This question is not well placed. It should be " a relationship between two organisms in which both benefit is called".
The answer is SYMBIOSIS
Explanation:
Living organisms tend to interact with one another in their natural environment. This interaction are of different types depending on the effect on the involved organisms. One of those interactions is SYMBIOSIS. Symbiosis is a relationship between two organisms in which both of the organisms benefit from one another.
An example is the relationship between the "CATTLE AND EGRET". The cattle provides food for the egret when they feed on the insect parasites on their body while the egret helps the cow get rid of detrimental parasites.
What the larva and pupa stages have in common is that both stages take place in water. This is where the insect evolves until it becomes fully grown and then leaves water.