Answer:
The type of adaptations exhibited by both organisms depends the effects each exhibited on the other.
When natural selection acts on the variation passed from generations to generations in a population,the organism involved are best fitted to survive in their habitats.The Ability of species of organisms to be best fitted against the selective pressure,so that it is naturally selected in the population is called adaptation.It is one of the driving force of evolution.
in this scenario the caterpillar,is camouflage by its green color,which blend with that of the leaves.And therefore ensure the escape from the predators e,g birds,spiders,reptiles This is an example of structural adaptation.Since it is the structural characteristics of the caterpillar that adapted it to its environment.
Likewise in the case of the plants,despite harbouring the caterpillar it ensures it does not destroy it physiological make up,by releasing chemical substances to keep away the organisms.This is called physiological adaptation,because certain biochemical substances are diffused by the plants in response to the caterpillar (stimulus), to keep off the organisms away,to ensure the survival of the leaves.Since physiology is the study of function of an organisms,changes in biochemical and cellular reactions must be responsible for the biochemical substances produced.