sawfly

from WordNet (r) 3.0 (2006)

sawfly
    n 1: insect whose female has a saw-like ovipositor for inserting
         eggs into the leaf or stem tissue of a host plant

from The Collaborative International Dictionary of English v.0.48

Sawfly \Saw"fly`\, n. (Zool.)
   Any one of numerous species of hymenopterous insects
   belonging to the family {Tenthredinidae}. The female usually
   has an ovipositor containing a pair of sawlike organs with
   which she makes incisions in the leaves or stems of plants in
   which to lay the eggs. The larvae resemble those of
   Lepidoptera.
   [1913 Webster]