photograph by April Nobile), and
syntypes of C. chloroticus from New Guinea (15) and Tonga (16). Scale bar in Fig. 13 applicable to Figures 11 - 16.
Tab. 3: Caste and label trans-
criptions for the syntypes of
Camponotus chloroticus E
M
-
ERY
, 1897.
Pin 1
Pin 2
Pin 3
Pin 4
Caste
Major
2 Minors
Major
Major
Label 1 N. GUINEA MER.
IRUPARA
Agosto Otto. 1889
L. LOR
IA
Tonga
Mus. God Tonga
Mus. God Tonga-Ins.
Label 2 TYPUS SYNTYPUS
Camponotus
Chloroticus
(Emery, 1897)
SYNTYPUS
Camponotus
Chloroticus
(Emery, 1897)
SYNTYPUS
Camponotus
Chloroticus
(Emery, 1897)
Label 3 Museo Civico di Genova MUSEO GENOVA
coll. C. Emery
(dono 1925)
MUSEO
GENOVA
coll. C. Emery
(dono 1925)
MUSEO GENOVA
coll. C. Emery
(dono 1925)
Label 4 SYNTYPUS
Camponotus
chloroticus
(Emery, 1897)
Label 5 irritans Sm.
subsp.
chloroticus
Em.
Label 6 Camponotus
irritans F. Sm.
subsp. chloroticus Emery
n. subsp.
146
Figs. 17 - 20: Syntype of Camponotus chloroticus from New Guinea in frontal (17), lateral (18), and dorsal (19) views,
and the original locality label (20).
tus, as follows: "I bought from Godeffroy Museum [Ham-
burg, 1861 - 1885] specimens of this form from the Tonga
Islands and New Britain, under the name C. pallidus. …
For the shape of the various parts of the body, for the
pubescence, the very weak sculpture and the hairs, it is
very close to the C. Kubaryi, M
AYR
[specific epithet cap-
italized in original], particularly the oceanic specimens and
those from New Guinea. … Maximum size is 8 mm; red-
dish-yellow, dirt-like color; head darker and more red, ab-
domen more or less blackish in its rear."
We do not know which aspects of the pilosity E
MERY
noticed as being similar to that of Camponotus kubaryi
stat. rev., but the presence of standing hairs on the prox-
imal hind femur and on the propleuron in both species is
one of the few readily discernable synapomorphies of an
important clade of Camponotus in the Pacific and one of
the key characters used to distinguish C. chloroticus from
C. micronesicus. Using this pilosity character, overall sim-
ilarity in size, shape, and coloration, as well as our find-
ing of only one such yellow Camponotus species in the
same islands, we confirm here that the Tongan syntypes
of C. chloroticus (Figs. 15, 16) match the species in Clade
IV, which extends from New Guinea to Polynesia (Fig. 2).
The Camponotus chloroticus syntype from Irupara, New
Guinea (Figs. 17 - 20), is not as clearly aligned with the
Tongan syntypes or modern specimens from the Poly-
nesian, Fijian, and Melanesian clade, partially due to its
mounting, which limits our view of the important pilosity
characters. However, the New Guinean syntype has dis-
tinctly shorter scapes than almost all C. micronesicus sp.n.
specimens measured, measuring just at the lower limit of
the range, and producing a scape index for the New Gui-
nea syntype that is smaller than all C. micronesicus speci-
mens measured but within the range for C. chloroticus.
The petiole length of the New Guinean syntype is also
similar to that of C. chloroticus specimens, and altogether
we have more support for it being C. chloroticus than C.
micronesicus sp.n. Other options for the identity of the
New Guinean syntype include an undescribed from, or, if
it is truly missing the hind femur and propleuron standing
hairs, an oddly concolorous C. humilior (which tends to be
bicolorous); C. novaehollandiae is too large, also usually
bicolorous, and, from our PCA analysis, slightly different
in shape.
To the original description we add a summary of our
morphological observations of this species, combining syn-
types and modern specimens, as follows (also see Tabs.
