● Berg Ln / Cooley Rd, Bend [Deschutes Co], OR USA [el. 1060 m / 3478 ft] view location in Google Maps »
 ● 7/19/09 7:16PM sunny, air temp: 28°C / 83°F

[IMAGE 2 of 2] This very rough-looking (this image has not been over-sharpened) Pogonomyrmex salinus worker was imaged while gnawing on the femur of a large grasshopper leg, in central Oregon. As can be seen here, a good portion of the lower marginal area has been broken away by the ant's mandibles. The heavier medial area of the leg (with raised chevron-like ridges, and surrounded by the thick 'carinula') was apparently too tough for this determined ant, and she seemed unable to make any more progress. We believe the Pogo was trying to separate this large object into easily transportable pieces (the tibia was still attached, so the grasshopper leg was more than twice the length as can be seen in these images). [scroll down for additional notes/references]

ADDITIONAL NOTES/REFERENCES:

Because they are referred to as harvester ants, Pogos are often thought of as strict granivores (feeding only on grains and seeds). Though they do collect great quantities of  plant-based nutritional resources, they are also known (to a lesser degree) to scavenge arthropod carrion (dead insects, spiders, etc) in sometimes significant amounts. 

The degree to which Pogonomyrmex ants utilize this type of food, varies from species to species, and on many other factors, including variation coinciding with seasonal changes, or local events like rainfall.

In some species, such as P. montanus, insects and insect parts may make up more than 25% of the total food intake for the colony. One study of Pogonomyrmex salinus in southeastern Idaho, found that only 2% of returning foragers carried insects or dung (the authors add; "Although insects were included in only 2% of the foraging trips, they accounted for 12% of the food weight per unit trip".

While most of this arthropod/insect food is apparently scavenged from already-dead creatures, Pogonomyrmex ants (and other ant species) are famous for sometimes preying on live termites - especially during the termite's mating swarms. Also, Pogonomyrmex rugosus has been observed to prey on live  grass cicadas (Beameria vanosa) as they emerge from the ground in Spring.

Clark & Blom observed  Pogonomyrmex salinus workers feeding on the carcass of a sagebrush lizard (Sceloporus graciosus), in Idaho - it is is not known if the ants killed the lizard as well. Other Pogos have also been been known to feed on already-dead reptiles and small mammals (small bits of flesh are removed by the ants, and carried back to the nest). Dead mammals and reptiles are not known to serve as a major source of food for Pogos.


·Clark, W.H. & P.E. Blum. 1991. Observations of Ants (Hymenoptera: Formicidae: Myrmicinae, Formicinae, Dolichorderinae) Utilizing Carrion. The Southwestern Naturalist Vol.36, No.1, March 1991
·Jorgensen C.D. & Porter, S.D. 1982. Foraging Behavior of Pogonomyrmex owyheei in Southeast Idaho. Environmental Entomology, Vol. 11, No. 2, April 1982
·MacKay, W.P. 1981. A Comparison of Nest Phenologies of Three Species of Pogonomyrmex Harvester Ants (Hymenoptera: Formicidae). Psyche, Vol. 88, No. 1-2, 1981
·Whitford, W.G & E. Jackson. 2007. Seed Harvester Ants (Pogonomyrmex rugosus) as "Pulse" Predators. Journal of Arid Environments 70 (2007) 549-552
 ● Berg Ln / Cooley Rd, Bend [Deschutes Co], OR USA [el. 1060 m / 3478 ft] view location in Google Maps »
 ● 7/19/09 7:16PM sunny, air temp: 28°C / 83°F

[IMAGE 1 of 2] This very rough-looking Pogonomyrmex salinus worker was imaged while gnawing on the femur of a large grasshopper leg, in central Oregon. As can be seen here, a good portion of the lower marginal area has been broken away by the ant's mandibles. The heavier medial area of the leg (with raised chevron-like ridges, and surrounded by the thick 'carinula') was apparently too tough for this determined ant, and she seemed unable to make any more progress. We believe the Pogo was trying to separate this large object into easily transportable pieces (the tibia was still attached, so the grasshopper leg was more than twice the length as can be seen in these images). [scroll down for additional notes/references]
ADDITIONAL NOTES/REFERENCES:

Because they are referred to as harvester ants, Pogos are often thought of as strict granivores (feeding only on grains and seeds). Though they do collect great quantities of  plant-based nutritional resources, they are also known (to a lesser degree) to scavenge arthropod carrion (dead insects, spiders, etc) in sometimes significant amounts. 

The degree to which Pogonomyrmex ants utilize this type of food, varies from species to species, and on many other factors, including variation coinciding with seasonal changes, or local events like rainfall.

