Pheidole bicarinata
Abstract
Pheidole bicarinata is one of the most widespread and successful species of Big-Headed ants in North America. Being from the genus Pheidole, itself one of the most diverse and successful genera of ants in the world, they are infamous for their major subcaste equipped with massive, muscular heads with large mandibles, utilized for ripping apart food and colony defense. It is native to every region of the U.S. except New England, the Pacific Northwest, and West Virginia (it likely is present in WV, as it is surrounded by native states, it just hasn't been recorded there yet). Workers are 2mm in length, majors are 3mm, and queens are 5-6mm.
Notably, this species was the subject of a study conducted by Diana E. Wheeler and Frederick Nijhout on how hormones administered during the larval stage affects a worker's subcaste, whether it will be a major or a minor. This hormone is called methoprene, or the 'juvenile hormone'. Interestingly, the pheromones of the adult majors suppress the development of more majors, especially when the majors serve as nurses to the larvae. The minors need to override these major pheromones by flooding the larvae with methoprene.
A key attribute which makes these ants so hardy and widespread is their adaptability to nesting environments. In the desert southwest, the species can nest in both deserts and forests, and in the eastern U.S. they can be found in open areas, from fields to lawns and golf courses. They aren't picky about where in those environments they nest either. Nests can be found under stones, wood, and cow dung, though they do just as well in the middle of open fields, making noticeable crater nests scattered throughout the landscape. Regardless, the species prefers well-drained soil with a high clay content.
P. bicarinata is omnivorous, readily accepting sugary liquids, feeder insects of all varieties, and more notably grains. They enjoy kentucky bluegrass, dandelion, and primrose seeds, as well as nuts. All three food groups should be provided in ample supply.
These ants are as hardy in captivity as in the wild. They prefer higher temperatures, above 82F/27C, and if provided that one condition along with food they will flourish, reading several hundred workers in their first year. Colonies tend to max out at 2-3 thousand workers somewhere between their 2nd - 4th growing season (if everything goes smoothly). The prefer their nests to be humid and thrive in test tube setups. Queens are fully claustral and monogynous, though colonies can found via pleometrosis, when queens cooperate during the founding stage and then kill each other (or have the workers do it for them) around the time nanitics arrive. They do not sting, and their bite is negligible. Due to their small size, these ants can escape quite easily, prompting the need for extremely tight and secure setups.
Nuptial flights occur from June to August, with the highest concentrations happening in July, then June. According to AntWiki, in Colorado males were found in the nest in early July, signifying their intended flight time.
Resources
Journals:
As you can see, journals on this species are few and far between. The only truly in-depth one I could find was ANTdrew's, which is amazing. Worth the read.
I hope this journal helps change that. Too many people keep this species for it not to be well documented.
Articles:
Soldier determination in Pheidole bicarinata: Inhibition by adult soldiers - ScienceDirect
Care Sheet - Pheidole bicarinata - Ant Care Sheets - Ants & Myrmecology Forum (formiculture.com)
Queen Ant Spotting/Mating Chart - General Anting - Ants & Myrmecology Forum (formiculture.com)
AntFlights.com - Pheidole bicarinata nuptial flight stats
Common Big-Headed Ants (P. bicarinata) | Stateside Ants
Pheidole Bicarinata - Buckeye Myrmecology
Pheidole bicarinata (Big-Headed Ants) Care Guide: – The Ant Vault
Update 1
October 14, 2024
The BRIGADE
I've always had a fascination for polymorphic ant species. As a kid, I would sit crisscross on the ground glued to my iPad binging AntsCanada videos for hours. My favorite colony was his Carebara diversa colony due to their extreme polymorphism. Naturally, Pheidole has always been some of my favorite North American polymorphic ants. I practically lusted for the trimorphic species such as P. rhea. Unfortunately for me, even the adaptive and hardy P. bicarinata has a hard time finding suitable nesting environments in Sioux Falls where I live, even more so with the expanding Tetra invasion. Despite loving open areas, the species is not at all common in eastern South Dakota, likely due to the soil being too rich. Great for farming, horrible for P. bicarinata. I have never seen a colony in person, though Ants4Fun once told me about a population in a small sandy area in an area north of Sioux Falls which he didn't elaborate on. Ants_Dakota also knows of a substantial population at the Lewis and Clark Recreational Area near Yankton, SD, though that is over an hour away, and we have not yet had the chance to see their local flight patterns (aka I don't want to drive down there just to find nothing).
