Oligophagy refers to the eating of only a few specific foods, and to monophagy when restricted to a single food source

The term is usually associated with insect dietary behaviour. Organisms may exhibit narrow or specific oligophagy where the diet is restricted to a very few foods or broad oligophagy where the organism feeds on a wide variety of specific foods but none other.

Polyphagy, on the contrary, refers to eating a broad spectrum of foods. In the insect world it refers usually to insects that feed on plants belonging to different families.