Monday August 21, 2017 Q&A

Winged ants swarm together in flight because :

Réponses

1 The colony is preparing to migrate

2 They’re in battle with a neighboring colony

3 They’re seeking a once-in-a-lifetime opportunity for sex

 

Once in a life time! Really.

The swarms of flying ants we see each summer are known as nuptial flights, where winged male ants called drones and much bigger virgin female queen ants, also winged, mate together. As they flutter their wings, the male seeks to latch onto the female and inseminate her. Copulation begins and mated ants fall to the ground.

Depending on the species, the future queen copulates with one or many male ants, usually from other nests, during nuptial flight. She uses the sperm to start a new colony and keeps stores of the sperm in her abdomen for up to 30 years.  She removes her wings and uses the resources that were once her flight muscles to feed her first young, and then devotes the rest of her existence to laying eggs for her colony. This means that ant queens have but one day of romance before a lifetime of hard work.

The male ant, however, often dies soon after the nuptials. In ant societies, the male ant’s only job is to inseminate future queens. “The male ant may physically die, but he actually lives on from a genetic point of view in the form of sperm stored within the queen,” says biologist and ant expert Adria LeBoeuf.

How do the ants know to swarm on that particula day? Scientists do not yet have a definite answer. They have observed that humidity, heat, and season are all important, but that conditions vary from one species to the next. Somehow ants in areas where it is always humid still manage to coordinate their mating flights!  Generally, swarming behavior needs to be coordinated across colonies to make sure different colonies can mate. While a lot of communication happens within colonies about foraging and where to build a nest[2], or even how many new workers the colony needs to bring into the world[3], it is likely that the cues ants use for a mating flight influence each winged ant independently.

Ant colonies have sex the same way trees do[1]. Once a year, usually on a humid and hot day in the summer, they send out swarms of males (pollen) and unmated queens (seeds). The “seeds” are fertilized by the “pollen” of neighbors and start new “trees”.

As for migration and battles, LeBoeuf says, “Ant colonies usually stay in one place, and if they do move house, they do it walking. The same is true for battles. Ants are very territorial and they often battle against other colonies, but they do it on terra firma, and it’s never the winged ants that are on the front lines.”

 

[1] http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.12617/full

[2] http://www.sciencedirect.com/science/article/pii/S2214574514000935

[3] https://elifesciences.org/articles/20375