346 Report of the Uepartmext ok Entomology of the 



in the center of the blossoms. If the thrips are immerous the 

 injured buds of pear trees become sticky with a brownish liquid 

 and cease to develop, while the blossom clusters have a stunted, 



shriveled and brownish appearance as if blasted. 

 With slight jarring the bud scales fall to the 

 ground in unusually large numbers, while the 

 dead blossom clusters usually adhere longer 



and slough off grad- 

 ually. In clusters only 

 partially injured the 

 petals may be small and 

 uneven in size, the 

 stems dwarfed and of 

 irregular lengths, and 

 the calyces and other 

 structures of the blos- 

 soms more or less blackish or brownish. The 

 leaves of the first-formed clusters are generally 

 dwarfed in size, crinkly or cup-shaped or other- 

 wise deformed, with the margins irregularly 

 broken and blackened. These deformations are 

 more or less in evidence on the trees throughout 

 the summer. The fruit setting on such clusters 

 generally has weak stems and falls prematurely. However, some 

 trees under circumstances not wholly imderstood may have the 

 appearance of being severely injured and withal show a fair 

 setting of pears. The effects of the attacks of the thrips on fruit 

 yields depend on the numbers of blossom buds destroyed. Dur- 

 ing the past season some trees on account of the severity of the 

 attack produced little or nothing, while on adjoining trees the 

 work of the thrips was not so extensive, being confined largely to 

 individual branches or portions of the trees, causing a very uneven 

 setting of the fruit. 



On cherries the adults injure the stems of the fruit during the 

 act of oviposition and the}'^ also produce discolored areas and holes 



Fig. 1. — Pear 



Thrips: Adult. 



(Much enlarged) 