In some species, such as P. montanus, insects and insect parts may make up more than 25% of the total food intake for the colony. One study of Pogonomyrmex salinus in southeastern Idaho, found that only 2% of returning foragers carried insects or dung (the authors add; "Although insects were included in only 2% of the foraging trips, they accounted for 12% of the food weight per unit trip".

While most of this arthropod/insect food is apparently scavenged from already-dead creatures, Pogonomyrmex ants (and other ant species) are famous for sometimes preying on live termites - especially during the termite's mating swarms. Also, Pogonomyrmex rugosus has been observed to prey on live  grass cicadas (Beameria vanosa) as they emerge from the ground in Spring.

Clark & Blom observed  Pogonomyrmex salinus workers feeding on the carcass of a sagebrush lizard (Sceloporus graciosus), in Idaho - it is is not known if the ants killed the lizard as well. Other Pogos have also been been known to feed on already-dead reptiles and small mammals (small bits of flesh are removed by the ants, and carried back to the nest). Dead mammals and reptiles are not known to serve as a major source of food for Pogos.


·Clark, W.H. & P.E. Blum. 1991. Observations of Ants (Hymenoptera: Formicidae: Myrmicinae, Formicinae, Dolichorderinae) Utilizing Carrion. The Southwestern Naturalist Vol.36, No.1, March 1991
·Jorgensen C.D. & Porter, S.D. 1982. Foraging Behavior of Pogonomyrmex owyheei in Southeast Idaho. Environmental Entomology, Vol. 11, No. 2, April 1982
·MacKay, W.P. 1981. A Comparison of Nest Phenologies of Three Species of Pogonomyrmex Harvester Ants (Hymenoptera: Formicidae). Psyche, Vol. 88, No. 1-2, 1981
·Whitford, W.G & E. Jackson. 2007. Seed Harvester Ants (Pogonomyrmex rugosus) as "Pulse" Predators. Journal of Arid Environments 70 (2007) 549-552
 ● NW of Mattawa [Grant Co], WA USA [el. 152 m / 500 ft]  view location in Google Maps »
 ● 9/27/09 8:26AM sunny, air temp: 17°C / 62°F

[IMAGE 1 of 3] Pheidole creightoni major and minor workers, attempting to transport a Pogonomyrmex salinus carcass (with attached debris). Presumably, the Pogo remains were being taken back to the Pheidole nest, about .6m / 2ft away. It is likely that the Pogo had been killed earlier by a spider (silk/web was present, and can be seen in these images). [scroll down for additional notes/references]
ADDITIONAL NOTES/REFERENCES:

We have found Pheidole creightoni living in close proximity to P. salinus at a location in central Washington state. In one instance, the distance between the entrances of a large  P. salinus nest, and a Pheidole creightoni nest, was measured at 1.4m / 59 in., and at least two P. creightoni nests appeared to be built on the abandoned remnants of P. salinus mounds. The  Pheidole nests are (at least in some cases) in the form of a small gravel crater, often with much chaff and Pogo carcasses present.

On one occasion (9/27/09) we observed  Pheidole creightoni major and minor workers foraging on the gravel portions of a large, low, active Pogonomyrmex salinus nest mound. The Pogo workers appeared to take no notice of the tiny trespassers. A few of the Pheidole workers picked up small pieces of plant matter, and headed back toward their nest. A 'foraging party' (consisting of one major, and six minors) was also seen emerging from the Pheidole nest, in 'single file' (though not traveling toward the P. salinus mound, but in a different direction). 

W.S. Creighton observed this ant (P. creightoni) near Applegate, Oregon, nesting in close association with the ant Messor andrei (an ant somewhat similar to P. salinus in appearance and habits). He noted that the Pheidole nests were ringed with chaff (discarded seed/plant debris) indicating that seeds were probably an important part of their diet (he also fed then freshly-killed squirrel meat, which they accepted). As mentioned above, we also see large amounts of chaff around/on P. creightoni nests, with the addition of Pogonomyrmex salinus body parts and carcasses (and rarely other ant/insect parts), indicating a possible reliance on scavenged insects, in addition to seeds, as a food source. Since some of the Pheidole creightoni nests that we have observed seem to be built on/very near the sites of abandoned Pogo colonies, we think it is possible that some of these carcasses are brought up from below by excavating P. creightoni workers. We will observe these ants more thoroughly in our 2010 season.

The Pheidole creightoni workers pictured here were differentiated from the very similar species, Pheidole californica, by the following characters: postpetiole of major 'spinose' in dorsal view; lateral cephalic setea of major, short and erect/nearly erect, in face-on view; propodeal spines of major in the form of 'long blunt pegs'; postpetiole of minor 'trapezoidal' in dorsal view.       

