Bui. 173, U. S. Dept. of Agriculture. 



Plate IV. 







Fig. 1.— Unsprayed Portion of Prune Orchard in which Blossoms are Com- 

 pletely Destroyed by the Pear Thrips. (Original.) 



Fig. 2.— Sprayed Portion of the Same Orchard, Showing Trees in Full 

 Blossom. (Original.) 



INJURY TO PRUNE ORCHARD BY THE PEAR THRIPS. 



