Pogonomyrmex occidentalis (Western Harvester Ant) Care Sheet
This guide was compiled and written by Hugmaster of the 'Canadian Ant-Keepers' discord server, which can be found here. https://discord.gg/tDP8qQgRzq
This guide has been posted with the permission of the authors. The original article may be found here. I have also made some edits based on my own observations
Caresheet – Pogonomyrmex Occidentalis (Western Harvester Ant)
Pogonomyrmex Occidentalis is a species of ant that is almost never found outside of clearings and, despite its reputation as a ‘desert’ ant, never in completely arid habitat. But it can nest in many sites otherwise, often at higher elevation grasslands.
Author Note: These are some of the largest and most active ants a Canadian antkeeper can be graced in raising. In the wild, their dead workers are an important food source for many other ant species and lizards (Myrmecocystus mexicanus, to name only one). Careful, they are known to have a bad temper, which is good for observation! Their most common abbreviation is ‘Pogo’, as will be used in the rest of the document.
Before beginning, please make sure you have at least one bag of sunflower seeds or natural unflavored seeds ready to mash with your mortar and pestle (almond, peanuts, etc)
Origin: North America, along with a couple other subspecies (Salinus, Badius), they are rarer in canada.
Habitat: Humidity and heat are the most important things for them, Pogos are highly destructive and will make nests with whatever they can find to capture heat from the sun, most often soil and gravel. They are most often found in open plains and actively clear most vegetation from their mounds. They prefer malleable soils and will dig up to 2 meters in their search of moisture.
Colony form: Monogynous, the colony become very skittish: aggressive once they move past a certain number, they also grow rather quickly.
Colony size: Often found with over 3000 workers in the wild, expected to reach around 8000 in captivity.
Colony age: Seen lasting as much as 40 years in the wild (expects at least 10 years in captivity), actual maximum age a queen can reach is unknown. Extra (multiple) matings may be required for the queen to stay fertile for this long.
Founding: Semi-Claustral, the queen stops hunting when the workers arrive, but is very active until then, going as far as collecting multiple seeds and insect’s carcass then plugging up the hole to her lair for days.
Workers: monomorphic, size between the first and later generations varies greatly, this is also influenced by alimentation.
Nesting sizes: Starts small with a small outworld, can grow to enormous proportions as the colony matures. Upgrade nests as necessary for their current colony size. A destructive species resistant nest is recommended.
Feeding: Pogo can get away with only being fed seeds and water, which makes feeding them very simple and easy. It is possible to give a mature colony a large number of seeds, water, and not bother them for days on end. In the wild, Pogonomyrmex stores large numbers of seeds in their nest (dry areas) and carry the harder ones into the humid sections until they soften or crack open on their own. They also accept the normal proteins you’d expect from an ant colony, as well as sugars. They noticeably aren’t big fans of liquid sugars, and do not like honey as much as other ants. A workaround is to give them raw brown sugar cubes and drop a few drops of water on it, a few times per week to liquefy it. They prefers to have access to substrate to deal with liquids.
Hibernation: 15-18 degrees for 2 or 3 months after first stopping giving them food to stop their brood development. Hibernation can be skipped if kept warm and well fed.
Reproduction: During august and September.
Movement/behavior: Pogonomyrmex ants are medium speed and are what I would call an ‘Hyperscavenger’. They are known to destroy anything they can to find food or extra moisture. The ants will carry back anything that can be used as food to the nest and will use humid areas to re-hydrate possible food sources or dead insects. They are pugnacious ants and will attack tweezers and fingers when confronted, rather than running away. Their sting feels similar to a wasp sting, but weaker, causing light pain and a numbing sensation. In the wild, a worker out for food will not return to the nest unless she finds something and can walk large distances. Pogo are infamous for covering the glass of formicarium with debris to give them the ability to nest against it. Pogonomyrmex are bad climbers and are easy to contain, but this also means they detest nests that are made with flat surfaces. Anything they can shuffle in the exploration area will be messed with.
Workers: Yellow/brown to red/brown body.
Queen: Yellow/brown to red/brown body.
Males: Dark/brown body with a yellow/orangeish brown abdomen. They are similar to other myrmicinae males from above.
Workers: About 6.5 to 10 mm long, at maximum size, workers reach close to 85% of the queen’s size.
Queen: Up to 14 mm long, (11-14mm).
Males: about 9 to 12 mm long.
Varies wildly with heat, at higher temperature (30c) and with enough food, egg to fully grown ant takes less than a month.
Recommended for beginners: Yes, although they can be medium difficulty to start if the queen doesn’t have the best conditions, patience is required. Once the first workers arrive, becomes low difficulty and even one of the easiest ants to keep.
Some reliable seed sources are recommended at first, sunflower seeds for birds works well.
Temperature: 23-33c. Pogo are a heat loving species and thrives in temperatures up to 33c (indirectly), over this temperature they move the brood slightly off-centre of the heat source. A gradient of heat is best, so try to heat only a corner/part of the nest.
Humidity: at least 60%, up to 90% and more in some areas is required. Pogo love a good humidity gradient as they require a lot of humidity due to their high heat, but also dry areas to store seeds and dry insects, carcass, etc Larvaes will be kept at the highest humidity, especially early on. Too low humidity can lead to deformities in newly solidified workers.
Nest types: Soil-like floors are preferable for the humid areas, even in a test tube. Most material are acceptable for the outworld. Keep in mind Pogos will attempts to shred anything they can, and customize their nest with what they can find, including cotton. Flat surface to walk on can cause them some stress.
