Is a parasite

any organism that is not an autotroph or detritivore must be a parasite.

include animals feeding on plants (herbivores).

Herbivores don't fit in very well to classification of macroparasites and predators (microparasites work the same way for plants and animals, and there are no plant parasitoids).

Herbivory as a form of parasitism.

Both beetle and giraffe benefit from an interaction with the tree

(b) The tree suffers from the feeding of both the beetle and the giraffe

i) the beetle is small, with fast population growth, and the host harbors many individuals (macroparasite).

ii) the giraffe doesn't fit into our categories of macroparasite or predator at all because it does not live in the tree.