Global revision of the dulotic ant genus Polyergus (Hymenoptera: Formicidae, Formicinae, Formicini)
Author
Trager, James C.
text
Zootaxa
2013
3722
4
501
548
journal article
10.11646/zootaxa.3722.4.5
d2db5db0-c5ca-4150-8d74-d39f2d96a78f
1175-5326
249140
C1F59CA8-0F0E-471B-9B2D-26980A002511
Polyergus topoffi
new species
Figures 15, 16, 17
Polyergus rufescens
subsp.
breviceps
var.
montezuma
Wheeler 1914: 56
. Unavailable name; following material referred here:
MEXICO
, HIDALGO Pachuca [MCZ; 1 gyne,
3 workers
, and host
Formica
; red
syntype
label 9221] (examined, misspelled as “montezumia” on handwritten accompanying label); [USNM, 59726] (not examined; misspelled as “montezumia” in USNM
type
database).
Holotype
worker:
USA
, ARIZONA, Cochise Co., Portal. Topoff property, N31°
54.578 W
109°0 8.909 CWT068
1472 m
. Mesquite-Acacia thicket. JC Trager & CW Torres (MCZ)
Paratype
workers: Same data as
holotype
[MCZ, CAS, LACM]
Holotype
[ARIZONA, Cochise Co., as above] HL 1.62, HW 1.56, SL 1.22, ½ VeM 1, ½ PnM 9, WL 2.42, GL 2.40, HFL 1.80, CI 96, SI 78, HFI 115, FSI 148, LI 4.04, TL 6.44.
Paratypes
(N=5) [ARIZONA, Cochise Co., as above] HL 1.56–1.64 (1.60), HW 1.52–1.60 (1.54), SL 1.20– 1.24 (1.22), ½ VeM 0–1 (0.55),, ½ PnM 6–9 (7.20), WL 2.32–2.42 (2.39), GL 2.16–2.40 (2.24), HFL 1.72–1.80 (1.76), CI 95–98 (97), SI 75–82 (79), HFI 111–117 (1.14), FSI 139–148 (144), LI 3.88–4.04 (3.98), TL 6.12–6.44 (6.22).
montezuma
material (N=3) [MCZ] HL 1.48–1.60 (1.53), HW 1.50–1.53 (1.50), SL 1.20 (all 3), ½ VeM 0 (all 3),, ½ PnM 12–15 (13.67), WL 2.36 (all 3), GL 2.16–2.24 (2.20), HFL 1.64–1.72 (1.68), CI 96–100 (98), SI 78–81 (80), HFI 111–112 (1.12), FSI 137–143 (140), LI 3.84–3.9 (3.89), TL 6.08–6.12 (6.09).
Measurements, exclusive of
montezuma
syntypes
(N=31)) HL 1.48–1.68 (1.60), HW 1.40–1.64 (1.53), SL 1.16–1.28 (1.23), ½ VeM 0–1 (0.23), ½ PnM 4–9 (6.87), WL 2.16–2.52 (2.37), GL 1.84–2.56 (2.20), HFL 1.68– 1.88 (1.77), CI 93–100 (96), SI 75–86 (80), HFI 108–121 (116), FSI 139–155 (145), LI 3.68–4.20 (3.97), TL 5.54– 6.64 (6.16).
Worker description.
Superficially rather similar to
mexicanus
, but slightly more gracile, and nearly restricted to a Mexican distribution. Head nearly rectangular or quadrate, straight-sided anterior to eyes, with vertex corners rounded, HL usually a bit greater than HW; with vertex pilosity lacking or up to 2 setae; scapes not reaching vertex corners by about 1.5 maximum scape widths, notably clavate in the apical third; pronotum with 8–22 dorsal erect setae (but see
Discussion.
of
montezuma
“
types
”, below); mesonotum with profile flat or only slightly convex for most of its length, with a short posterior declivity; propodeum evenly rounded with dorsal and declivitous faces, especially in smaller workers, usually at>90o angle; petiole straight-sided above spiracles, sides parallel or only slightly converging dorsad, flowing seamlessly into the semicircular petiolar dorsum; first tergite densely pubescent, pubescence very fine; first tergite pilosity evenly distributed or slightly denser anteriad, some setae flexuous near front of tergite, but most weakly flexuous or straight, suberect.
Head matte to weakly shining; mesonotum matte to weakly shining, with scant pubescence; gaster matte to weakly shining beneath pubescence, shinier on sides.
Color mostly tannish-red with infuscation of posterior portions of tergites and slightly darker legs. Mesosomal pilosity usually notably darker than body color, gaster pilosity more reddish; pubescence short and yellowish gray. Only minor individual variation was detected among the Arizona specimens studied, and the Mexican
montezuma
differed only in somewhat more abundant pilosity, but fit perfectly in the middle of the measurement cloud of other specimens measured.
Discussion.
