The Collaborative International Dictionary of English v.0.48:

Mucivore \Mu"ci*vore\ (m[=u]"s[i^]*v[=o]r), n. [L. mucus slime,
   mucus + vorare to devour.] (Zool.)
   An insect which feeds on mucus, or the sap of plants, as
   certain Diptera, of the tribe Mucivora.
   [1913 Webster]