Question 3 Ant Queens and Pheromones

Mike wrote to the “Consult-Ant” with a number of questions about ants. I am going to try to answer each one in a separate post. For the original list of questions and links to all answers, visit here.

3)      I’ve been meaning to catch an ant queen, but I’ve been curious about other methods of catching one. Are there ant pheromones that can basically attract queen ants to come out of the colony? I assume that each ant species would probably have their own type of pheromones, so I’ll have to find out which species I’m planning to catch, which leads me to the next question: Where can I get these pheromones? Can I synthetically make them on my own? What differentiates certain pheromones from another? Subtleties in molecular structure?

That’s an interesting idea, Mike, but it actually works in reverse. The queen produces pheromones to attract males during the mating flight (although some species have other signals, like harvester ant queens stridulate). Once she has started a colony, usually the pheromones she produces regulate the behavior of the workers, attracting them to her. She is the most important member of the colony after all. I guess it is possible that wafting an alarm pheromone into a nest might drive out the queen, but your chances of finding her amidst the other ants? I’m not sure.

Chemists have definitely synthesized pheromones for insects, usually for those with economic importance, for example gypsy moths. The chemistry is often quite complex. The chemical structure may vary by something as simple as chirality or as complex as being a totally different molecule.

If you want to catch a queen, nothing beats learning all you can about the life history of the species you are interested in and then going out when at the time of year when swarms occur (often depends on the weather) and look for mated queens. I find queens all the time because I’m looking for ants, and queens start their colonies where other ants are successful.

show-queen

Anyone else out there have any ideas for Mike?

Edit: In researching your next question I did find evidence that in carpenter ants, the males release a pheromone from their mandibular glands that signals to the female reproductives that it is time to fly from the nest and join the mating swarm. (Holldobler and Maschwitz 1965, as cited in LD Hansen and JH Klotz, Carpenter Ants of The United States and Canada). Although they would be unmated, that might be a way to entice them from the nest. The other problem I foresee is that the unmated queens would need to be physiologically ready to go on their mating flight or the pheromone wouldn’t work.

See the next post for more information on pheromones.

Question 2 Ant Undertakers

Mike wrote to the “Consult-Ant” with a number of questions about ants. I am going to try to answer each one in a separate post. For the original list of questions and links to all answers, visit here.

2)      I’ve noticed that ants carry pick up their dead and move them. I’ve learned that they do this to basically ‘take out the trash’ for sanitary purposes. But I’ve also noticed that these ants also carry their dead when they’re far away from any ant hole. So, referring to my other question, if it’s true that ants do take the solid food back to their larvae, then are these ants carrying their dead back to their larvae for consumption? Assuming ants are cannibalistic, which I’m not sure of.

Recently I photographed some clues that might shed some light on your ant carrying mystery.

carrying-ant

This Forelius worker is carrying another ant.

carrying-ant2

She carried it right back to the nest and dragged it in. Notice, however, the dead ant has two “nodes.” It is a worker of Solenopsis xyloni from a nearby colony. The area around the Forelius nest was strewn with Solenopsis parts.

Many ants will carry fallen foes back to the nest as food, as well as the enemy colony’s pupae, larvae and eggs. In that way, ants are indeed cannibalistic.

It makes sense to process and eat healthy enemy ants. It does not, however, make sense to eat dead ants from the home colony because they may be diseased or have parasites.  Worker ants do carry their dead nestmates to the refuse heap, as shown by the famous ant scientist, EO Wilson in the 1950’s. Wilson figured out that chemicals were involved in the recognition of dead ants, particularly oleic acid. When he dipped oleic acid on a healthy, living ant, her sisters still dragged her off the the ant graveyard. The ants was not allowed back into the colony until she managed to clean herself up.

For the EO Wilson story, visit ‘Hey I’m Dead!’ The Story Of The Very Lively Ant by Robert Krulwich

Finally, worker ants sometimes carry live ants as well.

Comments?

Question 1. Ant Digestion

Mike wrote to the “Consult-Ant” with a number of questions about ants. I am going to try to answer each one in a separate post. For the original list of questions and links to all answers, visit here.

Question 1)      I’m interested in the ant’s digestion process and its role in the colony. I’ve read that some ants, the fully mature ones that is, can’t digest solid food due to their narrow waists. So is it true that the ants would take the solid food back to the colony and give them to their larvae where, there, it is digested and converted into a liquid form? I’m guessing that the larvae have the enzymes to digest the solid food. But does this process apply to ALL ants in terms of species?

I actually tackled this topic to some extent in my post about ant larvae, but I’ll re-state some of the high points here.

