140 



OAKDESI^G FOR THE SOUTH. 



care should be exercised when purchasing trees to buy 

 only from those nurserymen who are known to be relia- 

 ble, and who are provided with satisfactory bills of health 

 signed by well-known entomologists. 



Messrs. Howard and Marlett, of the Division of Ento- 

 mology of the United States Department of Agriculture, 

 have made extensive experiments with the various 

 methods recommended for the destruction of this insect, 

 and their studies concerning the life history of the scale 



Fig. 50— San Jose Scale. Male adult, greatly enlarged. 

 Howard, Div. Ent. U. S. Dept. Agri. Cir. 3. 



have been so full and complete the summary made by 

 them is given. The illustrations are also taken from the 

 publications of these entomologists: 



" The scale is not readily detected by the casual ob- 

 server, and consequently often remains unnoticed until 

 the death of the tree calls attention to it. Unfortunately, 

 it multiplies rapidly. Each adult female continues to 

 give birth to living young for a long period (six weeks), 

 and there are several (probably four) generations each 

 year. It infests the stems, twigs, leaves, fruit of nearly 

 all deciduous trees, and is extremely difficult to kill. The 



