127 



The following table shows the proportions of Paris green and water 

 used, and the time required to kill all the caterpillars in each molt. 



Tarle. 



Proportion of Paris Green First Molt. Second Molt. Third Molt. Fourth Molt, 



to Water. Days. Days. Days. Days. 



1 pound to 100 gallons, 2 2 11 



" 150 '' 2 1 1 1 



" 200 " 11 3 3 



250 " 3 3 3 3 



" 300 " 2 2 2 2 



" 400 '^2 3 6 2 



500 " 7 6 7 



" 600 " 7 3 10 



" 700 " 4 5 11 



" 800 " 6 7 9 



" 900 " 7 9 6 



" 1000 " 8 19 12 



Conclusions. 



A careful consideration of these experiments leads us to the con- 

 clusions : 1st, That the smallest proportions, as 1 lb. to 800 or 

 1000 gallons, require so long a time to kill the caterpillars that they 

 might wander off, or that showers might wash the Paris green from 

 the trees before they would eat enough to kill them. 2d, That the 

 large or nearly grown caterpillars are quite as readily killed by any 

 of the proportions used in these experiments as those just hatched, 

 or in early molts. 3rd, The proportions of one pound of Paris green 

 to 100 gallons of water, or one pound to 150 gallons sprayed upon 

 apple trees, in experiments that have been" conducted here for three 

 years past, have burned the foliage to such an extent as to injure 

 the trees very materially ; and these experiments lead us to conclude 

 that the most suitable proportions to be used on apple trees in this 

 region, and perhaps throughout the state, are one pound of Paris 

 green to 200, 250 or 300 gallons of water. 