2, 3). Majors: EL 0.48 (range 0.40 - 0.51), EW 0.36
(0.25 - 0.40), FCL 1.14 (1.00 - 1.31), HL 2.22 (1.85 -
2.40), HW 2.00 (1.45 - 2.25), ML 2.69 (2.38 - 2.85),
MTL 1.68 (1.44 - 2.10), PH 0.74 (0.59 - 0.81), PL 0.58
(0.43 - 0.75), SL 1.65 (1.44 - 1.85); CI 90 (78 - 95), SI 83
(73 - 124). Mesosoma light yellow, gaster same color as
mesosoma or slightly darker, head color usually darker than
mesosoma; head tapering, vertex usually slightly concave;
hind femur and propleuron with standing hairs. Minors:
EL 0.42 (0.38 - 0.55), EW 0.33 (0.30 - 0.40), FCL 1.04
(0.90 - 1.40), HL 1.66 (1.55 - 2.10), HW 1.28 (1.18 -
147
1.60), ML 2.39 (2.20 - 3.05), MTL 1.58 (1.31 - 1.95), PH
0.62 (0.50 - 0.75), PL 0.57 (0.50 - 0.70), SL 1.80 (1.45 -
2.45); CI 77 (74 - 82), SI 142 (123 - 154). Mesosoma
usually light yellow, gaster and head usually same color as
mesosoma or slightly darker; head tapering, vertex con-
vex and occipital carina present; hind femur and propleu-
ron with standing hairs.
Camponotus kubaryi stat. rev. M
AYR
,
1876
(Figs. 11, 12, 14; Tab. 2)
Combination in Camponotus (Myrmoturba): F
OREL
1914.
Combination in Camponotus (Tanaemyrmex): E
MERY
1925.
Subspecies of Camponotus maculatus: E
MERY
1896.
Subspecies of Camponotus irritans: E
MERY
1920, K
ARAVAIEV
1929.
Comments: M
AYR
'
S
(1876) description of this species
consists of a few lines that describe it as 7.5 - 9.5 mm
long, reddish-brown, and with a darker head, mandibles,
and antennae, plus some description of characters that do
little to distinguish it beyond being in the genus Campo-
notus. Although this species is restricted to the islands of
the Republic of Palau, which constitute an area of less than
500 km
2
over 800 km away from any major landmass, it
still shows noticeable morphological variation (for exam-
ple, the head shapes and colors of syntypes shown in
Figs. 11, 12). This may be due to the fact that the country
is comprised of over 200 small limestone islands, which
may divide this species into many somewhat isolated popu-
lations. Nonetheless, despite variation in tone and shade,
and the degree to which the head is tapered and the ver-
tex concave, it is the only Camponotus in Micronesia with
a large, dark head, and its restriction to Palau makes iden-
tification straightforward. Still, we add to the original de-
scription this summary from our morphological examina-
tions, combining syntypes and modern specimens. Majors:
EL 0.59 (range 0.56 - 0.60), EW 0.43 (0.40 - 0.45), FCL
1.49 (1.45 - 1.55), HL 2.75 (2.56 - 2.95), HW 2.60 (2.40 -
2.75), ML 3.35 (3.16 - 3.55), MTL 2.02 (1.97 - 2.10), PH
0.96 (0.73 - 1.10), PL 0.72 (0.56 - 0.85), SL 2.15 (2.10 -
2.20); CI 94 (93 - 96), SI 83 (80 - 88); mesosoma medium
yellow, head and gaster much darker, approaching black;
head tapering and vertex distinctly concave; standing hairs
present on propleuron and hind femur. Minors: EL 0.46
(0.45 - 0.46), EW 0.36 (0.35 - 0.36), FCL 1.17 (1.10 -
1.24), HL 1.71 (1.60 - 1.82), HW 1.35 (1.20 - 1.50), ML
2.73 (2.45 - 3.00), MTL 2.09 (1.70 - 2.48), PH 0.77 (0.70 -
0.84), PL 0.48 (0.36 - 0.60), SL 2.01 (2.00 - 2.02); CI 79
(75 - 82), SI 150 (134 - 167); mesosoma light yellow, head
and gaster much darker, approaching black; head tapering
and vertex convex.
These characters match those of three other specimens
not used in this study but described in C
LOUSE
(2007a) un-
der the species code "sp. 1945". One of the majors is shown
in Figure 14, and the specimens can now be securely iden-
tified as C. kubaryi stat. rev. The two majors had total
lengths of 8.2 and 7.9 mm, matching M
AYR
'
S
original de-
scription, and the following other measurements are very
similar to those of the specimens we examined here: HL
3.00, HW 2.83, SL 2.30, CI 94, and SI 81 for the larger
specimen, and HL 2.73, HW 2.63, SL 2.07, CI 96, and SI
87 for the smaller. Likewise, the minor specimen of "sp.
