. . . . . . . . are substance, which make the plant distasteful to the insects feeding on it.

Solution (By Examveda Team)

Antifeedants are substances, which make the plant distasteful to the insects feeding on it.
Antifeedants are organic compounds produced by plants to inhibit attack by insects and grazing animals.
These chemical compounds are typically classified as secondary metabolites in that they are not essential for the metabolism of the plant, but instead confer longevity.