·Burge, D.O. 2005. Taxonomy, Biology, and Distribution of Seed Harvesting Ants in the Pheidole californica Complex (Hymenoptera: Formicidae)
·Gregg, R.E. 1955. A New Species of Ant Belonging to the Pheidole Pilifera Complex (Hymenoptera: Formicidae). Psyche, Vol. 62, No.1, March, 1955
·Wilson, E.O. 2003. Pheidole in the New World: A Dominant Hyperdiverse Ant Genus. Harvard University Press, Cambridge, Massachusetts
 ● NW of Mattawa [Grant Co], WA USA [el. 152 m / 500 ft]  view location in Google Maps »
 ● 9/27/09 8:24AM sunny, air temp: 17°C / 62°F

[IMAGE 2 of 3] A Pheidole creightoni major worker, attempting to transport a Pogonomyrmex salinus carcass (with attached debris). Presumably, the Pogo remains were being taken back to the Pheidole nest, about .6m / 2ft away. It is likely that the Pogo had been killed earlier by a spider (silk/web was present, and can be seen in these images). [scroll down for additional notes/references]
ADDITIONAL NOTES/REFERENCES:

We have found Pheidole creightoni living in close proximity to P. salinus at a location in central Washington state. In one instance, the distance between the entrances of a large  P. salinus nest, and a Pheidole creightoni nest, was measured at 1.4m / 59 in., and at least two P. creightoni nests appeared to be built on the abandoned remnants of P. salinus mounds. The  Pheidole nests are (at least in some cases) in the form of a small gravel crater, often with much chaff and Pogo carcasses present.

On one occasion (9/27/09) we observed  Pheidole creightoni major and minor workers foraging on the gravel portions of a large, low, active Pogonomyrmex salinus nest mound. The Pogo workers appeared to take no notice of the tiny trespassers. A few of the Pheidole workers picked up small pieces of plant matter, and headed back toward their nest. A 'foraging party' (consisting of one major, and six minors) was also seen emerging from the Pheidole nest, in 'single file' (though not traveling toward the P. salinus mound, but in a different direction). 

W.S. Creighton observed this ant (P. creightoni) near Applegate, Oregon, nesting in close association with the ant Messor andrei (an ant somewhat similar to P. salinus in appearance and habits). He noted that the Pheidole nests were ringed with chaff (discarded seed/plant debris) indicating that seeds were probably an important part of their diet (he also fed then freshly-killed squirrel meat, which they accepted). As mentioned above, we also see large amounts of chaff around/on P. creightoni nests, with the addition of Pogonomyrmex salinus body parts and carcasses (and rarely other ant/insect parts), indicating a possible reliance on scavenged insects, in addition to seeds, as a food source. Since some of the Pheidole creightoni nests that we have observed seem to be built on/very near the sites of abandoned Pogo colonies, we think it is possible that some of these carcasses are brought up from below by excavating P. creightoni workers. We will observe these ants more thoroughly in our 2010 season.

The Pheidole creightoni workers pictured here were differentiated from the very similar species, Pheidole californica, by the following characters: postpetiole of major 'spinose' in dorsal view; lateral cephalic setea of major, short and erect/nearly erect, in face-on view; propodeal spines of major in the form of 'long blunt pegs'; postpetiole of minor 'trapezoidal' in dorsal view.       

·Burge, D.O. 2005. Taxonomy, Biology, and Distribution of Seed Harvesting Ants in the Pheidole californica Complex (Hymenoptera: Formicidae)
·Gregg, R.E. 1955. A New Species of Ant Belonging to the Pheidole Pilifera Complex (Hymenoptera: Formicidae). Psyche, Vol. 62, No.1, March, 1955
·Wilson, E.O. 2003. Pheidole in the New World: A Dominant Hyperdiverse Ant Genus. Harvard University Press, Cambridge, Massachusetts
 ● NW of Mattawa [Grant Co], WA USA [el. 152 m / 500 ft]  view location in Google Maps »
 ● 9/27/09 8:24AM sunny, air temp: 17°C / 62°F

[IMAGE 1 of 3] A Pheidole creightoni major worker, attempting to transport a Pogonomyrmex salinus carcass (with attached debris). Presumably, the Pogo remains were being taken back to the Pheidole nest, about .6m / 2ft away. It is likely that the Pogo had been killed earlier by a spider (silk/web was present, and can be seen in these images). [scroll down for additional notes/references]
ADDITIONAL NOTES/REFERENCES:

We have found Pheidole creightoni living in close proximity to P. salinus at a location in central Washington state. In one instance, the distance between the entrances of a large  P. salinus nest, and a Pheidole creightoni nest, was measured at 1.4m / 59 in., and at least two P. creightoni nests appeared to be built on the abandoned remnants of P. salinus mounds. The  Pheidole nests are (at least in some cases) in the form of a small gravel crater, often with much chaff and Pogo carcasses present.

