The Collaborative International Dictionary of English v.0.48:

Phytophagic \Phy`to*phag"ic\, a. (Zool.)
   Phytophagous.
   [1913 Webster]

WordNet (r) 3.0 (2006):

phytophagic
    adj 1: (of animals) feeding on plants [syn: plant-eating(a),
           phytophagic, phytophagous, phytophilous]