1945" is very similar to the ones here: HL 1.77, HW 1.33,
SL 1.77, CI 75, and SI 133.
Camponotus micronesicus sp.n. B
LANCHARD
&
C
LOUSE
(Figs. 21 - 29; Tab. 4)
Type material: Holotype major worker, Federated States
of Micronesia: Pohnpei Island, Nah Islet, 1 m a.s.l. (6º 51'
11.2" N, 158º 21' 16.3" E), 15.IX.2010, leg. R. Clouse and
P. Sharma. Paratypes (8 major workers, 8 minor work-
ers), detailed collection information provided in Table 4.
All specimens are deposited in the Museum of Compara-
tive Zoology, Harvard University, Massachusetts, USA.
Description of holotype major worker (Figs. 21 -
23): EL 0.55, EW 0.40, FCL 1.30, HL 2.50, HW 2.25,
ML 3.00, MTL 1.80, PH 0.85, PL 0.65, SL 1.95; CI 90,
SI 87.
Masticatory margin with six teeth that diminish in size
unevenly from the apical tooth; teeth 2 - 5 similar in size,
sixth tooth (not visible when mandibles closed) distinctly
smaller. Clypeus continuing anteriorly past mandibular in-
sertions one fourth its total height, then slightly convex.
Posterior margin of clypeus straight to slightly concave,
antennal insertions separated from clypeus by a distance
almost equal to the distance from nearest clypeal margin to
clypeal midpoint. Posterior head margin weakly concave
to nearly flat. In frontal view: eyes located halfway be-
tween posterior clypeal margin and vertex; inner eye mar-
gins halfway between frontal lobes and sides of head; eyes
not extending past lateral margin of head. Antennae 12-
segmented. Antennal scape reaching past the posterior mar-
gin of head by a distance 1 - 2 times the width of the
scape at its apex. Mesosoma in profile gently sloping from
anterior pronotum to dorsal propodeum, with slightly steep-
er propodeal declivity. Petiolar node sloping evenly up to
and down from its apex.
Color: Gaster and mesosoma uniformly yellow-orange,
the head ranging from slightly to considerably darker
orange-brown. Vertex to posterior frons and anterior front-
al lobes orange brown, anterior frons and clypeus yellow-
orange; central posterior head and frontal carina dark or-
ange brown. Mandibles dark reddish brown, lighter at in-
sertions, mandibular teeth black. Each gastral tergite with
hyaline margin along posterior fifth.
Pilosity: Layer of small, recumbent, light hairs all over
head. Longer, standing hairs numerous on front, back, and
sides of head, longer at vertex and more dense on clypeus.
From frontal view, area between eyes and frontal carina,
two rows of long, standing hairs extending from vertex to
mid-clypeus. Dorsal pronotum, mesonotum and vertex of
propodeal angle with long standing hairs. Propleuron stand-
ing hairs lacking. Each gastral tergite with 10 to 20 long
standing hairs encircling tergite immediately before hya-
line margin along posterior edge; 5 to 10 longer standing
hairs encircling tergite halfway between hyaline margin
and posterior edge of previous tergite. Hind femur stand-
ing hairs lacking.
Sculpturing: Head, mesosoma, and gaster surface glos-
sy; genae, clypeus, and mandibles weakly punctured.
Description of paratypes: Majors resembling holotype
in coloration and pilosity, mesosoma ranging from light
yellow to orange-yellow, heads sometimes distinctly darker
than mesosoma but not brown. Generally same size or
smaller than holotype (ML 2.65 - 3.00, HW 1.85 - 2.30),
with similar head shapes (CI 86 - 92). Relative scape lengths
more variable (SI 83 - 98). Minors approximately 15% -
148
Figs. 21 - 23: Holotype of Camponotus micronesicus sp.n.
in frontal (21), dorsal (22), and lateral (23) views.
20% smaller than majors (ML 2.2 - 2.5) but with much
narrower heads (CI 67 - 74) and proportionally longer,
more variable scapes (SI 175 - 191). Mesosoma colora-
tion more consistently light yellow with similar or only
slightly darker heads. Occipital carina always present.
