36 



Figures 12, 13, 14 and 15, were kindly loaned by the Mis- 

 sissippi Experiment Station. 



The discussion of the life history of the insect is given 

 only in so far as it is important that the farmer should 

 know it. 



In view of the fact that the edition of bulletin number 45 

 on Injurious and Beneficial Insects has long since been ex- 

 hausted, and that the demand for it still continues, on ac- 

 count of the general remarks, insecticides and machines for 

 applying the same that it contained, I have here repeated, 

 with some additions and omissions, that portion of Bulle- 

 tin 45. 



GENERAL REMARKS. 



In order to arrive at the best results in combatting insects, 

 it is important that we should understand at least the gen- 

 eral life history of the insects in question, that we may thus 

 know at what stage in its development means can best be 

 taken to destroy it. Some insects can best be fought in the 

 egg stage, others in the larva or worm stage, a few in the 

 pupa stage, and still others in the adult stage ; while many 

 can be controlled in two or more stages. To arrive at this 

 in a scientific way forms one of the great problems of the 

 economic entomologist. 



The larger number of our insects have four well defined 

 stages of growth. The first is known as the egg state and of 

 course in itself can do no harm. In a few cases these eggs 

 are deposited in clusters or groups and in such a way that 

 we can gather and destroy them, or when this is not 

 practicable, they can be killed by spraying them with kero- 

 sene emulsion or soda and caustic soap. 



Many insects winter in this egg stage as well as in the 

 pupa or in the adult state, and since they frequent sheltered 

 places, as leaves, rubbish and brush along fences and ditches, 

 etc., it becomes important that all such useless material be 

 gathered and burned every fall, thereby destroying many 

 insects that otherwise would appear the following spring. 

 Hence clean farming is one sure road to success. 