Of all the Nearctic species,
topoffi
is the one that most resembles Palearctic
rufescens
in sculpture, pilosity, head shape and appendage length. Where it overlaps with
mexicanus
in distribution, it is distinguished by a less shiny appearance and somewhat more tannish tinge to the base red color, longer scapes and legs, occurrence at lower elevations, and parasitism of different hosts. The scapes are longer than all other
breviceps
group species except
vinosus
. Wheeler’s unavailable variety
montezuma
, collected near Pachuca, Hidalgo,
Mexico
by
Mann
, belongs in this species, as it fits neatly within middle the range of metrics for Arizona
topoffi
(except with somewhat more abundant pilosity), and also comes from a subxeric, semi-open habitat. The three worker specimens of
montezuma
are more pilose than most Arizona specimens, with 22–26 macrosetae on the pronotum, and the three specimens each possess a few erect macrosetae lower on the sides of the pronotum. The
montezuma
sample is associated with the host species
F. subcyanea
.
Etymology.
I name this for Howard Topoff, who with his students has contributed so much to the modern literature on
Polyergus
, and in particular on this species. Howard also has a magnificent colony of this
Polyergus
near his house outside Portal AZ from which
holotype
specimen and
paratypes
were collected.
Natural history.
Polyergus topoffi
is relatively well-studied. Studies of a population in the vicinity of Portal, AZ, and at the Southwest Biological Research Station, just
5 miles
to the west, make this among the best studied of North American species. Colony foundation, sexual behavior, scouting and raiding of this species are documented in numerous publications by Howard Topoff and his students, under the name
Polyergus breviceps
(Topoff 1982, 1985, Topoff
et al
. 1984, 1985a, 1985b, 1988a, 1988b, 1989, Topoff and Greenberg 1988, Topoff 1990, Topoff and Mendez 1990, Topoff and Zimmerli 1993, Zimmerli and Topoff 1994), and even in National Geographic Society videos made with these authors’ cooperation, and at this writing, still occasionally aired on television nature programs. In the Chiricahua Mts. of AZ, the habitat of
topoffi
ranges from riparian desert scrub at
1450 m
, to the ecotone of oak-juniper and conifer forest around
1900 m
(and higher, in
Mexico
). It raids after the heat of the day, typically between 17:00 hr and dusk, robbing pupae from the host nests with little resistance and no mortality of the host workers, these known otherwise for their aggressive physical and chemical nest defense. Specimens of Wheeler’s
var.
montezuma
fit nicely, in metrics, color and surface texture, in the morphological concept of this species. Thus, subtropical, Madrean scrublands and oak woodlands of the Mexican highlands are another habitat of this ant.
Distribution of studied specimens.
ARIZONA Cochise Co. Chiricahua Mtns.
2.5km
292° Portal
31°55.92’N
10910.67’W ocotillo-opuntia rocky slope
1600m
4-14-VIII-2005
JT Longino (JTLC); ARIZONA Cochise Co. Chiricahua Mts. Cave Cr. Canyon
IX-10-1971
(LACM); ARIZONA Cochise Co. Chiricahua Mts. Cave Creek Canyon Idlewilde Cmpgr. Elev. 4950’ #1466
8/4/1988
; ARIZONA Cochise Co. S.W.R.S. 1995 Savolainen (1) 75/ 95; ARIZONA Cochise Co. Chiricahua Mts. Piney Canyon 5700’ Elev.
31°58.1’N
109°19.2’W
3.VIII.1991
#11 RA Johnson (RAJC); ARIZONA Cochise Co. Chiricahua Mts. SW Research Sta.
31°53.0’N
109°12.3’W
5400’ Elev.
9.VII.1993
#249 RA Johnson (RAJC); ARIZONA Cochise Co. Southwest Rsch. Section.
7-August-1986
H. Topoff P3, P5 (JCTC); SPCover (MCZ); ARIZONA Cochise Co. Chiricahua Mts. SWRS
5 m
.
W Portal Oak-Pine- Juniper Forest S of Station Elev. 5500’ SPCover #1472 (MCZ); ARIZONA Cochise Co. Chiricahua Mts.
6 m
.
W Portal
21-29 July
and (?)
Aug. 1983
M. Pagani; ARIZONA Cochise Co. Portal
July 3, 1956
#370 AC Cole (LACM); ARIZONA Cochise Co. Wilcox. Cochise Stronghold July 30,1954 #155,124,155 AC Cole (LACM); ARIZONA Gila Co. Jones Water Camp
14 July 1986
0 0 4 GC Snelling (JCTC); ARIZONA Cochise Co. Coronado NF Cave Creek Ranch 31.90300-109.13495±
5m
1491m
31.VIII.2011
Zach Lieberman (JCTC); ARIZONA Cochise Co. Chiricahua Mtns.
9.3km
W Portal
1900m
31.89956-109.23863±
200m
oak-pine-juniper woodland
10-VII-2011
Zach Lieberman (JCTC); ARIZONA Cochise Co. Chiricahua Mtns.
10.5km
W Portal E
Turkey
Creek 31.90882-109.25211±
200m
1960m
pine-oak forest/Douglas fir
10.VIII.2011
Zach Lieberman (JCTC); ARIZONA Gila Co. Mazatzal Mtns. Pigeon Springs
33°42.5’N
111°20.1’W
5600’ Elev. #112
22.v.1993
RA Johnson (RAJC); ARIZONA Santa Cruz Co. Patagonia Mts. 2000 Savolainen 12/00 (JCTC); ARIZONA Santa Cruz Co. Hershaw Creek
31°29.5’N
110°41.2’W
4550‘ Elev. #2207
26.VIII.1999
RA Johnson (RAJC);
MEXICO
. HIDALGO Pachuca. W. M.
Mann
.