On one occasion (9/27/09) we observed  Pheidole creightoni major and minor workers foraging on the gravel portions of a large, low, active Pogonomyrmex salinus nest mound. The Pogo workers appeared to take no notice of the tiny trespassers. A few of the Pheidole workers picked up small pieces of plant matter, and headed back toward their nest. A 'foraging party' (consisting of one major, and six minors) was also seen emerging from the Pheidole nest, in 'single file' (though not traveling toward the P. salinus mound, but in a different direction). 

W.S. Creighton observed this ant (P. creightoni) near Applegate, Oregon, nesting in close association with the ant Messor andrei (an ant somewhat similar to P. salinus in appearance and habits). He noted that the Pheidole nests were ringed with chaff (discarded seed/plant debris) indicating that seeds were probably an important part of their diet (he also fed then freshly-killed squirrel meat, which they accepted). As mentioned above, we also see large amounts of chaff around/on P. creightoni nests, with the addition of Pogonomyrmex salinus body parts and carcasses (and rarely other ant/insect parts), indicating a possible reliance on scavenged insects, in addition to seeds, as a food source. Since some of the Pheidole creightoni nests that we have observed seem to be built on/very near the sites of abandoned Pogo colonies, we think it is possible that some of these carcasses are brought up from below by excavating P. creightoni workers. We will observe these ants more thoroughly in our 2010 season.

The Pheidole creightoni workers pictured here were differentiated from the very similar species, Pheidole californica, by the following characters: postpetiole of major 'spinose' in dorsal view; lateral cephalic setea of major, short and erect/nearly erect, in face-on view; propodeal spines of major in the form of 'long blunt pegs'; postpetiole of minor 'trapezoidal' in dorsal view.       

·Burge, D.O. 2005. Taxonomy, Biology, and Distribution of Seed Harvesting Ants in the Pheidole californica Complex (Hymenoptera: Formicidae)
·Gregg, R.E. 1955. A New Species of Ant Belonging to the Pheidole Pilifera Complex (Hymenoptera: Formicidae). Psyche, Vol. 62, No.1, March, 1955
·Wilson, E.O. 2003. Pheidole in the New World: A Dominant Hyperdiverse Ant Genus. Harvard University Press, Cambridge, Massachusetts
 ● Boardman [Morrow Co], OR USA [El. 91m/298 ft] view location in Google Maps »
 ● 7/22/09 9:15AM sunny, air temp: 27°C / 80°F

[IMAGE 2 OF 2] Making remarkably good progress, a Pogonomyrmex salinus worker (with intermittent help from a nestmate) transports the legless carcass of an earwig (Dermaptera: Forficulidae). The ants were moving their cargo away from the nest entrance. It is not known if the earwig had been previously scavenged by the Pogos (as a  potential food source), or if it just wandered into the nest, and was killed by the ants...
 ● Boardman [Morrow Co], OR USA [El. 91m/298 ft] view location in Google Maps »
 ● 7/22/09 9:13AM sunny, air temp: 27°C / 80°F

[IMAGE 1 OF 2] Making remarkably good progress, a Pogonomyrmex salinus worker (with intermittent help from a nestmate) transports the legless carcass of an earwig (Dermaptera: Forficulidae). The ants were moving their cargo away from the nest entrance. It is not known if the earwig had been previously scavenged by the Pogos (as a  potential food source), or if it just wandered into the nest, and was killed by the ants...
 ● NW of Mattawa [Grant Co], WA USA [el. 152 m / 500 ft]  view location in Google Maps »
 ● 9/27/09 9:58AM sunny, air temp: 18°C / 65°F

[IMAGE 2 of 2] In a rare display of cooperative scavenging, a group of four Pogonomyrmex salinus workers move an incomplete moth carcass toward their nest, in central Washington state. They did eventually reach the entrance, and with some difficulty, pulled the moth inside. [scroll down for additional notes/references]

ADDITIONAL NOTES/REFERENCES:

Because they are referred to as harvester ants, Pogos are often thought of as strict granivores (feeding only on grains and seeds). Though they do collect great quantities of  plant-based nutritional resources, they are also known (to a lesser degree) to scavenge arthropod carrion (dead insects, spiders, etc) in sometimes significant amounts. 

