UTBREAKS OF INJURIOUS INSECTS, particu- 
larly aphids and thrips, are often serious handi- 
caps to the growing of vegetable and truck crops. 
These have been hitherto combated mainly by the 
application of contact liquid sprays, the one most 
commonly used being nicotine sulphate. Because of 
several objections to this method of control, how- 
ever, the practice of applying nicotine in a dust car- 
rier has recently been adopted to a considerable 
extent, especially in California, as well as in other 
States. 
This bulletin gives the reasons for adopting nico- 
tine dust and tells of what it is composed, the proper 
time and method of application, and the strength to 
use. Different types of dusting machinery are de- 
scribed, and the work for which they are best 
adapted is indicated. Information is given for the 
treatment of the onion thrips, cucumber beetles, the 
melon aphis, cabbage aphis, and pea aphis, and the 
possibility of the control of similar insects on other 
crops is mentioned. 
Washington, D. C. ; Issued September, 1922 