Measurements of minor worker collected with holotype
and shown in Figs. 24 - 26: EL 0.40, EW 0.30, FCL 0.95,
HL 1.35, HW 1.00, ML 2.30, MTL 1.50, PH 0.51, PL
0.50, SL 1.85; CI 74, SI 185.
Differential diagnosis: In Micronesia there are four
closely related Camponotus species that resemble C. macu-
latus (characters for which are described and illustrated
in M
C
A
RTHUR
&
L
EYS
2006): C. micronesicus sp.n., C.
eperiamorum, C. kubaryi stat. rev., and C. tol sp.n. Of
these species, only C. micronesicus sp.n. is mostly con-
colorous yellow-orange, and with the other three species
Figs. 24 - 26: Paratype of Camponotus micronesicus sp.n.
collected with the holotype, in frontal (24), dorsal (25),
and lateral (26) views.
being island endemics, C. micronesicus sp.n. can be col-
lected alongside only one of them at a time (C
LOUSE
2007a). In Melanesia collections of C. micronesicus sp.n.
are near those of three other described C. maculatus-like
species: C. choloroticus, C. novaehollandiae, and C. hu-
milior. However, only the latter two share the lack of pro-
pleuron and hind femur standing hairs with C. microne-
sicus sp.n., and although uniformly yellow-orange speci-
mens of C. humilior and C. novaehollandiae are occa-
sionally seen, both species tend to be strongly bicolorous.
Moreover, the head length and width measurements for
both majors and minors of C. novaehollandiae are approx-
imately 25% larger than those of C. micronesicus sp.n.,
and we have no evidence that the ranges of these species
overlap exactly with C. micronesicus sp.n. (C. humilior
and C. novaehollandiae enter New Guinea only along the
149
Figs. 27 - 29: Frontal views of Camponotus micronesicus sp.n. types (collection details in Table 4): paratype FSM.13.
CAM.Yap (27), paratype FSM.4. CAM.Chuuk (28), and holotype FSM.10. CAM.Pohnpei (29).
Tab. 4: Camponotus micronesicus sp.n. types and closely related specimens from Melanesia. Specimens are identified
by their terminal name in C
LOUSE
& al. (2015), followed by original collection codes.
Specimen(s)
Collection Data
Holotype major,
FSM.10.CAM.Pohnpei, 832.CAM.2.1
Federated States of Micronesia: Pohnpei Island: Nah Islet (6º 51' 11.2" N, 158º 21' 16.3" E),
15.IX.2010, leg. R. Clouse and P. Sharma
Paratype minor,
FSM.10.CAM.Pohnpei, 832.CAM.2.1
Federated States of Micronesia: Pohnpei Island: Nah Islet (6º 51' 11.2" N, 158º 21' 16.3" E),
15.IX.2010, leg. R. Clouse and P. Sharma
Paratype major and minor,
FSM.13.CAM.Yap, 845.CAM.1.1
Federated States of Micronesia: Yap Island, Mt. Madeqdeq at 159 m (9º 31' 32.5" N, 138º 6'
54.1"E), 23.IX.2010, leg. R. Clouse and P. Sharma
Paratype major and minor,
FSM.4.CAM.Chuuk, 813.CAM.2.1
Federated States of Micronesia: Chuuk, Tol Island at 120 m (7º 19' 27.3" N, 151º 36' 50.6" E),
8.IX.2010, leg. R. Clouse, P. Sharma, and Techuo family
Paratype major,
FSM.5.CAM.Chuuk, 813.CAM.3.1
Federated States of Micronesia: Chuuk, Tol Island at 120 m (7º 19' 27.3" N, 151º 36' 50.6" E),
8.IX.2010, leg. R. Clouse, P. Sharma, and Techuo family
Paratype major and minor,
FSM.6.CAM.Chuuk, 813.CAM.4.1
Federated States of Micronesia: Chuuk, Tol Island at 120 m (7º 19' 27.3" N, 151º 36' 50.6" E),
8.IX.2010, leg. R. Clouse, P. S
harma, and Techuo family
Paratype major and minor,
FSM.9.CAM.Pohnpei, 832.CAM.1.1
Federated States of Micronesia: Pohnpei Island, Nah Islet (6º 51' 11.2" N, 158º 21' 16.3" E),
15.IX.2010, leg. R. Clouse and P. Sharma
Paratype major and minor,
PAL.1.CAM.