The degree to which Pogonomyrmex ants utilize this type of food, varies from species to species, and on many other factors, including variation coinciding with seasonal changes, or local events like rainfall.

In some species, such as P. montanus, insects and insect parts may make up more than 25% of the total food intake for the colony. One study of Pogonomyrmex salinus in southeastern Idaho, found that only 2% of returning foragers carried insects or dung (the authors add; "Although insects were included in only 2% of the foraging trips, they accounted for 12% of the food weight per unit trip".

While most of this arthropod/insect food is apparently scavenged from already-dead creatures, Pogonomyrmex ants (and other ant species) are famous for sometimes preying on live termites - especially during the termite's mating swarms. Also, Pogonomyrmex rugosus has been observed to prey on live  grass cicadas (Beameria vanosa) as they emerge from the ground in Spring.

Clark & Blom observed  Pogonomyrmex salinus workers feeding on the carcass of a sagebrush lizard (Sceloporus graciosus), in Idaho - it is is not known if the ants killed the lizard as well. Other Pogos have also been been known to feed on already-dead reptiles and small mammals (small bits of flesh are removed by the ants, and carried back to the nest). Dead mammals and reptiles are not known to serve as a major source of food for Pogos.


·Clark, W.H. & P.E. Blum. 1991. Observations of Ants (Hymenoptera: Formicidae: Myrmicinae, Formicinae, Dolichorderinae) Utilizing Carrion. The Southwestern Naturalist Vol.36, No.1, March 1991
·Jorgensen C.D. & Porter, S.D. 1982. Foraging Behavior of Pogonomyrmex owyheei in Southeast Idaho. Environmental Entomology, Vol. 11, No. 2, April 1982
·MacKay, W.P. 1981. A Comparison of Nest Phenologies of Three Species of Pogonomyrmex Harvester Ants (Hymenoptera: Formicidae). Psyche, Vol. 88, No. 1-2, 1981
·Whitford, W.G & E. Jackson. 2007. Seed Harvester Ants (Pogonomyrmex rugosus) as "Pulse" Predators. Journal of Arid Environments 70 (2007) 549-552
 ● NW of Mattawa [Grant Co], WA USA [el. 152 m / 500 ft]  view location in Google Maps »
 ● 9/27/09 9:53AM sunny, air temp: 18°C / 65°F

[IMAGE 1 of 2] In a rare display of cooperative scavenging, a group of four Pogonomyrmex salinus workers move an incomplete moth carcass toward their nest, in central Washington state. They did eventually reach the entrance, and with some difficulty, pulled the moth inside. [scroll down for additional notes/references]

ADDITIONAL NOTES/REFERENCES:

Because they are referred to as harvester ants, Pogos are often thought of as strict granivores (feeding only on grains and seeds). Though they do collect great quantities of  plant-based nutritional resources, they are also known (to a lesser degree) to scavenge arthropod carrion (dead insects, spiders, etc) in sometimes significant amounts. 

The degree to which Pogonomyrmex ants utilize this type of food, varies from species to species, and on many other factors, including variation coinciding with seasonal changes, or local events like rainfall.

In some species, such as P. montanus, insects and insect parts may make up more than 25% of the total food intake for the colony. One study of Pogonomyrmex salinus in southeastern Idaho, found that only 2% of returning foragers carried insects or dung (the authors add; "Although insects were included in only 2% of the foraging trips, they accounted for 12% of the food weight per unit trip".

While most of this arthropod/insect food is apparently scavenged from already-dead creatures, Pogonomyrmex ants (and other ant species) are famous for sometimes preying on live termites - especially during the termite's mating swarms. Also, Pogonomyrmex rugosus has been observed to prey on live  grass cicadas (Beameria vanosa) as they emerge from the ground in Spring.

Clark & Blom observed  Pogonomyrmex salinus workers feeding on the carcass of a sagebrush lizard (Sceloporus graciosus), in Idaho - it is is not known if the ants killed the lizard as well. Other Pogos have also been been known to feed on already-dead reptiles and small mammals (small bits of flesh are removed by the ants, and carried back to the nest). Dead mammals and reptiles are not known to serve as a major source of food for Pogos.


