Oligophagy

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

[2] 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.

[3] Polyphagy, on the contrary, refers to eating a broad spectrum of foods.

The diet of the yucca moths is restricted to the developing fruits of species of yucca[3] while the sea hare, Aplysia juliana (Quoy & Gaimard), is found on and feeds only on a single alga, Ulva lactuca (Linnaeus) in east Australian waters.

Conversely the migratory locust may be said to be broadly oligophagous or even polyphagous.