Cohabitation of insects and plants
The cohabitation of ant families and some trees is almost a typical example of mutualism, that is, mutually beneficial relations. Trees provide insects with a roof and a table, and they in turn drive away herbivores from them. However, recently it turned out that the ants are still cheating for the sake of breeding their own kind.
Scientists from Harvard studied the South American plant Cordia nodosa, on which ants of the species Allomerus octoarticulatus often settle. It turned out that insects do protect the tree, but at the same time destroy its flowers. Thus, they actually sterilize it, that is, make it sterile.
Ecologist Megan Fridrexon (Megan Frederickson) believes that in this way the ants increase their numbers. After all, the smaller the fruits and seeds, the more the plant is invested in its growth. And the more branches there are on the tree, the more space there is for living and breeding.
We will explain. A. octoarticulatus live in special cavities inside the tree (domatia), there they also “grow” and “milked” insects that produce sweet secretions.
To test her hypothesis, Megan traveled to Peru, where she selected several C plants.nodosa, on which there lived more friendly ants of another kind. Then the researcher cut the flowers of the tree (imitating the activity of A. octoarticulatus) and after a few months checked the number of those cavities. It turned out that on the pruned tree they became four times larger than on the ordinary one.
I am glad that the plant does not become barren forever: if the colonies of A. octoarticulatus leave a certain tree, it will be able to bloom again after a while, Frydson notes in his article in American Naturalist.
Often ants feed on the sweet nectar of plants and live in nests under thick bark. Such relationships allow insects to get a roof over their head and food, and the plant - biting defenders from herbivores.
The coexistence of ants and plants over many generations has created an interesting example of mutually beneficial, although not always honest, manipulation. This is reported by biologists from the University of London (Royal Holloway, University of London) and their colleagues from the universities of St. Andrew (University of St. Andrews) and Lund (LU).
In a study whose results were published in the journal Functional Ecology (the article can also be read in a PDF document format), the team of Dr. Nigel Raine describes the cohabitation and cooperation of ant families and acacias.
This type of interaction alone is not new. Another thing is interesting: as in any transaction, in a similar union of plants and insects, each of the partners seeks to get more benefits at the first opportunity.
According to scientists, some of the repellent substances produced by acacia are chemical imitations of pheromones that ants use to communicate. “We sprayed the substance over the ants to see how they would react. Insects immediately began to behave very excitedly and aggressively, ”explained Rhine.
Just as the ants themselves do when danger arises, the plant manipulates its occupants, using their signal system of smells and thus suggesting when to protect it. But that's not all.
Previously, it was a mystery to experts why during the pollination period, when the flowers of the plant are open and defenseless for external influences, the ants do not touch them. There are no natural barriers like slippery and sticky surfaces that prevent insects from entering the ground.
As scientists found out, the plant uses two approaches at once to solve this problem.First, it gives a kind of "bribe" to the ants living on it, dropping small doses of nectar on the stalks so that it eats, not reaching the flowers. In addition, the acacia uses odors that are unpleasant for insects, keeping the ants at a distance from nectar during the pollination period, just as it attracts them for its protection.
According to Rhine, such a carefully crafted system shows how long the ants and "their" plants developed together, guarding and controlling each other.
This is what ants can cause.
"Devil's Gardens" are mysterious sites in the Amazonian forests, where only one type of tree grows, and no other. The origin of such an unnatural "weeding" was found out by biologists from Stanford (Stanford University), having gone for this to Peru.
The name "Devil's Gardens" comes from the belief of local residents, who believe that the evil forest spirit of Chuyataki lives in these places.
Scientists, once in place, decided to check two versions. The first is the guilt of the Duroia hirsuta trees growing there. They could use chemicals to “ban” the growth of other plant species nearby. This phenomenon is known to biologists.
Another version is the guilt of the Myrmelachista schumanni ants, also called the “ants of the devil's gardens”, as they live on Duroia hirsuta stems.
It is the working ants, as it turned out, and carry out the selection of plants. They simply kill the green shoots of other species than Duroia hirsuta, injecting formic acid into their leaves as a herbicide.
As shown by experiments with planting rival plants in the Devil's Gardens - the attacked greens die in a day. Control landings outside the "responsibility" of the ants - flourished.
In this way, the ants give their favorite trees to grow freely, without competition, thereby expanding their homes.
According to biologists, the largest of the famous "Devil's Gardens", numbering 328 trees, has an age of 800 years.
And here is another interesting thing about ants: for example, the Largest ant in the world, but Ants are slave owners and the Ant is a kamikaze. In general, of course, scientists have proven that ants consider their steps and there is the Spiral of ants death.