Ngarchelong, 52761 & JCM0148a
Republic of Palau: Ngarchelong State, Ngarchor Island (7° 44.964' N, 134° 37.418' E),
3.V.2008, leg. J. Czekanski
-
Moir
Paratype major and minor,
PNG.9.CAM.Madang, 9335.1
Papua New Guinea: Lepa Island (5° 10' 48.0" S, 145° 49' 40.8" E), 6.XI.2010, leg. M. Janda
Paratype major and minor,
VAN.2.CAM, CR
-
111103
-
14
Vanuatu: Efate Is., 3 km west of Epao Village at 200 m (17° 36' 55.8" S, 168° 28' 27.3" E),
2.XI.2007, leg. C. Rabeling and E.O. Wilson
southern coast, where we have no C. micronesicus sp.n.
collections).
The most difficult cases of identification will be be-
tween Camponotus micronesicus sp.n. and C. chloroticus
specimens collected from Vanuatu, where they are sym-
patric and look nearly identical. Our best advice for iden-
tification is to check for hairs on the propleuron and hind
femur, which should be absent in C. micronesicus sp.n.
and present in C. chloroticus. In addition, C. chloroticus
minors usually have a larger cephalic index (74 - 82 vs. 67
- 74) and smaller scape index (123 - 154 vs. 175 - 191),
both resulting from having a wider head; majors show the
same trend, although those of C. chloroticus are highly
variable (Tab. 2).
Habitat: This species is found in disturbed forest, both
natural (e.g., reef islets, which are washed over during
heavy storms) and anthropogenic (e.g., agroforest at low
and middle elevations).
Etymology: This species is named for Micronesia, the
predominant region where it is found.
Comments: All paratypes are listed in Table 4 by their
terminal name in C
LOUSE
& al. (2015). A sample of some
of the variation in head shape of major workers from
across Micronesia is shown in Figures 27 - 29.
Camponotus tol sp.n. G
IBSON
&
C
LOUSE
(Figs. 30 - 35)
Type material: Holotype major worker. Federated States
of Micronesia: Chuuk, Tol Island at 120 m (7
o
19' 27.3"
N, 151
o
36' 50.6" E), leg. R. Clouse, P. Sharma, and Te-
chuo family. Paratypes, (3 major workers, 9 minor work-
ers), same collection data as holotype. Twelve additional
minors stored in 95% EtOH, as well as two minors each
150
Figs. 30 - 35: Holotype of Camponotus tol sp.n. in frontal (30), dorsal (31), and lateral (32) views, and minor paratype
from the same collection in frontal (33), dorsal (34), and lateral (35) views.
with one leg removed and used for DNA extraction, also
same collection data as holotype. All specimens are depo-
sited in the Museum of Comparative Zoology, Harvard
University, Massachusetts, USA.
Description of holotype major worker (Figs. 30 -
32): EL 0.48, EW 0.30, FCL 1.05, HL 2.05, HW 1.84, ML
2.51, MTL 1.54, PH 0.54, PL 0.60, SL 1.77; CI 90, SI 96.
Mandible outer margin gently curved to an apex of
about 75 degrees, the masticatory margin straight in front
view. Mandibles tightly closed, masticatory margin with
five visible teeth that gradually diminish in size from apex.
Clypeus continuing anteriorly past mandibular insertions
a distance slightly less than length of apical tooth, then
straight across. Posterior clypeus curved anteriorly form-
ing bilobed appearance, antennal insertions separated from
clypeus by a distance almost equal to the distance from
nearest clypeal margin to clypeal midpoint. Head slightly
longer than wide. Vertex weakly concave. In frontal view
eyes located halfway between posterior clypeal margin and
vertex; inner margins halfway between frontal lobes and
sides of head; eyes not extending past lateral edge. An-
tennae 12-segmented. Antennal scape length extending past
the vertex by a distance of 2 - 3 times the width of the
scape at the apex. Mesosoma in profile gently sloping from
anterior pronotum to dorsal propodeum, with moderate pro-
podeal declivity.
Color: Distinct bicoloration: head mostly glossy brown,
mesosoma uniform light yellow-brown, gaster glossy brown.
