Observaciones de pogolumina

Ft Huachuca historical marker pullout, Hwy 90, Huachuca City, AZ

Pheidole titanis (major and minor workers)

Nest with single, unadorned, circular entrance hole. At least 2 separate foraging columns made up mostly of minors, with the occasional major. The ants were moving quickly and were not in single file. At least one of the columns lead to a source of termite workers underneath twig, leaf, and dried grass-stem litter. In some of the photos Ph. titanis minors can be seen capturing the termite workers. Ph. titanis has long been considered to be a specialized predator of termites.

NOTE: The majors did not seem particularly gigantic, especially when compared to the minors. Creighton and Gregg address this in ‘New and Little-Known Species of Pheidole from the Southwestern United Sates and Northern Mexico (1955). There appears to be a rather large size range for major workers in this species. Creighton and Gregg mention specimens ranging from 4.5-5.0mm, 5.5-6.0 and 7.25-8.0mm depending on the series/colony. The 7.25-8.0mm figure is for the type specimens and explains why Wheeler chose the name Titanis.

Overcast, breezy
AIR TEMP: 23°C/73°F
ELEVATION: approx. 1350m/4430ft
DLQ LOC: A21222

AZ TRAIL/Pine Trailhead, Pine AZ (Gila County)

Sunny, breezy
AIR TEMP: 12.7-14°C/55-57°F
ELEVATION: approx. 1640m/5380ft

Pogonomyrmex occidentalis (workers)

Pine forest clearing. Large, low gravel nest mound about 0.9m/3ft in diameter with multiple entrances, and cleared peripheral area.
At 8:40 AM, nest in partial shade, with an air temp of 12.7°C/55°F, 5-6 workers were moving sluggishly on nest-mound surface. First maintenance activity observed at 9:35 AM (14°C/57°F) when a single worker removed a pebble from the nest interior.
There was another P. occidentalis nest about 49m/160ft away.

The distinctly offset/upturned basal mandibular tooth (diagnostic for this species) is clearly visible in these images.

DLQ LOC: A21219

Flagstaff, AZ – Rt 66 and Rain Valley RD

Sunny
TEMP: 23°C/77°F
ELEVATION: 2042 m / 6700 ft

Pogonomyrmex occidentalis - the western harvester ant

Recognizable by the long, slender propodeal spines, ‘beaded’ appearance of cephalic inter-rugal spaces, the offset (up-turned) basal mandibular tooth (see images 3 and 4), and the distinctive nest mound.

Grassy meadow - many nests in area – some were enormous with large peripheral clearings – visible to the east in the Google satellite imagery. This was the only one we had time to observe / image.

Gravel nest mound approx. 0.6m/2ft in diameter at the base, with single entrance at the eastern, bottom edge of mound (image 8). Virtually no peripheral clearing. The workers of this colony were on the small side for this species. Much activity – many workers out foraging miscellaneous plant parts and scavenging insect carcasses. It was already quite warm, so the workers were easily agitated. I was stung twice on the left arm while photographing activity near the nest entrance. Only very slight red marks were visible, but pain lasted for about 5 hrs.

At one point, a foraging Dorymyrmex sp. worker briefly approached the pogo nest entrance (image 2) and was challenged by a P. occidentalis worker for a few seconds. The intruder then left and continued foraging.

DLQ LOC: A20199

Madera Canyon (Madera Picnic Area)

Mostly cloudy (had rained in previous 24hrs)
TEMP: 23°C/74°F
ELEVATION: 1475 m / 4840 ft

Neivamyrmex sp.

Army ants of the genus Neivamyrmex (possibly N. nigrescens, N. texanus or N. rugulosus?).

Raiding/foraging column issuing from a single, unadorned hole and extending about 15 ft into thick leaf litter (Oak/Juniper forest). The ants did not appear to be finding any prey, with the exception of one alate female Trachymyrmex (there were Trachymyrmex sp.mating swarms in the area). At about 10:45 AM the ants funneled back into the hole and activity ceased.

DLQ LOC: A20198

Organ Pipe National Monument, AZ

Sunny
TEMP: 21°C/70°F
ELEVATION: approx. 784m/2572ft

Pogonomyrmex pima

Cryptic nest entrance under edge of small stone, with small (less than 5 cm/2 in) ‘apron’ of very fine soil. Several workers coming and going while performing nest maintenance. A few other individuals roaming father from the nest, but we did not observe any successful foraging.

These ants were differentiated from the very similar Pogonomyrmex imberbiculus by the lack of the prominent, forwardly directed projection in front of each antennal fossa that is present in imberbiculus. Also, the dorsal surface of the petiolar node not strongly rugo-reticulate, as in P. imberbiculus.

