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An Overview of the Symbiotic Relationship Between Aphids and Ants

Symbiotic Relationship Between Aphids and Ants
Aphids and ants share a mutually beneficial relationship. Such an interaction can be called a symbiotic relationship. This ScienceStruck post gives you some more information on the same.
Amita Ray
Last Updated: Sep 25, 2018
It is a term used to define positive interactions between ants and other organisms like plants, fungi, or other insects.
Symbiosis may be defined as the close interactions between two or more different organisms, such that all the organisms in the association are benefited from each other. Such a relationship is called a symbiotic relationship and is demonstrated by a number of organisms.
Ants And Aphids
The relationship between aphids and ants is symbiotic, which is observed across various geographical niches. You might find these aphids and ants on your rose bush, tomato plant, hibiscus shrub, tulips, lilies, etc.
Ants are one of the most common insects, and there are more than ten thousand species of ants present worldwide. These are ground dwelling, social insects that show several unique capabilities. They are usually found underground and sometimes under logs. They feed upon small insects, dead insects, nectar, or honeydew.
Macro Of Black Worker Ant
Perhaps, one of the most fascinating thing about these organisms is how similar the behavior of these tiny beings is to that of humans. They live in well-structured colonies consisting of males, females, and the queen; they show division of labor.
Forest Ant
Another interesting feature of ants is that they communicate with each other with help of certain chemical secretions; sometimes they communicate with the help of sounds.
Aphids on leave
Aphids are sometimes called plant lice. There are more than four thousand known species of aphids. These are tiny little insects that are found on the stems and the underside of leaves; they are usually hard to detect. These insects cause maximum damage to plants and bore into their stem in order to feed on plant sap.
Relationship Between Aphids and Ants
The relationship between aphids and ants is said to be analogous to humans rearing cattle. In which both individuals derive some benefit from each other. Here, the aphids provide a source of nutrition to the ants, and the ants provide protection in return.
Benefits Provided by Aphids
Aphids of different sizes
❖ Aphids pierce the vascular system of the plant and feed on a large amount of plant sap―a source of nutrition that is high in sugar content.
The excess sugar and amino acids is given off by the aphids as secretions from their alimentary canal in the form of honeydew. Ants can stimulate the production of honeydew by simply stroking the abdomen of the aphids with their antennae.
❖ Aphids are capable of reproducing through parthenogenesis. Parthenogenesis is a type of asexual reproduction in which an individual develops from an unfertilized egg.
The female aphid is capable of laying a large number of unfertilized eggs and a large number of wingless female aphids arise from it. Old and other aphids that do not produce enough honeydew are eaten by ants and form a source protein for ants.
Benefits Provided by Ants
Ant tending aphids
❖ Ants tend to aphids by protecting them from their natural predators. Ideally, aphids produce a particular pheromone to alarm other aphids about the presence of a predator.
This pheromone may be taken up by the ants, and they may attack the predator. In addition to this, they carry the eggs of aphids to their nest during winters, and provide a warm and moist environment that help to keep the eggs viable.
❖ Ants eat excess of honeydew that may be generated, and therefore, provide protection to the aphids from infestation by fungi.
❖ When predator larvae are placed near aphid colonies, ants protect the aphids by attacking the larvae. Another interesting fact about the aphid-ant relationship is that when lycaenid butterflies lay eggs near a colony of aphids tended by Myrmica ants, the ants carry the caterpillars to their nest.
These caterpillar are fed so that they too produce honeydew (yet another symbiotic relationship!) These caterpillars later morph into adult butterflies and leave the nest.
❖ Infestation by aphids may cause the crops to wilt, mottle, or die (due to the plant virus that they may carry or the toxin present in their saliva). In such cases, the ants carry the aphids to a new host plant and thus, help in preserving them.
More Interactions Between Ants and Aphids
Ant shepherding aphids
❖ Ants produce tranquilizers through their feet to subdue the aphids, reducing their speed only to a third.
Sometimes, ants clip the wings of the aphids so that they do not scatter easily. They may also produce certain chemicals that can prevent the proper development of wings in aphids.
❖ Despite this, the interaction between them seems to be favorable as the population of aphids increases with the increase in the number of ants. It is also seen that the content of trisaccharide, melezitose is increased in the honeydew produced by aphids that are tended by ants. This indicates that there is a positive interaction between the two organisms.
Aphids may be specific for their host plants, this may lead to the production of only a particular type of honeydew. As a result, only a few ants may tend to such aphids, giving rise to a highly specific symbiotic relationship.