·Clark, W.H. & P.E. Blum. 1991. Observations of Ants (Hymenoptera: Formicidae: Myrmicinae, Formicinae, Dolichorderinae) Utilizing Carrion. The Southwestern Naturalist Vol.36, No.1, March 1991
·Jorgensen C.D. & Porter, S.D. 1982. Foraging Behavior of Pogonomyrmex owyheei in Southeast Idaho. Environmental Entomology, Vol. 11, No. 2, April 1982
·MacKay, W.P. 1981. A Comparison of Nest Phenologies of Three Species of Pogonomyrmex Harvester Ants (Hymenoptera: Formicidae). Psyche, Vol. 88, No. 1-2, 1981
·Whitford, W.G & E. Jackson. 2007. Seed Harvester Ants (Pogonomyrmex rugosus) as "Pulse" Predators. Journal of Arid Environments 70 (2007) 549-552
● NW of Mattawa [Grant Co], WA USA [el. 152 m / 500 ft] view location in Google Maps »
● 9/27/09 8:24AM sunny, air temp: 17°C / 62°F

[IMAGE 2 of 3] A Pheidole creightoni major worker, attempting to transport a Pogonomyrmex salinus carcass (with attached debris). Presumably, the Pogo remains were being taken back to the Pheidole nest, about .6m / 2ft away. It is likely that the Pogo had been killed earlier by a spider (silk/web was present, and can be seen in these images). [scroll down for additional notes/references]

ADDITIONAL NOTES/REFERENCES:

We have found Pheidole creightoni living in close proximity to P. salinus at a location in central Washington state. In one instance, the distance between the entrances of a large P. salinus nest, and a Pheidole creightoni nest, was measured at 1.4m / 59 in., and at least two P. creightoni nests appeared to be built on the abandoned remnants of P. salinus mounds. The Pheidole nests are (at least in some cases) in the form of a small gravel crater, often with much chaff and Pogo carcasses present.

On one occasion (9/27/09) we observed Pheidole creightoni major and minor workers foraging on the gravel portions of a large, low, active Pogonomyrmex salinus nest mound. The Pogo workers appeared to take no notice of the tiny trespassers. A few of the Pheidole workers picked up small pieces of plant matter, and headed back toward their nest. A 'foraging party' (consisting of one major, and six minors) was also seen emerging from the Pheidole nest, in 'single file' (though not traveling toward the P. salinus mound, but in a different direction).

W.S. Creighton observed this ant (P. creightoni) near Applegate, Oregon, nesting in close association with the ant Messor andrei (an ant somewhat similar to P. salinus in appearance and habits). He noted that the Pheidole nests were ringed with chaff (discarded seed/plant debris) indicating that seeds were probably an important part of their diet (he also fed then freshly-killed squirrel meat, which they accepted). As mentioned above, we also see large amounts of chaff around/on P. creightoni nests, with the addition of Pogonomyrmex salinus body parts and carcasses (and rarely other ant/insect parts), indicating a possible reliance on scavenged insects, in addition to seeds, as a food source. Since some of the Pheidole creightoni nests that we have observed seem to be built on/very near the sites of abandoned Pogo colonies, we think it is possible that some of these carcasses are brought up from below by excavating P. creightoni workers. We will observe these ants more thoroughly in our 2010 season.

The Pheidole creightoni workers pictured here were differentiated from the very similar species, Pheidole californica, by the following characters: postpetiole of major 'spinose' in dorsal view; lateral cephalic setea of major, short and erect/nearly erect, in face-on view; propodeal spines of major in the form of 'long blunt pegs'; postpetiole of minor 'trapezoidal' in dorsal view.

·Burge, D.O. 2005. Taxonomy, Biology, and Distribution of Seed Harvesting Ants in the Pheidole californica Complex (Hymenoptera: Formicidae)
·Gregg, R.E. 1955. A New Species of Ant Belonging to the Pheidole Pilifera Complex (Hymenoptera: Formicidae). Psyche, Vol. 62, No.1, March, 1955
·Wilson, E.O. 2003. Pheidole in the New World: A Dominant Hyperdiverse Ant Genus. Harvard University Press, Cambridge, Massachusetts