Formicarium accessories: Obligatory heat source (heat mat, heating cable or heat lamp). Substrate type: This species doesn’t climb well and any form of substrate or realistic setup in the formicarium and outworld is very helpful (a small coating of a mix of sand and dirt will really help them climb the tube out of nests or navigate through them). They will be contained by glass or plastic, with a little fluon (their grip improves with dirt, and they will actively attempt to make slippery surfaces easier to grip on).
Pogonomyrmex Occidentalis is a fast-growing large ant with a badass temper. They will be mostly nocturnal and overly careful at first, then they become balls of rage and confidence as their number grows. They start accepting more and more alien foods as their numbers and needs increases. They are easy to move, unlike many ants, and the trick to that is letting the old nest dry up then using cold (ice packs, etc) to make the old location unwelcoming. These ants will try and bite everything once, thus it is important to be careful what is given to them. I once gave them a charcoal piece covered in springtails, only to find half a charcoal piece and charcoal everywhere being used as substrate. Oh…and no more springtails.
Additional antkeeping information
A blank test tube with cotton is a suboptimal way to start a Pogo colony: The slippery floor will stress her, the constant light will cause her to panic, and the average humidity will not fully satiate her. The queen may use her poo on the glass to give herself better grip.
The nesting area needs to be dark, warm, and very humid (A small humidity gradient is great if possible, a bamboo tube works well for that). Consider using some dirt in the tube against the cotton, possibly pushing the cotton a little more (careful of flooding). Substrate is needed for the queen to feel comfortable; she may also use it to soak up sugar, liquids, or plug up the entrance. If a bamboo tube is used, ants should be moved before they break 30, as they can and will destroy the tube from the inside out and could cause eventual flooding.
A small outworld is recommended for the queen, as she will hunt (often at night to begin with) for any food she can get her hands on. Leaving some seeds (small pieces of sunflower seeds works great) around there works wonders. Keep in mind that raw seeds should be replaced under a week, as when molds do sets in, further seeds will rot much faster. Other seeds can be used, but it is strongly recommended to at least break them open, or into smaller pieces for large nuts like almonds.
Pogo are bad climbers, and you should avoid giving them pools of liquid, especially without substrate available for them to pile on it. They are prone to drowning, mostly due to them getting stuck in the liquid and having no grip to pull themselves out.
This also extend to vertical nest tubing. A small mix of soil and sand, applied carefully with a q-tip along the length of the tube, creates an easy to climb on surface for them. A small rock or hard to move object for them to step out of tubing on is recommended.
Seeds are their bread and butter, they can and have been raised fully and only with seeds and water. When the colony has enough workers, unopened seeds can be used (such a small budgies seeds mix), the workers will carry them in humid areas and open them up. Large nuts are still recommended to be at least partly crushed, otherwise the workers will spend days breaking down the large nuts. Their mandibles are quite powerful and there is little they won’t be able to break. Hard shelled seeds bigger than they can carry would only function if they could bring them to humid areas, so they are generally not recommended (unless already cracked open).
One of the most interesting aspect of Pogonomyrmex are their hyper-scavenger nature, one of their most interesting behavior is that they accept dried food and bring them to humidity sources to re-hydrate them, when able. Thus, they accepts a lot of food other ants ignore, and can be fed with dried insects mix (preferably once they are large enough).
When cleaning the trash left by the ants, you can use their difficulty climbing to your advantage. Angle something with a smooth surface over their nest and pour the trash over then tilt it, slowly picking off the workers who manages to hang on.
If you aim for a true naturalistic setup, Pogo are great for such a thing as they are very active and do not climb out of it easily, be careful of the materials used, however.
Pogonomyrmex can be habituated to light very well and even very early, but it is recommended to wait for the first workers to arrive first, as to not stress the queen. Brief bright light will not bother them much.
You can very well imagine Pogonomyrmex as a scavenger in a dry land, they will try to eat everything they see, and break down anything they find, in the search for food.
Workers will not sting instantly when they climb on you, as they are then exploring over attacking a target, they can be easy to pick or shake off. Tweezers are strongly recommended for any manipulations however, they will bite those.
I have been experimenting with dead pogo workers as a source of nutrients for other ants, with positive results so far.
The true difficulty of this species is space and housing, they are large, fast growing, and destructive little red monsters with no fears.
Diet & Nutrition
Note: A varied Pogo is a healthy pogo. It would be shorter to list the foods they do not accept.
Unlike most ants, Pogo aren’t as fan or sugar water and honey (possibly due to the fear of drowning) and will often cover such sources with substrate. Occasionally carrying small sugar balls to the nest. This causes them to easily empty a water feeder in an hour. They seem to enjoy raw brown sugar cubes, slowly re-hydrated with a few drops of water. Most of their carbohydrate needs can be otherwise/also handled by seeds.
Pogonomyrmex will readily accept a wide variety of foods and they can alternatively get carbs with unlikely sources, such as bread, flour, corn mullet, and oatmeal.
They seem to prefer putting substrate on fruits and then slowly dismantling them before throwing them in the trash.
Seeds give Pogonomyrmex most of the proteins they want, but a variety of nutrient sources create wonders in terms of growth and sizes.
Pogo are somewhat unique in the large number of protein sources they accept, a trait I am only aware in Tetramorium. They accept dried bugs (rehydrating them is still better), dead bugs, cheese, milk, fish flakes, fish pellets, etc I have on occasion fed them some meat or sausage as well.