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Camponotus
is a huge, worldwide genus of bewilderingcomplexity. Many species
are quite variable and most of the variants have been named, resulting
in a welter of inadequately described, poorly understood forms whose
relationships are often
obscured by superficial differences which have little or no taxonomic
value. This genus is an excellent example of taxonomic chaos.
Fortunately, the forms in the United
States are, for the most part, in a relatively stable taxonomic
condition. The group of species comprising the subgenus Myrmentoma,
was revised by Snelling (1988). We have but two species of Myrmentoma
in the desert and their separation presents no problems.
The remaining species are fairly easy
to separate. The key includes C. (Colobopsis) papago
Creighton, an arboreal species not known to occur in our area. Since
it has been taken in Arizona near the Colorado River it seemed well
to include it as a potential member of our fauna.
KEY
TO SPECIES OF CAMPONOTUS
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Workers
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| 1 |
Head of major, in profile, evenly arched from
clypeal apex to vertex, lower area not sharply contrastingly
sculptured
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2 |
| -- |
Head of major, in profile, obliquely truncate below, truncation
marginate and involving most of clypeus and adjacent side of
face, truncated portion vermiculate-rugose or reticulose, sharply
contrasting with sculpture elsewhere on head (subg. Colobopsis) |
papago Creighton* |
| 2
(1) |
Lower margin of median lobe of clypeus thickened, either transverse
or slightly convex and irregularly eroded or subdentate (Figs.
210, 212, 218) (subg. Tanaemyrmex)
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3 |
| -- |
Lower margin of median lobe of clypeus thin, weakly convex and
semicircularly depressed and incised in middle (Figs. 214, 216)
(subg. Myrmentoma) |
7 |
| 3
(2) |
Malar area without erect hairs or with no more than two or three;
lower margin of clypeus slightly convex, irregular; scape without
erect hairs except several tip
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4 |
| -- |
Malar area with 15+ erect hairs; median lobe of clypeus set
off on each side by distinct angulation, its ventral margin
transverse, even; scape with scattered erect hairs (Fig. 210) |
festinatus (Buckley) |
| 4(3)
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Metatibia usually not contrastingly darker than femur; median
carina of clypeus not terminating in blunt tooth; pronotum usually
with 10 or more erect hairs and node of petiole with five or
six on each side; scape usually flattened at base
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5
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| --��������
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Metatibia
blackish, contrasting with femur; median carina of clypeus ending
in blunt tooth; pronotum with fewer than ten, often no, erect
hairs and scale of petiole with no more than two or three, often
no, erect hairs on each side; scape not flattened at base (Fig.
212) |
ocreatus Emery |
| 5(4) |
Base of scape flattened, at least slightly broader
at base than immediately beyond; pubescence of T2 usually shorter
than distance between individual hairs
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6 |
| -- |
Scape narrowest at base, weakly flattened
(Fig. 220); discal pubescence of T2 longer than distance between
individual hairs
|
vicinus Mayr |
| 6(5) |
Margins of head of major, in frontal view, distinctly convergent
toward mandibular bases; scape with small lateral lobule at
base; apex of scape of major exceeding vertex corner by at least
its apical breadth (Fig. 219)
|
semitestaceus Snelling |
| -- |
Head
of major quadrate, margins strongly convergent immediately above
mandibular base; scape base broad, flattened, not lobulate;
apex of scape of major exceeding vertex corner, if at all, by
less than its apical breadth (Fig. 218)
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sansabeanus (Buckley)
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| 7(2)
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Metanotum, in profile, distinctly depressed below adjacent mesonotum
and propodeum; outer face of mandible with round punctures,
interspaces often polished; clypeus of major flattened and shiny
(Figs. 213, 214)
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hyatti Emery |
| -- |
Metanotum, in profile, little, if any, depressed; outer face
of mandible with elongate punctures, interspaces dull; clypeus
of major convex, dull (Figs. 215, 216) |
sayi Emery |
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females
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| 1 |
Head, in profile, evenly arched from
lower clypeal margin to vertex; lower portions neither vermiculate-rugose
nor reticulose .
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2 |
| -- |
Head, in profile, obliquely truncate
below, truncation marginate and involving most of clypeus and
adjacent sides of face and vermiculate-rugose or reticulose
(subg. Colobopsis) |
papago Creighton* |
| 2(1) |
Ventral margin of median lobe of clypeus
thickened, either transverse or slightly convex and irregularly
eroded or subdentate (subg. Tanaemyrmex)
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3
|
| -- |
Ventral margin of median lobe of clypeus
thin, weakly convex and semicircularly depressed and incised
in middle (subg. Myrmentoma) |
7 |
| 3(2) |
Malar area without erect hairs, or
with fewer than three; ventral margin of median lobe of clypeus
slightly convex and irregularly eroded |
4 |
| -- |
Malar area with 6-15 erect hairs;
median lobe of clypeus angulate at sides, ventral margin transverse;
scape with scattered erect hairs |
festinatus (Buckley) |
| 4(3) |
Median carina of clypeus, if present,
not terminating as dentiform process; base of scape flattened;
summit of petiole node usually entire; tibiae no darker than
femora
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5 |
| -- |
Median carina of clypeus terminating
in dentiform process; scape cylindrical at base; petiolar node
incised at summit; tibiae darker than femora |
ocreatus Emery |
| 5(4) |
Scape surpassing vertex corner by
more than length of A2; front of head contiguously micropunctate,
subgranulose, or finely and closely tessellate, punctures sparse,
fine and obscure; mesosomal side slightly to moderately shiny,
surface distinctly tessellate
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6
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| -- |
Scape surpassing vertex corner by
less than length of A2; front of head moderately shiny, with
sparse sharply defined small punctures and scattered coarse
punctures; mesosomal side shiny, surface weakly tessellate in
most areas |
sansabeanus (Buckley)
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| 6(5) |
Scape base flattened, with small
lateral lobule; front of head finely, densely tessellate, usually
not appearing granulose
|
semitestaceus
Snelling |
| -- |
Scape base flattened, without lobule; front of head contiguously
micropunctate, subgranulose
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vicinus
Mayr |
| 7(2) |
Head and mesosoma reddish; ocelli
large, IOD about 3 x OD, OOD no more than 4 x OD
|
sayi Emery |
| --
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Head and mesosoma brownish; ocelli small, IOD at least 4.5 x
OD, OOD about 6.5 x OD |
hyatti
Emery |
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