● NW of Mattawa [Grant Co], WA USA [el. 152 m / 500 ft] view location in Google Maps » ● 9/27/09 8:24AM sunny, air temp: 17°C / 62°F
[IMAGE 2 of 3] A Pheidole creightoni major worker, attempting to transport a Pogonomyrmex salinus carcass (with attached debris). Presumably, the Pogo remains were being taken back to the Pheidole nest, about .6m / 2ft away. It is likely that the Pogo had been killed earlier by a spider (silk/web was present, and can be seen in these images). [scroll down for additional notes/references]
ADDITIONAL NOTES/REFERENCES: We have found Pheidole creightoni living in close proximity to P. salinus at a location in central Washington state. In one instance, the distance between the entrances of a large P. salinus nest, and a Pheidole creightoni nest, was measured at 1.4m / 59 in., and at least two P. creightoni nests appeared to be built on the abandoned remnants of P. salinus mounds. The Pheidole nests are (at least in some cases) in the form of a small gravel crater, often with much chaff and Pogo carcasses present. On one occasion (9/27/09) we observed Pheidole creightoni major and minor workers foraging on the gravel portions of a large, low, active Pogonomyrmex salinus nest mound. The Pogo workers appeared to take no notice of the tiny trespassers. A few of the Pheidole workers picked up small pieces of plant matter, and headed back toward their nest. A 'foraging party' (consisting of one major, and six minors) was also seen emerging from the Pheidole nest, in 'single file' (though not traveling toward the P. salinus mound, but in a different direction). W.S. Creighton observed this ant (P. creightoni) near Applegate, Oregon, nesting in close association with the ant Messor andrei (an ant somewhat similar to P. salinus in appearance and habits). He noted that the Pheidole nests were ringed with chaff (discarded seed/plant debris) indicating that seeds were probably an important part of their diet (he also fed then freshly-killed squirrel meat, which they accepted). As mentioned above, we also see large amounts of chaff around/on P. creightoni nests, with the addition of Pogonomyrmex salinus body parts and carcasses (and rarely other ant/insect parts), indicating a possible reliance on scavenged insects, in addition to seeds, as a food source. Since some of the Pheidole creightoni nests that we have observed seem to be built on/very near the sites of abandoned Pogo colonies, we think it is possible that some of these carcasses are brought up from below by excavating P. creightoni workers. We will observe these ants more thoroughly in our 2010 season. The Pheidole creightoni workers pictured here were differentiated from the very similar species, Pheidole californica, by the following characters: postpetiole of major 'spinose' in dorsal view; lateral cephalic setea of major, short and erect/nearly erect, in face-on view; propodeal spines of major in the form of 'long blunt pegs'; postpetiole of minor 'trapezoidal' in dorsal view. ·Burge, D.O. 2005. Taxonomy, Biology, and Distribution of Seed Harvesting Ants in the Pheidole californica Complex (Hymenoptera: Formicidae) ·Gregg, R.E. 1955. A New Species of Ant Belonging to the Pheidole Pilifera Complex (Hymenoptera: Formicidae). Psyche, Vol. 62, No.1, March, 1955 ·Wilson, E.O. 2003. Pheidole in the New World: A Dominant Hyperdiverse Ant Genus. Harvard University Press, Cambridge, Massachusetts
" href="javascript:openLB(1110329274,'',XLarge,'',1024,683);"> ● NW of Mattawa [Grant Co], WA USA [el. 152 m / 500 ft]  view location in Google Maps »
 ● 9/27/09 8:24AM sunny, air temp: 17°C / 62°F

[IMAGE 2 of 3] A Pheidole creightoni major worker, attempting to transport a Pogonomyrmex salinus carcass (with attached debris). Presumably, the Pogo remains were being taken back to the Pheidole nest, about .6m / 2ft away. It is likely that the Pogo had been killed earlier by a spider (silk/web was present, and can be seen in these images). [scroll down for additional notes/references]
ADDITIONAL NOTES/REFERENCES:

We have found Pheidole creightoni living in close proximity to P. salinus at a location in central Washington state. In one instance, the distance between the entrances of a large  P. salinus nest, and a Pheidole creightoni nest, was measured at 1.4m / 59 in., and at least two P. creightoni nests appeared to be built on the abandoned remnants of P. salinus mounds. The  Pheidole nests are (at least in some cases) in the form of a small gravel crater, often with much chaff and Pogo carcasses present.

On one occasion (9/27/09) we observed  Pheidole creightoni major and minor workers foraging on the gravel portions of a large, low, active Pogonomyrmex salinus nest mound. The Pogo workers appeared to take no notice of the tiny trespassers. A few of the Pheidole workers picked up small pieces of plant matter, and headed back toward their nest. A 'foraging party' (consisting of one major, and six minors) was also seen emerging from the Pheidole nest, in 'single file' (though not traveling toward the P. salinus mound, but in a different direction). 

W.S. Creighton observed this ant (P. creightoni) near Applegate, Oregon, nesting in close association with the ant Messor andrei (an ant somewhat similar to P. salinus in appearance and habits). He noted that the Pheidole nests were ringed with chaff (discarded seed/plant debris) indicating that seeds were probably an important part of their diet (he also fed then freshly-killed squirrel meat, which they accepted). As mentioned above, we also see large amounts of chaff around/on P. creightoni nests, with the addition of Pogonomyrmex salinus body parts and carcasses (and rarely other ant/insect parts), indicating a possible reliance on scavenged insects, in addition to seeds, as a food source. Since some of the Pheidole creightoni nests that we have observed seem to be built on/very near the sites of abandoned Pogo colonies, we think it is possible that some of these carcasses are brought up from below by excavating P. creightoni workers. We will observe these ants more thoroughly in our 2010 season.

