Hyperparasitoid

A hyperparasite is a parasite whose host is itself also a parasite. This form of parasitism is especially common among entomophagous parasites.

The term is used slightly more loosely to refer also to parasitoids (now in any case treated as one of six evolutionary strategies within parasitism) whose hosts are parasites or parasitoids.

A well-studied case of hyperparasitoidism is the small cabbage white butterfly (Pieris rapae). The P. rapae larvae are parasitized by the larvae of the wasps Cotesia glomerata and C. rubecula, both of which are in turn parasitized by the wasp Lysibia nana.

Jonathan Swift refers to hyperparasitism in these lines from his poem "On Poetry: A Rhapsody":

Hyperhyperparasites have also been observed (specifically, a fungus on a fungus on a fungus on a tree).

...
Wikipedia