THE ENEMIES OF PLANT LIFE 



tion has done its uttermost. Millions of dol- 

 lars have been, and are being, expended. 

 Costly apparatus and large numbers of work- 

 men have made up this expense, to say noth- 

 ing of millions of dollars lost through ruined 

 crops and orchards. In the state of Massachu- 

 setts alone it is estimated that eight millions 

 of dollars have been spent in unsuccessfully 

 combating a caterpillar. The whole gamut 

 of chemistry and invention has been run, and 

 while good has resulted from some of the 

 many washes, sprays, fumigators, insecticides, 

 and so on, they must all be counted as make- 

 shifts at the best they alleviate but do not 

 prevent. 



I quite well remember conversations with 

 one of the best known of the older practical 

 entomologists of the country, Dr. Otto Lug- 

 ger, since deceased, who had for many years 

 been making a deep study of the subject of 

 insect control. In fact, many years before any 

 public announcement of the prevention of 

 fevers in tropic countries by the exclusion of 

 mosquitos, he had demonstrated the truth un- 

 derlying while engaged in natural history 

 researches in Central America. He had been 



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