DLQ LOC: A20182

Organ Pipe National Monument, AZ

Sunny
TEMP: 21°C/70°F
ELEVATION: approx. 784m/2572ft

Pogonomyrmex bicolor

Approx. 25 cm/10 inch cleared area with sparse gravel, single entrance hole, but no mound (the external nest structure may have been eroded/destroyed by heavy rains which occurred in the preceding days). Lots of nest maintenance being performed by partially debris-covered workers. Many workers foraging – some of the foraged material appeared to be of the genus Eriastrum.

The ants did not react in any way to our presence.

DLQ LOC: A20183

Tom Mix Monument - near Florence AZ

Sunny
TEMP: 20°C/68°F
ELEVATION: approx. 718m/2355ft

Pogonomyrmex pima

Cryptic nest entrance. 5-6 workers performing nest maintenance and foraging.

These ants were differentiated from the very similar Pogonomyrmex imberbiculus by the lack of the prominent, forwardly directed projection in front of each antennal fossa that is present in imberbiculus. Also, the dorsal surface of the petiolar node not strongly rugo-reticulate, as in P. imberbiculus.

DLQ LOC: A20180

Tom Mix Monument - near Florence AZ

Sunny
TEMP: 20°C/68°F
ELEVATION: approx. 718m/2355ft

Pheidole spadonia

2-3 cryptic nest entrances, and an additional one with small disc of excavated soil – all within an area about 0.7 m/2.5 ft wide. It wasn’t clear if any/all of these were multiple entrances of one colony, or just 3-4 separate colonies. Wilson mentions a very similar nest arrangement on page 600 of ‘Pheidole in the New World.’

Many minor workers observed returning to one of the cryptic nest entrances with unidentified seeds. Only 2-3 major workers seen.

All of the morphological features used to ID this ant can be seen in the photos.

From Wilson - ‘Pheidole in the New World’ (can also be accessed on AntWiki):

Major: anterior half of head densely carinulate, with a few carinulae traveling along the dorsal midline all the way to the occiput, and the entire remainder of the body smooth and shiny; propodeal spines well-developed and vertical to the basal propodeal face; the petiolar node seen from the side tapering to a point; the postpetiole seen from above very broad, and spinose.

Minor: propodeal spines well-developed and vertical to basal propodeal face; almost all of the head and mesosoma smooth and shiny.

DLQ LOC:A20179

Tom Mix Monument - near Florence AZ

Pheidole xerophila

Sunny
TEMP: 19°C/66°F
ELEVATION: approx. 718m/2355ft

3 nest entrances with small discs of excavated soil. 2 of the ‘mounds’ partially ringed with chaff. Many minor workers engaging in nest maintenance and foraging. Unidentified seeds being retrieved. 3-4 major workers present outside of nest.

DLQ LOC: A20178

Tom Mix Monument - near Florence AZ

Sunny
TEMP: 17.7°C/64°F
ELEVATION: approx. 718m/2355ft

Acromyrmex versicolor

Small (approx. 15 cm/6 in diameter, 7 cm/2.75 in in height) gravel crater mound near mesquite tree. This was probably a ‘satellite’ nest entrance – there was most likely a larger primary nest crater hidden under the dense, spring growth of annuals.

Several minor and media workers observed engaging in nest maintenance.

DLQ LOC: A20176

Tom Mix Monument - near Florence AZ

Sunny
TEMP: 17.7°C/64°F
ELEVATION: approx. 718m/2355ft

Pogonomyrmex rugosus

Low gravel nest mound/crater approx. 35 cm/14 in diameter. Many workers loitering near nest entrance, or bringing excavated soil from nest interior.

DLQ LOC: A20175

Tom Mix Monument - near Florence AZ

Sunny
TEMP: 17.7°C/64°F
ELEVATION: approx. 718m/2355ft

Pogonomyrmex rugosus

Large, flat gravel disc with single (central) entrance hole. At least 50 workers ‘huddling’ near nest entrance when we first arrived. Some workers wandering a few meters away from the nest, but we did not observe any actual foraging. A worker managed to climb up under my shirt and deliver a very painful sting.

DLQ LOC: A20174

Tonto Nat’l Forest - Coon Bluff Rec Area

Sunny
TEMP: 21°C/70°F
ELEVATION: approx. 414m/1357ft

Pogonomyrmex pima

Approx. 7cm/2.75in nest disc of very fine soil, with single entrance near center (see image 5). Creosote scrub habitat.

Several workers were engaging in nest maintenance. It had rained heavily in the days before this observation was made – soil was still somewhat damp. No foraging activity was observed.