Because the petiole is so narrow and constricted, ants do have a specialized digestive system. When an ant eats, the food goes into a special pouch called the infrabuccal pocket in its mouth, which acts like a food strainer. The infrabuccal pocket prevents large particles from continuing into the digestive system. Probably the size of the particle allowed through varies from species to species, but in the carpenter ant, Camponotus pennsylvanicus, particles larger than 100 microns are excluded from entering the alimentary canal . The liquid and tiniest particles that can move through the narrow petiole are sucked into a tube and pass through into a special reservoir in the gaster called the crop. The ant spits out the leftover bits that were too big to go through the food strainer. The rejected bits are called infrabuccal pellets.

Scientists have long known that the worker ants feed all solids to the larvae first for processing. The larvae were thought to chew up, swallow and predigest the food, using enzymes, as you guessed. The larvae then regurgitate it back to the workers to distribute throughout the colony.

Recently, however, researchers have shown that in one species of bigheaded ants (Pheidole) the workers actually place the food on the surface of the belly of the larvae in a special groove (larvae lay on their backs). The larvae spit out the enzymes onto the food, basically drooling on themselves. After a few hours, the workers come back and pick up the slime that results, feeding some of it to the larvae and taking some for themselves. According to videos of the larvae processing bits of fruit fly, the larvae very rarely sip any of the gooey liquid while the food is dissolving; they wait patiently until the food is done and let the worker ants feed them.

Probably the most surprising aspect of ant larvae is that not only do worker ants bring them food, but the larvae are often sources of food themselves. Certain species of ant larvae have special structures that allow the workers to access the internal body fluids (hemolymph), a sort of pump or “tap.”

The so-called Dracula ants take things a step further. These rare ants get their name from the fact that they cut holes in the sides of the larvae and suck out hemolymph. Although this sounds pretty gruesome, the larvae survive having holes bitten into them and later become workers themselves.

Another odd behavior of this group is that the workers carry the larvae to their food and place them on it, rather than carrying the food to the larvae, as most other ants do. For example, instead of cutting up a caterpillar or millepede into chunks and carrying it into the nest to feed the larvae, Dracula ants carry the larvae out to the caterpillar. Once they have fed, the larvae become food themselves.

If you think about it, the adult ant’s weird digestion system does work because adults don’t need a lot of protein for growth, they mainly need carbohydrates for energy. The same is true for some birds. The adult birds may drink sap or nectar, but feed protein-rich insects to their growing chicks.

Anyone else have anything to add?

References:

Gotwald, W.H, Jr. 1969. Comparative morphological studies of the ants, with particular reference to the mouthparts (Hymenoptera:  Formicidae). Cornell University Agricultural Experiment Station. Memoir 408.

Hansen, L. D., and J. H. Klotz. (2005). Carpenter ants of the United States and Canada. Ithaca, NY: Comstock Publishing Associates. This book has an excellent chapter on ant morphology.

Keiichi Masuko (1986). Larval Hemolymph Feeding: A Nondestructive Parental Cannibalism in the Primitive Ant Amblyopone silvestrii Wheeler (Hymenoptera: Formicidae). Behavioral Ecology and Sociobiology, Vol. 19, No. 4: 249-255

Keiichi Masuko (1989). Larval Hemolymph Feeding in the Ant Leptanilla japonica by Use of a Specialized Duct Organ, the “Larval Hemolymph Tap” (Hymenoptera: Formicidae). Behavioral Ecology and Sociobiology, Vol. 24, No. 2: 127-132

Keiichi Masuko (2008). Larval stenocephaly related to specialized feeding in the ant genera Amblyopone, Leptanilla and Myrmecina (Hymenoptera: Formicidae). Arthropod Structure & Development Volume 37, Issue 2: 109-117

D. L. Cassill, J. Butler, S. B. Vinson and D. E. Wheeler (2005). Cooperation during prey digestion between workers and larvae in the ant, Pheidole spadonia. Insectes Sociaux Volume 52, Number 4: 339-343.

Nectar and honeydew are good choices of food for adult ants.
Nectar and honeydew are good choices of food for adult ants.

Multiple Questions About Ants

Hello Consult-ant,

Thank goodness I’ve managed to stumble on this site; the information on other websites don’t quite provide the information I’m looking for. I think I may have a rather large amount of questions because I find ants just fascinating. Although, I’m not sure if it’s appropriate to ask these many questions, so sorry for the inconvenience. If it is inconvenient (which I highly think it is), then are there any books on ants that you’d recommend I can read from? And please, by all means, answer as conveniently as possible for you such as answering a few questions at a time. Any way would be appreciated. So, to my questions:

1)      I’m interested in the ant’s digestion process and its role in the colony. I’ve read that some ants, the fully mature ones that is, can’t digest solid food due to their narrow waists. So is it true that the ants would take the solid food back to the colony and give them to their larvae where, there, it is digested and converted into a liquid form? I’m guessing that the larvae have the enzymes to digest the solid food. But does this process apply to ALL ants in terms of species?

