INSECTS 183 



eggs per individual, there would be one hundred times two 

 hundred, or 20,000 eggs; 10,000 of these might be females 

 to begin the second generation. If these females should 

 each deposit two hundred eggs, there would be 2,000,000 eggs, 

 1,000,000 of which might be egg-laying adults to begin the 

 third generation, etc. 



It has been found that a new generation of potato beetles 

 occurs once each fifty days during the growing season. The 

 possible descendants of one pair of potato beetles have been 

 estimated at 60,000,000 for one season. Fortunately no 

 kind of insect ever reaches its possibilities of reproduction. 

 If it did, the world would soon be so filled with insects that 

 there would be no room for other life. As a matter of fact, 

 owing to various difficulties such as scarcity of food, diseases, 

 insect parasites, birds, etc., the number of insects that get 

 a chance to live is very small compared with the number 

 that might develop if all conditions were favorable. 



Growth of insects. Rapidity of growth is perhaps the 

 most important fact to be considered in relation to the damage 

 done to crops by insects. For instance, some caterpillars 

 which reach their growth in thirty days increase in size 

 10,000 times. At this rate, an infant weighing eight pounds 

 would weigh as a full grown man 80,000 pounds, or forty tons. 



In order to make such a rapid growth, insects must eat 

 large quantities of food. It is not uncommon for a cater- 

 pillar to eat twice its weight in leaves in one day; often the 

 rate of eating is greater than this. For example, one of our 

 large caterpillars consumed in fifty-six days one hundred 

 and twenty oak leaves, amounting to three-fourths of a pound. 



Insects are able to meet adverse conditions. Another 

 important fact of insect life is that they usually have a way 

 of meeting adverse conditions. This bears on the question 



