14 
METHODS USED BY THE STATE AUTHORITIES. 
After the preliminary inspection work mentioned in the previous sec- 
tion had been largely accomplished, methods of actual destruction of 
the insect were adopted. In the course of the eight years during which 
this work has been carried on, there has been a steady improvement in 
the efficacy of the insecticide measures used. For a time these methods 
consisted almost entirely of the destruction of the egg masses, spraying 
with arsenical poisons for the caterpillars and killing the caterpillars 
under burlap bands on tree trunks, and these measures are to-day prac- 
tically the only ones used where colonies exist in towns or on cultivated 
grounds. During the past two years, however, work has been carried 
on with great energy in forest lands, and here the means mentioned 
have been supplemented with extensive clearing out of underbrush, 
thinning out of the woods by the felling of a certain proportion of the 
timber, and by burning over the ground. When the writer first visited 
the infested region in the summer of 1894 the earlier methods only 
were in use. Nevertheless a number of original methods had been 
adopted, and he was impressed, as everyone has been who has thor- 
oughly investigated the work of the State officials, with the systematic 
and thorough manner in which the remedial work was being carried on. 
He had nothing but praise for this work, and the only obstacle to the 
entire success of the effort which he foresaw was the occurrence of the 
insect in islands throughout large stretches of densely wooded country, 
where the methods then in use could hardly be completely effective. 
He did not anticipate the possibility of such radical woodland meas- 
ures as have been instituted. But of this more will be said in a later 
paragraph. 
The conspicuous color of the egg clusters and the long duration of 
the insect in this stage of existence, together with the fact that the 
destruction of an egg mass prevents much potential damage, very early 
suggested to the officials the feasibility and importance of fighting the 
insect in this stage. Indeed, one of the first measures adopted by the 
selectmen of Medford was the collection of egg clusters from the trunks 
of shade trees in the infested district. Moreover, it seems that this is 
the principal remedial measure adopted in Europe. 
The great success, however, which had attended spraying operations 
against other leaf-feeding caterpillars in the United States caused cer- 
tain economic entomologists to believe that the labor of collecting these 
egg clusters during the winter time was unnecessarily great, and that 
there would be much economy both in labor and money in waiting until 
the eggs hatched in the early summer and then spraying the surround- 
ing vegetation with paris green or london purple. In fact, this argu- 
ment was put forward very strongly by Professor Riley in his testimony 
before the State legislative committee on agriculture in Boston, March 
4, 1891. It soon developed, however, that the Gipsy Moth caterpillar 
was unusually immune to the effects of arsenicals; that trees sprayed 
