GENEEAL KBMAEKS. 



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

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

 ral 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 

 cau 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 spray iug 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 ditch- 

 es, 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. 



The second, or lurua or worm state is the one in which 

 most insects do their greatest amount of injury, since it is here 

 that most of the growth and feei^ing takes place. Many insects 

 are injurious only in this larv^^tage, as our cotton-worm, cab- 

 bage worm, cut- worm, etc , and all other moths and butterflies. 

 Some exceptions to this rule are to be found, as in our grass- 

 hoppers and most beetles, that do as much damage in the adult 

 as in the larva stage in many instances. While again, the Rose- 

 chafer that does little or no damage in the larva stage, as an 

 adult, does much injury to our vineyards. The larva or worm 