Gradual lightening from vertex down to mandibles. Vertex
to posterior clypeus same glossy brown as gaster. Black
151
outlining along frontal carina. Anterior clypeus to man-
dibular insertions light yellow-brown. Mandibles lighter
brown than vertex down to posterior clypeus. Teeth of
mandibles, scrobes, sutures, and joints on the head darker
than surrounding cuticle. Each gastral tergite with hyaline
margin along posterior fifth.
Pilosity: Layer of short, recumbent, light hairs all over
head. Long, yellow, standing hairs numerous on front,
back, and sides of head. In frontal view, area between
eyes and frontal carina with two rows of long, standing
hairs extending from vertex to mid-clypeus. Row of long
hairs extending across anterior clypeal edge. From dorsal
view, mesosoma with two side-by-side groups of standing
hairs on pronotum, four long hairs with some small hairs
per group; one group of standing hairs on mesonotum,
with three long hairs and some small hairs; two groups of
standing hairs clustered on propodeum, with three long
hairs per group; layer of short recumbent hairs all over each
appendage, decreasing in length from trochanter to tarsus.
Propleuron standing hairs indistinct but present. Each gas-
tral tergite with 20 to 30 long, yellow, standing hairs en-
circling tergite immediately before hyaline margin along
posterior edge; 10 to 20 longer standing hairs encircling
tergite halfway between hyaline margin and posterior edge
of previous tergite. Standing hairs on hind femur indis-
tinct but present.
Sculpturing: Head and gaster surface glossy; genae
weakly punctured. Mesosoma surface smooth and shiny,
although not glossy.
Description of paratypes: Majors closely resembling
holotype except vertex and mandibles more reddish-brown;
overall slightly larger (ML 2.6 - 2.75 and HW 1.88 -
1.95); CI same (90) but SI smaller (87 - 92), indicating
consistency in head shape and scape absolute length in
larger specimens. Minors closely resembling majors in
coloration and pilosity. Slightly smaller than majors (ML
2.00 - 2.25) and with significantly narrower heads and
longer, more variable scapes (CI 76 - 80, SI 157 - 172).
Scapes extending beyond vertex by a range of 25% - 50%
of total scape length. Posterior clypeus lighter brown than
holotype. Eyes extending past lateral outline of head. One
minor with open mandibles has six visible teeth on mas-
ticatory margin that gradually diminish in size from the
apex. Measurements of minor collected with holotype and
pictured in Figures 33 - 35: EL 0.45, EW 0.33, FCL 0.82,
HL 1.34, HW 1.05, ML 2.08, MTL 1.31, PH 0.45, PL
0.45, SL 1.73; CI 78, SI 165.
Differential diagnosis: The only specimens from Chuuk
that might be mistaken for Camponotus tol sp.n. are very
dark, small C. micronesicus sp.n., but C. tol sp.n. has
hairs on the propleuron and hind femur, and C. microne-
sicus sp.n. does not. Among other similar species in Mi-
cronesia, C. tol sp.n. is not as starkly bicolorous as C.
eperiamorum, and it is approximately 75% the overall
size of C. kubaryi stat. rev.
Habitat: This species was collected from low-elevation,
mixed agroforest (120 m a.s.l.) on Tol Island in Chuuk
Lagoon. This island is the largest in the region, and reaches
a maximum elevation of 439 m, but it shows evidence of
agroforesty and agro-native mixed forest at all elevations.
Specimens were collected from one colony and appeared
to be less abundant on the island than Camponotus micro-
nesicus sp.n.
Etymology: The specific epithet is a noun in apposi-
tion to the genus that refers to the type locality, Tol Is-
land (pronounced "tōl," as in the common word "toll").
Tol is the largest island inside the main atoll and island
group of Chuuk State in the Federated States of Micro-
nesia. The island is sometimes written as "Ton," as the
phonemes "l" and "n" are not distinct in Chuukese.