I would have likely attempted to catch a flight despite the inconvenience next season or the season after that, though I had a more immediate concern: winter is coming. The only ants I had to keep me sane while the rest hibernated were 3 Tetra colonies. They are fun and fast growing, but in the end they're just Tetras. I would be bored out of my mind. There's only so much I can say in Tetra Trek! So, I made some impulse buys to get me some emotional support ants. I bought a couple Pogonomyrmex occidentalis colonies from Utah Ants, and then decided to try my hand at one of my dream species.
These lovely ladies came from Buckeye Myrmecology. I've been trying to buy from different stores recently. I've bought Pogonomyrmex from TarHeelAnts in the past, parasitic Lasius and Crematogaster from Stateside Ants, Monomorium from Atlantic Ants, and Camponotus and now Pheidole from Buckeye Myrmecology. I do not want to play favorites, as Ants_Dakota and I are working on (THIS CLASSIFIED INFORMATION HAS BEEN CENSORED BY WILDERNESS ANTING, LLC. TO BE DISCLOSED AT A LATER DATE) and that could hurt our operations. Can't have that, can we?
I received this colony on October 10, 2024. To my surprise, upon opening the package there was a massive roach in the box feasting on the corn starch packing peanuts. It was promptly fed to the Tetras. After dealing with the roach, I took a look at the colony itself. The colony was healthy with 11 workers, a pupa, 2 larvae, and a small cluster of eggs. The pupa has since eclosed. I then took the opportunity to move them into a Por Amor large cryptic insert by taping the test tubes together and exposing the old tube to light. I quickly found out how active and quirky these ants are, as they immediately moved into the insert, no questions asked. Many other species I've kept are quite stubborn when it comes to moving.
However, I did not have an outworld for them. No worries, as Ants_Dakota and I had already planned a massive outworld building festival the coming weekend. We finished our outworlds yesterday, and today I moved them in and put them on heat. Almost as soon as I laid the test tube down, multiple workers came out of the nest and commenced an expedition to chart their new home, which they accomplished in like 15 minutes. Ever since then between 2-4 workers have been strolling about the outworld at all times. I fed them some honey and a superworm head, which they gladly accepted. I will feed them seeds tomorrow. These ants are bold, and even at their small size will send a large percentage of their worker population to feed right in the open. I can only imagine how a large colony with majors would behave.
I named this colony The BRIGADE because it sounded cool and to create an alliteration with bicarinata. When I researched the meaning of the word, however, I found more meaning and fell in love with the name. A Brigade is a military formation with 3,000 - 5,000 soldiers. Considering this is actually around their max colony size and they're known for their soldiers, this fits perfectly. Another potential meaning is derived from fire brigades, the old term for fire departments. Their reddish coloration matches that theme, and their majors look quite muscular and burly, like firemen. Either definition suits them exceptionally well.
Their outworld. The bottom is grout layered with white beach sand meant for gerbils. I'm quite proud of how this turned out. A worthy prototype for (THIS CLASSIFIED INFORMATION HAS BEEN CENSORED BY WILDERNESS ANTING, LLC. TO BE DISCLOSED AT A LATER DATE), wouldn't you say?
The first worker emerges to explore a strange new world.
A brave prospector finds rich honey deposits.
Hark, what beast hast been slain here?
I will not be hibernating this colony and will continue to update throughout the winter. Next season, if I end up finding any, I will record the founding process on this journal as well. If I find a lot, I may even apply for (THIS CLASSIFIED INFORMATION HAS BEEN CENSORED BY WILDERNESS ANTING, LLC. TO BE DISCLOSED AT A LATER DATE) and start (THIS CLASSIFIED INFORMATION HAS BEEN CENSORED BY WILDERNESS ANTING, LLC. TO BE DISCLOSED AT A LATER DATE). The possibilities are endless!
Edited by RushmoreAnts, March 7 2025 - 7:37 PM.
