PROGRESS OF EXTERMINATION. 45 



V 



reduced by cutting out only the worthless trees, and the 

 ground cleaned up by removing and burning the under- 

 brush. In certain colonies where the moth had appeared 

 in many thousands, the eggs on the trees were destroyed 

 and the ground burned over with oil. Later the trees were 

 banded with Raupenleiin, to prevent the caterpillars ascend- 

 ing, and the few caterpillars which hatched from the eggs 

 remaining on the ground were thus starved. Any one of 

 these methods will bring about extermination, if supple- 

 mented by such others as can be used to the best advantage. 

 Extermination here, as elsewhere, must be verified through 

 several years by a thorough search in the summer for the 

 caterpillars and in the winter for the eggs of the moth. 



THE PROGRESS OF EXTERMINATION. 



All practical entomologists who have followed the work of 

 extermination for the past six or seven years are now con- 

 vinced that the gypsy moth can be exterminated, and that its 

 extermination, under the present methods, is only a question 

 of time and adequate appropriations. People who hold op- 

 posite opinions seem to be impressed by the belief that the 

 gypsy moth is generally distributed over the whole so-called 

 infested territory of more than 200 square miles. This, em- 

 phatically, is not the case, nor has it ever been the case. 

 Outside the central towns the moth is found only in isolated 

 swarms or colonies, separated by wide intervals of uninfested 

 ground. In fact, the greater part of the region called in- 

 fested has never been invaded by the moth. For this reason 

 it is never necessary to make a careful, thorough search over 

 all the territory of the towns in the infested region, for the 

 purpose of discovering single caterpillars or moths. Such 

 scrupulous searching is essential only in and around the 

 known colonies. In seeking for and destroying the moth in 

 these colonies, the greater part of the appropriation has al- 

 ways been expended, and must always be, so long as the 

 moths are numerous. But there should also be, from time to 

 time, a rather rapid search of all the region between the col- 

 onies. This should be conducted in the fall, winter and 

 early spring, when deciduous trees bear little or no foli- 

 age, to provide against the establishment of new colonies. 



