(j FARMERS ' BULLETIN 933. 



during the remainder of the year. The fungi kill the insects only 

 after the tree has given up its vitality to furnish nourishment for 

 the insects' development. As a rule, when fungi are depended 

 upon as the only method to free trees from insect attack, the trees 

 are left in a weakened condition, often with much dead bearing 

 wood and sparse foliage, before the fungi succeed in temporarily 

 reducing the insects to a point where little damage follows. 



TIG. 4. A grapefruit heavily infested with both the Florida red and the purple scales 

 in all stages of development. Note that the scales form a scurf over the rind. 



SPRAYING COMING INTO GREATER FAVOR. 



Enthusiastic supporters of control by natural agencies contend 

 that it is more profitable to grow lower grades of fruit without 

 treatment than the better grades with treatment. Yet a system 

 of spraying for improving grove conditions has been gradually 

 adopted by men who, only a few years before the Bureau of En- 

 tomology began its work, depended upon fungi as the best all- 

 round method of control. This change from dependence upon 

 fungi to spraying with insecticides has come partly through 



