12 



CIRCULAR 3 6 5, U. S. DEPARTMENT OF AGRICULTURE 



creamy emulsion. When the mixture is heated and pumped as here 

 directed, no free oil should come to the top on cooling. This makes 



Figure 7. — Characteristic feeding of the larvae of the twice-stabbed lady beetle on 

 female camphor scales on camphor-tree twigs. Note two empty pupa cases on twig 

 at left. Enlarged 2 times. 



a stock mixture containing about 60 percent of oil by volume, and 

 is diluted for use according to the concentration desired. 



