(Note: As I mentioned previously, I have been the “Consult-Ant” on the Leaping from the Box website. I answer questions about ants and ant farms. From now on I will post the answers here, and when Karen has time she will also post the answers on her site.)
Question: Hi, I am a reading teacher in an elementary school. We are reading a book about ants. My students wanted to know what would happen to an ant colony if their queen died. I was able to find the answers. One of the answers was that the workers would choose a larva or larvae to feed a special diet to enable it (them) to become a queen(s). What does that special diet consist of?
Is there any other way for an existing worker to become a queen if the colony's queen dies? Can she eat a special diet to stimulate hormones that would change her into a queen?
First of all, thank you for being willing to look for answers to your students' questions. I'm sure they appreciate your effort.
These are actually difficult questions, and scientists are still finding out some of the answers. The information you found about workers being able to rear a new queen is definitely true for honey bees. The worker honey bees feed the larvae (young grubs) destined to become queens a formula called "royal jelly." Larvae fed regular food turn into workers. The composition of royal jelly has been studied extensively, and you can buy it over the Internet.
Because there are over 12,000 different kinds of ants, however, how an egg becomes a queen varies considerably between species. Ants were long assumed to have the same food-based system as the honey bees, but now that research techniques are more advanced, it seems that at least in some kinds of ants the eggs laid by the queen are predestined to be either workers or queens. No matter how much food it is given, queen egg becomes a queen ant and a worker egg becomes a worker ant. This is found to be the case in harvester ants and big-headed ants (See references below.) When food makes a difference, such as determining whether a worker becomes a big worker (major) or not, it seems to be the amount of food rather than the quality.
In ant species with a single queen, generally the workers will not accept a new queen and the colony dies out when the queen dies. In ant species with many queens per colony, however, such as the Argentine ant, the workers may accept new queens. How many queens a colony will accept may be influenced by how highly related the workers are, as well as environmental factors.
As for a worker being able to become a queen, once again it depends on what kind of ant you study. In ants with a separate queen "caste," with a queen that is bigger and structurally different, a worker can never become a queen. Once a worker ant becomes an adult, it can not change its form. A worker ant does not have wings necessary for going on a mating flight, for example, and can not grow them. When the queen dies, because the workers are females they may be able to lay eggs, but the eggs are unfertilized and result in male ants.
Other ants are more like wasps. All the ants within a single colony look pretty much alike with no physically different queen, and one worker acts as a queen (it has a special name, called a "gamergate"). In this case, when the queen-worker dies, another worker can assume her role. The queen-workers' hormone levels do change and her sisters can detect the changes. One species with this type of queen-worker is the jumping ant, Harpegnathos saltator.
I know that is all probably as clear as mud. 🙂 Please let me know if you still have further questions. You might also be interested in the posts on answers to questions from fourth graders, and the Ant Facts or Fiction quiz.
And if anyone has more information pertaining to these questions or knows of more recent research, I would love to learn more.
Holldobler, B. and E.O. Wilson. (1990). The ants. Cambridge MA: Belknap Press of Harvard University Press.
A recent article in ScienceDaily about harvester ants.
Abstract about research on big-headed ants (Pheidole).