Formica, the Crossroads Of Diversity.

When it comes to ants, you will never find a more diverse genus than formica. Some nest in soil, others in rocks, a few in trees, and a couple in carfully constructed pine needle mounds. Some are scavengers, some are slavers, and some are farmers. Formica is very diverse, here in colorado, there is 68 species, more species than any other place in the world.

Slaving formica

Some Formica eat the brood of other Formica. while relatively rare most places. In Colorado, where I live, ants that slave Formica are relatively common. they are very interesting and are high maintenance species to keep as they constantly need access to brood of other Formica. there are some creative setups online. I personally don’t keep these when I catch them because finding Formica brood sometimes takes a while so I’ll just let most queens I see scurry past me. All slaving Formica is also parasitic, which makes them even more difficult to raise. But it is not impossible, it requires some more resources and creativity than most Formica, but that’s the challenge! This is a difficult species to keep, if you have a strong experience base you can be able to keep this species.  

A slaving Formica queen (Formica cf. ocustripes) . Photo Credit: Josiah Kilburn 

Regular formica

chances are, if you’ve been keeping ants for a while and you live in Europe or North america, you have kept Formica. Formica (and subsequently Polyergus because they only kidnap Formica) is a relatively easy to keep and very common genus. Formica is a nearartic and subtropical genus, the lowest it ranges is Indonesia, the highest is Alaska/Canada. Most species of Formica are found in the United States. In the united states, the most diverse population is found in my home state Colorado! They are one of the few winter loving ants. with most species building grass, soil, wood, or pine needle nests. Formica is the only genus of ants with species that build their nests entirely out of pine needles and sap. Other than these few species most do implement needles and bark into the entrance of the nest.

Formica ant preforming nest maintenance, you can see pine bark and needles in this picture. I think this is Formica cf. coloradoensis, but I am not sure. 
Photo Credit: Josiah Kilburn

Most Formica is parasitic. this is one of the few genus in which more species are parasitic than are fully-claustral. Although most Formica doesn’t raid other Formica, most queens do kill other queens to start their colonies. While they may be parasitic in the wild, these queens usually can get away being fully-claustral in captivity. For example, I have this Formica colony which I have observed queens being social parasites in the wild which I raised two queens in captivity. One of the queens got all her workers and then died, so I transferred her newly born workers to my other queen with brood and now I have a small colony of this species.

I apologies for the quality, this image was taken with an iPhone 8 and no lens clip through a scratched up test tube.
 Photo Credit Josiah Kilburn
workers of the Formica species mentioned above I apologies for the quality, this image was taken with an iPhone 8 and no lens clip through a scratched up test tube. 
Photo Credit: Josiah

Why Formica is losing diversity.

Formica, unfortunately, is being out-competed for resources by invasive pest/tramp species. Now why is this happening? Well pest species, and the environment around them are both changing. Now I’m not pushing some political agenda, believe what you want to believe. but climate change is happening, that’s just the facts. To what effect, however, is debatable. these changes do increase temperatures in places, making a habitat more hospitable to a species like Tetramorium immigransLinepithema humileTapinoma melanocephalumMonomorium minum, or Solenopsis invicta, all are species which are currently replacing, will replace, or have replaced species of Formica. But there is still hope left of correcting this.

Formica Cf. coloradoensis searching around it’s nest entrance
Photo Credit: Josiah Kilburn

But we can change this by keeping these pests in captivity, and eventually releasing native species to keep their population up. So try and protect your local ant fauna and save species like Formica coloradoensis along the way!

The wonderful world of pseudomyrmex

Pseudomyrmex is a species of ant that often nests in trees or twigs. because only 4 species are ground nesting, it is considered arboreal genus. They have large ovular eyes, one of their defining features, the other being their length, they are at least 1.5 times as long as they are wide. In the central and south american tropics there are species that have symbiotic relationship with thorn acacia trees. In most cases Pseudomyrmex live in hollowed out twigs. the highest north they are found is Pseudomyrmex apache northern California. there are many different types of Pseudomyrmex from many different habitats, they are very fun ants to keep They are only found native in the Americas. Here’s an overview of some commonly kept species.

Pseudomyrmex pallidus

Pseudomyrmex pallidus is a species of ant found in deserts of North America They nest in twigs and sticks they hollow out. the queens are usually 7-8 mm and the workers are 5-7 mm length. They are one of the most polygynous species in the world, with upwards of 22 queens per small twig. Unlike Argentine ants or other extremely polygynous ants they don’t ever cull queens. they are translucent orange in color and have large, black, ovular eyes. In captivity tend to be picky when it comes to food, mine only eat roaches, meal worm beetles, and melanogaster fruit flies, however they may also eat curly winged flies, other beetles, and spiders possibly. They

Three queens of Pseudomyrmex pallidus this species is highly polygynous, more so than Linepithemahumile. This is an original photo.

have their nuptial “flights” in July but they mate just outside of the nest. the alates have wings but choose not to use them most of the time, however sometimes the queens fly to different locations to spread a colony, although most return to the nest after mating. they will mate in captivity and are a fascinating species to keep as the colony growth is only limited by the food provided. they grow slow usually taking about 4 months to develop at 33 degrees Celsius, seven at 21 degrees Celsius. They cant tolerate humidity well at all.

Pseudomyrmex spincola and other simbiotic Pseudomyrmex

These ants form simbiotic realationships with the trees they nest in Acacia trees. The Pseudomyrmex benifit from the beltian bodies produced by the tree for the ants. Also, they get prey in the form of the tree’s pest insects. The Acacia tree also benifits from this exchange, by gaining protection from predators, vines, and pests. These ants, however rare, are sometimes kept by hobbists, mostly in south america. They are kept in a setup with the trees they inhabit these trees are small trees so they don’t use much space. they require high humidity. 

A Simbiotic Pseudomyrmex worker, this is an unusual species because it nests in cecropia trees similar to Aztecha these ants also forage outside the area of the tree. This is an original photo.

Similar to Aztecha there are species of ants that nest in cecropia trees. for those unaware, cecropia trees are a fast growing, tropical trees that are common in south america. the ants that nest in them nest in the young growing trees. since these trees are fast growing they have no defenses for protecting themselves. the young trees have chambers that many other pests take advantage of. the ants nesting in the trees go inside these burrows and eat their inhabitants. also they go out and forage on other foliage. these ants are usually kept in custom wood setups. they require high humidity.

Pseudomyrmex Grascillis

This species spans from southern united states to northern argintina. they require high humidity and are monogyne. They usually live around humans, in windowsills and whatnot. they are found nesting in wood in the wild. this is one of the most adaptable species in this genus as it can accept normal ant setups. they are a very aggressive ant towards prey in the wild and captivity.

Pseudomyrmex grascilis queen credit:

They can be kept in acryllic nests, natural twig nests, ytong nests, and plaster nests. they develop faster in 26 – 32 degrees celcius. they normally have their flights early in the season march-july. the queens can be reared in test tubes like other ants.

What did I miss?

Nobody’s perfect, I included a few of these species, there are many similar to the ones above. Do you have a pseudomyrmex colony? If so, feel free to comment about it below. I will add it to this post and credit you! Also please note, that Tetroponera is not Pseudomyrmex although they are in the same family. I plan to do a separate post about Tetroponera as many different species of them are kept as well. More images of different species can be found on alex wild’s website . If you have a soil nesting Pseudomyrmex, please notify me! They are extremely rare and I would love to credit you in a separate post!