60 The Spraying of Plants. 



to central Missouri and southern Illinois. In July, 1870, the 

 insect was found in Ontario, Canada; and in 1872 it arrived 

 in central New York. Two years later, it reached the Atlantic 

 coast, having crossed nearly two-thirds of the continent in the 

 short space of fifteen years. 



The insects ate as vigorously as they traveled. Potato 

 fields were stripped of every vestige of foliage; desolation 

 could everywhere be seen ; and as this increased, the yield of 

 tubers decreased. At first, it seemed as if nothing could stop 

 the ravages of the pest, and it threatened the entire potato 

 industry of the country. All known remedies failed, and the 

 future must have appeared dark to the Western planters, until 

 some remedy could be found that would destroy the beetles, 

 and save the foliage of the vines. 



Fortunately, this remedy was not long in coming ; but who 

 first suggested it, and who first used it for the destruction of 

 the potato beetle, will perhaps never be told. Paris green 

 appeared upon the scene sometime between 1860 and 1870. 

 The use of this deadly poison may have originated with sev- 

 eral persons; for some poison of this nature was evidently 

 needed to destroy such a voracious feeder. The use of Paris 

 green as a standard insecticide undoubtedly began in the 

 Western States, and there the applications to the vines were 

 considered as of primary importance in securing a crop. The 

 use of the poison was, to a limited extent, checked by the 

 possible dangers connected with its careless handling. It is 

 also very injurious to foliage, when applied pure, especially in 

 large quantities, and this may have exerted a certain influence 

 in preventing its general adoption. But the weight of these 

 objections was soon overcome by the absolute necessity of 

 treating the vines in order to save them. 



In 1868 the value of the poison appears to have been fairly 

 well known, 1 one man going so far as to obtain a patent upon 

 a mixture of one part Paris green and two of mineral paint. 2 



1 American Entomologist, 1869, July, 219, citing from the Galena (Ills.) 

 Gazette. The editors of the Am. Ent. also carried on experiments in 1868. See, 

 also, an account of the experiments made by Saunders and Eeed, in which were 

 tested Paris green, arsenious acid, copper sulphate, bichromate of potash, powdered 

 hellebore, carbonate of lime, and ashes mixed with air-slaked lime ; none of these, 

 except Paris green, were found to be of value. Canadian EntomologiHt, 1871, 

 July, 41. 2 Kiley, U. S. Ent. Com. 1880, Bull. 3, 57. 



