292 BOARD OF AGRICULTURE. [Pub. Doc. 



Though every effort was made in 1891 to exterminate the 

 moth from the region most infested, the search of 1892 gave 

 abundant evidence of the impossibility of exterminating it in 

 one year's time. Although the greater part of the eggs had 

 been destroyed, caterpillars were found in most parts of the 

 infested territory. It was seen that eggs scattered on the 

 ground and exposed to the elements during winter produced 

 some caterpillars. The eggs are thus frequently scattered by 

 the wind ; by ice forming on the trees ; by people picking fruit 

 or trimming and cutting down trees ; and by various other 

 causes. The female moth often drops a few eggs upon the 

 ground or in the crevices of the bark where they are likely 

 to escape the most thorough search. Such eggs are often 

 fertile. Young caterpillars have been seen to come forth 

 from them in the spring. Though many colonies neverthe- 

 less have been exterminated by destroying the eggs, it will 

 be seen how difBcu-lt, nay, even impossible, is complete 

 extermination over a large area by this method alone. 



It is now a well-known fact that spraying with the 

 arsenical insecticides commonly used is only partially effec- 

 tive with this insect, and such was the prejudice prevailing 

 against this method in some of the infested towns that people 

 frequently washed the trees and shrubbery with water from 

 the garden hose and so neutralized the effect of the spraying. 



Bands of insect lime merely prevent the caterpillars from 

 climbing trees which have been first cleared of eggs. But 

 they frequently find means to ascend the trees in spite of the 

 lime bands, and if driven from the trees they will betake 

 themselves to the gardens and shrubbery. 



While the burlap bands aftbrd a means of assembling the 

 caterpillars so that they may be easily killed, they cannot 

 all be disposed of in this way, as there seems to be an 

 increasing tendency to avoid the " burlaps," possibly due to 

 natural selection. 



What Means of Extermination then remain f 



There are certainly two, and possibly three, means which 



have accomplished the object sought wherever they have 



]>een thoroughly applied. Fire can be used either to destroy 



the eggs of the moth, to kill the caterpillars or to starve 



