The Collaborative International Dictionary of English v.0.48:

Stridulate \Strid"u*late\, v. t. [See Stridulous.]
   To make a shrill, creaking noise; specifically (Zool.), to
   make a shrill or musical sound, such as is made by the males
   of many insects.
   [1913 Webster]

WordNet (r) 3.0 (2006):

stridulate
    v 1: make a shrill creaking noise by rubbing together special
         bodily structures; "male insects such as crickets or
         grasshoppers stridulate" [syn: stridulate, clitter]