JBRARY 
PLANT BOARD 
January 1946 
E-680 
Unite a States Department of Agriculture 
Agricultural Research Administration 
Bureau of Entomology and Plant Quarantine 
THE USE OP DDT IF CON TROLLING FLEAS 
By H. E. Stage 
Division of Insects Affecting Han and Animals 
DDT, when properly formulated, has been found very effective in 
controlling several species of fleas. Its long* lasting or residual 
effectiveness is unique in the insecticide 1 field, and because of 
this property some flea infestations can be eradicated with one treat- 
ment. The number of treatments, however, depends upon "the manner and 
thoroughness of the application* 
Breeding Habits of Fleas 
In order to understand how DDT should be applied for controlling 
fleas, the general breeding habits of these insects must be under- 
stood . l/ Adult fleas must have blood to complete their life cycle, 
although they may live without it for several weeks. There is no 
true "sand flea" breeding in the sand without animals upon which to 
feed. Rather, there are dog fleas, cat fleas, rat fleas, chicken 
fleas, and dozens of other species, most of which will feed on a 
number of different kinds of animals. 
Most flea eggs are laid on the body of the host animal and are 
shaken off or fall to the floor or ground before the larvae hatoh. 
During its larval stage the flea lives on the debris in which it is 
found. At this time the flea is particularly vulnerable to DDT 
sprays and dusts j therefore, any attempt at controlling the insect 
should exploit this fact. After about 15 days the immature flea 
completes its development and immediately attempts to obtain blood 
from a warm-blooded animal. An opportunity is thus provided for 
killing the adult flea with DDT powder applied to the infested animal. 
i/ For a discussion of the habits and life history of fleas see 
•How to Control Fleas," U. S. Dept. Agr. Leaflet 152. 