There was another similar P. pima nest about 2.5m/8.2ft due north.

These ants were differentiated from the very similar Pogonomyrmex imberbiculus by the lack of the prominent, forwardly directed projection in front of each antennal fossa that is present in imberbiculus. Also, the dorsal surface of the petiolar node not strongly rugo-reticulate, as in P. imberbiculus.

DLQ LOC: A20173

Catalina State Park

Sunny
AIR TEMP: 19.4°C/67°F
ELEVATION: approx. 822m/2696ft

Pogonomyrmex pima

4 nests/nest openings in fairly close proximity (all fit within a circle approx. 1.75m/5.7ft in diameter). 3 of the entrances surrounded by extremely fine, dark sand. The other was cryptic.

Many solitary foragers – one was seen carrying a live termite. Also some nest maintenance was being performed.

These ants were differentiated from the very similar Pogonomyrmex imberbiculus by the lack of the prominent, forwardly directed projection in front of each antennal fossa that is present in imberbiculus. Also, the dorsal surface of the petiolar node not strongly rugo-reticulate, as in P. imberbiculus.

DLQ LOC: A20171

Sahuarita, Arizona, USA

Sunny
TEMP: 22°C/71°F
ELEVATION: approx. 898m/2945ft

Acromyrmex versicolor

One of several large, multi-cratered colonies along side of road. Tall, sharp edged volcano-like nest mounds. Lots of activity – both nest maintenance and foraging. Workers retrieving plant material, including mesquite leaflets, from the ground.

Note: also many Veromessor pergandei colonies in area.

DLQ LOC: A20165

Sahuarita, Arizona, USA

Sunny
TEMP: 22°C/72°F
ELEVATION: approx. 961m/3152ft

Acromyrmex versicolor

Medium (approx. 1 foot diameter) nest in soft disturbed sandy soil at edge of road. Actual nest structure was not visible due to large amount of green leaf material present. Only the nest opening was clear of leaves. Nest opening consisted of a vertical, cave-like hole. A large number of foragers were retrieving thin green leaves from beneath a shrub (Dodonaea viscosa) in a nearby wash about 10-12 feet away and depositing the material on, and around the nest. Only a very few workers were actually seen to enter the nest with a leaf - almost all were left outside.

DLQ LOC: A20167

Sahuarita, Arizona, USA

Sunny
TEMP: 21°C/70°F
ELEVATION: approx. 898m/2945ft

Acromyrmex versicolor

Approx 20 workers on surface of small, low nest. A sparse foraging trail extended to the north. Workers were moving quite slowly.

DLQ LOC: A20163

Saguaro National Park (West) – Bajada Loop Drive

Sunny
TEMP: 15.5°C/60°F
ELEVATION: approx. 817m/2680ft

Acromyrmex versicolor

Very small (7 in) mound/crater in sandy soil on dirt road (close to edge of road).

About a dozen smaller workers on nest surface. They were moving very slowly due to the relatively low air temp. Small amount of leaf fragments on nest.

DLQ LOC: A20162-B

Saguaro National Park (West) – Bajada Loop Drive

Sunny
TEMP: 15.5°C/60°F
ELEVATION: approx. 817m/2680ft

Novomessor cockerelli

Large gravel nest with large central opening, in somewhat rocky soil. Several workers milling about and conducting light nest maintenance.

Distinguished from Novomessor albisetosus by the following: in N. cockerelli; longitudinal cephalic rugae do not extend all the way to the posterior border of head, also head extremely elongate, and the nest structure was typical of N. cockerelli.

DLQ LOC: A20162

Organ Pipe Cactus National Monument, AZ, USA

Sunny
TEMP: 18°C/64°F
ELEVATION: approx. 175m/1500ft

Atta Mexicana

Many hundreds of Atta mexicana workers foraging at edge of an arroyo/wash. Material was being transported to at least 3 lateral tunnel openings (the tunnels can extend more than 100 meters from the central nest location).

Several large majors/soldiers were active at the tunnel openings.

Note the presence of 2 pairs of spines on the promesonotum of Atta, as opposed to 3 pairs of spines on the promesonotum of Acromyrmex.

By the time we found these ants we were extremely tired and hungry, and pressed for time. In the rush to get some usable images, we neglected to positively ID the split and partially dead tree that was the main target of their foraging activities. I think it was whitethorn acacia (Vachellia constricta).

We were extremely careful not to disturb/harm the ants or any other park resources.

For more info on Atta mexicana see the work of Dr. Alex C. Mintzer.

