feeding on a single type of food

In entomology, a monophagous animal is an animal that specializes in a single food plant. A strictly monophagous animal is of course limited by its food conditions and is often a rare species if its food source is limited quantitatively or geographically. If the food source of a monophagous animal is a species that is of economic importance to humans (and is therefore cultivated systematically or on a large scale), then such a monophagous animal usually reproduces calamitously and is perceived by humans as a pest. In monophagous species, co-evolution often occurs.

Monophagy is represented in some species of phytophagous insects; among beetles, monophagous species appear, for example, within the families of leaf beetles and weevils. A specific case of a monophagous predator is the endemic species of spider Ammoxenus amphalodes from Africa, which feeds on only one species of termite.

According to the number of food plants, we divide insects into polyphagous, oligophagous and monophagous species.