Edit: Answer Post about ant digestion

2)      I’ve noticed that ants carry pick up their dead and move them. I’ve learned that they do this to basically ‘take out the trash’ for sanitary purposes. But I’ve also noticed that these ants also carry their dead when they’re far away from any ant hole. So, referring to my other question, if it’s true that ants do take the solid food back to their larvae, then are these ants carrying their dead back to their larvae for consumption? Assuming ants are cannibalistic,which I’m not sure of.

Edit: See post about ant undertakers

3)      I’ve been meaning to catch an ant queen, but I’ve been curious about other methods of catching one. Are there ant pheromones that can basically attract queen ants to come out of the colony? I assume that each ant species would probably have their own type of pheromones, so I’ll have to find out which species I’m planning to catch, which leads me to the next question: Where can I get these pheromones? Can I synthetically make them on my own? What differentiates certain pheromones from another? Subtleties in molecular structure?

Edit:  see post about ant queen pheromones

4)      Besides making trails and setting alarms, are there any other kinds of unique pheromones? Such as, attracting the queen ant or inducing certain behaviors like digging.

See 5.

5)      The ant uses their antennae to pick up ant pheromones, so if that’s the case, then do ants necessarily ‘smell’ food if the pheromone is blown towards the ant’s way? Essentially speaking, can ants smell their way to food?

Edit: I combined questions 4 and 5 in a post about ant pheromones.

6)      So ants have pheromones they lay to provide trails to sources of food, but I’ve read somewhere that ants have memory. Can you explain more about that? A ‘leader’ ant would teach a ‘follower’ ant towards a food source. Is that true? with only certain species?

Edit: Hey, I remembered to answer this question.

7)      I’ve read a little about trophallaxis (I hope I spelled that right, because Microsoft Word does not help in scientific terminology), but I don’t see ants perform trophallaxis much. I was observing pavement ants though, so perhaps it has to do with the species. But my question is, do they perform it more underground, as in their colony? Or is it all because these ants weren’t hungry at the time? And what does an ant have to do induce another ant to perform trophallaxis? Some kind of touch communication by antennae?

Edit:  Ant trophallaxis is now posted.

8)      If I were to catch a queen ant, would it be recommended to feed her some protein as well as sugary foods like honey? I was thinking about this because I’ve read that the eggs and larvae would need protein to grow properly (I’m guessing for muscle development and such). So is peanut butter a good protein choice, in substitute of other insects? I’m worried that peanut butter wouldn’t have all the essential amino acids because peanut butter is an incomplete protein. But I’m not sure about ant development and physiology, so I’m curious.

Edit: See Feeding Ant Queens

9)      Ants(obviously) eat other insects, and I probably lack observation skills but do the ants also eat the exoskeleton also? Do they (or the larvae) have some way of digesting chitin? I did see that the ants pretty much leave MOST of the exoskeleton intact, and go for soft parts.

Edit: Can ants digest chitin?

10)  If the eggs, larvae, and pupae were placed in bad conditions, specifically temperature, for a short period of time, would they be harmed?

Edit:  Effects of heat and cold on ant larvae

11)  Are there some ant species that simply drink water and then other species that absorb it from the humidity of the air? Or do they all do both?

Edit: Ants do drink water.

12)  I’m going to be feeding my ants probably some form of sugary food, like honey. But I’m wondering if it is also good to mix the honey with some vitamin and mineral supplement. Are there any substances in typical dietary supplements that ants should not eat?

Edit: See Feeding Ant Queens

13)  If a colony with only one queen ant were to die, would she be replaced with another?Or does the colony die out. If she gets replaced, then are there always alates available to replace her at any time? Or are they only produced prior for the mating season, nuptial flight, and etc.? Is there any way of the colony knowing that the queen is about to expire, like some kind of special pheromone?

Edit:  And we finish with replacing ant queens.

Wow. I do have a little bit more questions. But, I think I’ve consumed A LOT of your time. I think I’ll stop for now. I truly appreciate your time thus far. As you can see though, I am VERY curious about ants, especially social creatures like termites or even dolphins. I’d also like to apologize if some of my questions were already answered elsewhere. So thank you again for your time.

Extremely big thanks,

Mike

Dear Mike,

You have asked a good number of questions. Rather than trying to tackle each on of them here, which would make a very long post, I’m going to answer each question in a separate post and then link them here as they go up. That might make it easier.

As for books, I’ve put a widget in the left sidebar of some popular ant books. I particularly recommend that you pick up a copy of Mark Moffett’s Adventures Among Ants, which I recently reviewed. I think you would enjoy it.

If anyone reading this has posts or links that they’d like to share about any of these questions, please let me know. I could use the help 🙂

-The Consult-Ant

(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.)