Comments: Camponotus tol is part of a larger clade
in the molecular phylogeny (Clade IV; Fig. 2) that in-
cludes C. chloroticus, C. kubaryi stat. rev., an undescribed
species collected in Papua New Guinea and Indonesia,
and an endemic species found on the nearby Micronesian
island of Pohnpei, C. eperiamorum (C
LOUSE
2007b, C
LOUSE
& al. 2015). These species are all larger than C. tol, and
they are also distinguished by their coloration: C. chloro-
ticus and the unnamed species are lighter, C. kubaryi stat.
rev. is darker, and C. eperiamorum contrasts more in shade
among the mesosoma, head, and gaster. All of these spe-
cies have the distinctive hairs on the propleuron and hind
femur, but only C. tol sp.n. has such a distinctive double
row of long hairs down the front of the head. Overall, C.
tol sp.n. is distinct as a dusky, small, member of the Cam-
ponotus maculatus-like species in the Pacific.
Discussion
We have used the results of a molecular study to guide us
in updating the taxonomies of a few members of one of
the most confusing groups of ants in the Indo-Pacific. Com-
bining those results with the morphological study here,
the Camponotus species that resemble C. maculatus in
Micronesia are now well understood. They consist of three
closely related island endemics (C. eperiamorum, C. kuba-
ryi stat. rev., and C. tol sp.n.) and one widespread spe-
cies, C. micronesicus sp.n. Nonetheless, even with a fresh
perspective on the relative utility of various morphological
characters in Camponotus, based on a broad sample of
specimens and a detailed examination, questions remain.
Most pressing is gaining a better understanding of what
forms are in Melanesia and to what degree the ranges of
C. chloroticus, C. micronesicus sp.n., C. humilior, and C.
novaehollandiae overlap. Our hypothesis that the syntype
from Irupara in New Guinea is indeed C. chloroticus is
worth testing with more samples from that area, and it
seems likely the large landmasses of Melanesia hold a num-
ber of taxonomic surprises in this group.
We advise that future work on Camponotus species
resembling C. maculatus begin with analyses of mole-
cular data, as reliance on morphological characters among
these species has led to many decades of taxonomic in-
stability and, in most cases, erroneous groupings. Never-
theless, as C. micronesicus sp.n. demonstrates, molecular
data do not provide the final answer, for the molecular
phylogeny placed some highly variant Vanuatan forms
within a clade we would otherwise readily consider this
species based on appearance. There is clearly a close rela-
tionship there, but the issue of hybridization in this group
is ripe for further investigation. We even retain some doubt
about specimens from New Guinea and the Philippines
tentatively considered here as C. micronesicus sp.n., the
latter of which we did not designate as a paratype. The
New Guinean specimens are nearly indistinguishable from
Micronesian ones but are separated in the molecular phy-
logeny by distinctly different looking Vanuatan specimens
152
(some of which are all black), and the Philippine speci-
men places confidently among C. micronesicus sp.n. in
the molecular phylogeny but has a very different size and
coloration.
Camponotus species that resemble C. maculatus are
common, highly visible members of the ant fauna in the
Pacific (unlike in Australia, where they are mostly noc-
turnal), and they may have utility as models of speciation
and convergence. It appears that understanding their di-
versity and relationships will be an iterative process, but
we have shown here that with ample sampling of speci-
mens and characters, advances can be made. We encour-
age field collections of this group whenever possible, as
well as continued rounds of molecular and morphological
analyses.
Acknowledgments
We thank the following funders for supporting this work:
DARPA (W911NF-05-1-0271), Marie Currie Fellowship
(PIOFGA2009-25448), Czech Science Foundation (P505/
12/2467), Putnam Expedition Grants (Museum of Com-
parative Zoology, Harvard University, Massachusetts, USA),
and the American Museum's Research Experience for Un-
dergraduates program (NSF). We are grateful to Stefan
Cover at the Museum of Comparative Zoology for assist-
ance with sampling mounted specimens. We are grateful to
the staff of the New Guinea Binatang Research Center for
field assistance, to V. Novotny, S.E. Miller and N. Pierce
for assistance with Papua New Guinea (PNG) projects, and
to the PNG Department of Environment and Conservation
for assistance with research permits. Research in Micro-
nesia was made possible through the assistance of Pra-
shant Sharma, the Chuuk Visitor's Bureau, the College of
Micronesia, the Conservation Society of Pohnpei, Yap State
Department of Resources and Development, the Belau Na-
tional Museum, and the University of Guam. Special field
assistance on the island of Tol (in Chuuk) was provided by
the Techuo family, and on Pohnpei Island by Amos Epe-
riam and Nixon Daniel. Alan Davis helped us understand
Chuukese place names, and Jim Carpenter assisted with
Latin names.
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