The Pheidole creightoni workers pictured here were differentiated from the very similar species, Pheidole californica, by the following characters: postpetiole of major 'spinose' in dorsal view; lateral cephalic setea of major, short and erect/nearly erect, in face-on view; propodeal spines of major in the form of 'long blunt pegs'; postpetiole of minor 'trapezoidal' in dorsal view.       

·Burge, D.O. 2005. Taxonomy, Biology, and Distribution of Seed Harvesting Ants in the Pheidole californica Complex (Hymenoptera: Formicidae)
·Gregg, R.E. 1955. A New Species of Ant Belonging to the Pheidole Pilifera Complex (Hymenoptera: Formicidae). Psyche, Vol. 62, No.1, March, 1955
·Wilson, E.O. 2003. Pheidole in the New World: A Dominant Hyperdiverse Ant Genus. Harvard University Press, Cambridge, Massachusetts
● NW of Mattawa [Grant Co], WA USA [el. 152 m / 500 ft] view location in Google Maps »
● 9/27/09 8:24AM sunny, air temp: 17°C / 62°F

[IMAGE 2 of 3] A Pheidole creightoni major worker, attempting to transport a Pogonomyrmex salinus carcass (with attached debris). Presumably, the Pogo remains were being taken back to the Pheidole nest, about .6m / 2ft away. It is likely that the Pogo had been killed earlier by a spider (silk/web was present, and can be seen in these images). [scroll down for additional notes/references]

ADDITIONAL NOTES/REFERENCES:

We have found Pheidole creightoni living in close proximity to P. salinus at a location in central Washington state. In one instance, the distance between the entrances of a large P. salinus nest, and a Pheidole creightoni nest, was measured at 1.4m / 59 in., and at least two P. creightoni nests appeared to be built on the abandoned remnants of P. salinus mounds. The Pheidole nests are (at least in some cases) in the form of a small gravel crater, often with much chaff and Pogo carcasses present.

On one occasion (9/27/09) we observed Pheidole creightoni major and minor workers foraging on the gravel portions of a large, low, active Pogonomyrmex salinus nest mound. The Pogo workers appeared to take no notice of the tiny trespassers. A few of the Pheidole workers picked up small pieces of plant matter, and headed back toward their nest. A 'foraging party' (consisting of one major, and six minors) was also seen emerging from the Pheidole nest, in 'single file' (though not traveling toward the P. salinus mound, but in a different direction).

W.S. Creighton observed this ant (P. creightoni) near Applegate, Oregon, nesting in close association with the ant Messor andrei (an ant somewhat similar to P. salinus in appearance and habits). He noted that the Pheidole nests were ringed with chaff (discarded seed/plant debris) indicating that seeds were probably an important part of their diet (he also fed then freshly-killed squirrel meat, which they accepted). As mentioned above, we also see large amounts of chaff around/on P. creightoni nests, with the addition of Pogonomyrmex salinus body parts and carcasses (and rarely other ant/insect parts), indicating a possible reliance on scavenged insects, in addition to seeds, as a food source. Since some of the Pheidole creightoni nests that we have observed seem to be built on/very near the sites of abandoned Pogo colonies, we think it is possible that some of these carcasses are brought up from below by excavating P. creightoni workers. We will observe these ants more thoroughly in our 2010 season.

The Pheidole creightoni workers pictured here were differentiated from the very similar species, Pheidole californica, by the following characters: postpetiole of major 'spinose' in dorsal view; lateral cephalic setea of major, short and erect/nearly erect, in face-on view; propodeal spines of major in the form of 'long blunt pegs'; postpetiole of minor 'trapezoidal' in dorsal view.

·Burge, D.O. 2005. Taxonomy, Biology, and Distribution of Seed Harvesting Ants in the Pheidole californica Complex (Hymenoptera: Formicidae)
·Gregg, R.E. 1955. A New Species of Ant Belonging to the Pheidole Pilifera Complex (Hymenoptera: Formicidae). Psyche, Vol. 62, No.1, March, 1955
·Wilson, E.O. 2003. Pheidole in the New World: A Dominant Hyperdiverse Ant Genus. Harvard University Press, Cambridge, Massachusetts

See photo in original gallery.
All Images, Video and Text (unless otherwise noted) © 2010/11/12 David Louis Quinn