The Collaborative International Dictionary of English v.0.48:

Flea-beetle \Flea"-bee`tle\, n. (Zool.)
   A small beetle of the family Halticid[ae], of many species.
   They have strong posterior legs and leap like fleas. The
   turnip flea-beetle (Phyllotreta vittata) and that of the
   grapevine (Graptodera chalybea) are common injurious
   species.
   [1913 Webster]