DLQ LOC: A20161

Painted Rocks Petroglyph Site, Theba AZ
Stony soil, creosote/bursage scrub

Thin overcast/hazy sun
TEMP: 19°C/66°F
ELEVATION: 175m/576ft

Pogonomyrmex rugosus

No real nest superstructure – just a small amount of gravel, and single entrance hole.
Many workers active - loitering around nest entrance, removing debris from nest interior, and foraging.

P. rugosus and Veromessor pergandei were the dominant ants at this location. We also saw Myrmecosystus sp, and what I am sure was Pheidole gilvescens, but I was unable to get a photo of a major worker.

DLQ LOC: A19158

Painted Rocks Petroglyph Site, Theba AZ
Stony soil, creosote/bursage scrub

Thin overcast/hazy sun
TEMP: 17°C/62°F
ELEVATION: 175m/576ft

Veromessor pergandei

Triple crater. Many workers active – mostly doing nest maintenance, and some scavenging.

Pogonomyrmex rugosus and Veromessor pergandei were the dominant ants at this location. We also saw Myrmecosystus sp, and what I am sure was Pheidole gilvescens, but I was unable to get a photo of a major worker.

DLQ LOC: A19157

Casa Grande, AZ

Mostly Sunny
TEMP: 20°C/68°F
ELEVATION: 440m/1444ft

Pogonomyrmex rugosus

Large, low, flat gravel nest mound with single entrance and an auxiliary entrance about 0.8m away.
Lots of activity including foraging on trunk trails. Some workers were seen carrying tiny unidentified seeds back to the nest.

DLQ LOC: A19152

Casa Grande, AZ

Mostly Sunny
TEMP: 20.5°C/69°F
ELEVATION: 440m/1444ft

Pheidole xerophila (aka Pheidole xerophila tucsonica)

When first approaching this nest, we saw many agitated majors moving frantically around one of the entrances. Seconds later, a Ph. xerophila worker was seen emerging from the entrance – clutching a invading Solenopsis worker in its mandibles. The two ants struggled for a few minutes until I lost track of them while adjusting the camera.

Another Pheidole major was observed to carry a Solenopsis worker away from the nest and drop it apparently unharmed. One dead Pheidole major was seen about 30cm/12in from the entrance.

DLQ LOC: A19154

Casa Grande, AZ

Mostly Sunny
TEMP: 19°C/66°F
ELEVATION: 440m/1444ft

Pogonomyrmex desertorum

We returned to this location to re-visit a Pogonomyrmex pima colony that we observed on March 10, 2019. There was no sign of the P. pima nest – apparently having been obliterated by vehicle tracks, and no P. pima workers were seen.

However, about 12m/40ft south of where the pima nest was, we were surprised to find a Pogonomyrmex desertorum colony! This is my first location for this ant in Arizona (having observed them previously in Texas).

Approx 20 workers were loitering in the area around nest entrance. Several workers were seen ranging farther from the nest – they appeared to be foraging.

The nest consisted of a flat, barely visible sandy/gravel disc approx. 12.7cm/5in in diameter with single entrance.

Pogonomyrmex desertorum is a member of the ‘barbatus complex’, and in many ways the workers look like much smaller versions of Pogonomyrmex barbatus. Unlike P. barbatus though, P. desertorum workers are extremely docile.

This location is near the western limit of this ant’s range, and these workers differed in a couple of ways from the individuals we have observed in Texas. Most notably, in the more eastern portion (e.g. Texas) of P. desertorm’s range, in the words of A.C. Cole; “the posterior corners of the head are strongly shining and free of sculpture.” In this more western portion of P. desertorum’s range, again, in Cole’s words; “the cephalic rugae have encroached for such a considerable distance into the posterior corners of the head that some workers of a nest series may have these parts almost completely covered with very fine rugae which are sufficiently dense to obscure almost entirely the shining surface.”

DLQ LOC: A19151

Casa Grande, AZ

Mostly Sunny
TEMP: 18°C/64°F
ELEVATION: 440m/1444ft

Pheidole xerophila (also known as Pheidole xerophila tucsonica)

Typical Ph. xerophila colony with three tiny mounds/entrances, in fine, sandy soil.

Many major workers active. These ants were moving slowly because of the relatively low air temperature – allowing me to get good diagnostic photos.

DLQ LOC: A19150

Tonto N.F. - Four Peaks Wilderness Area

Pheidole xerophila

This nest had 3 small mounds, each with a single entrance hole. Much activity, with numerous minor workers foraging along trunk trails. Only 1 major worker seen. This individual was missing 2 legs and part of its left antenna.
There are many other Ph. xerophila colonies in this area.
NOTE: This variant is also known as Pheidole xerophila tucsonica.

Sunny
TEMP: 25.5°C/78°F
ELEVATION: 790m/2592ft

DLQ LOC: A19149