15 
remedy one day may be wrong the next day, just as we are able to 
unravel nature’s secrets and interpret them for our own good. 
Since the above was read the writer has tested a lot of twigs from 
the Charles County orchard and has bred numerous specimens of A 
Suscipennis, thus proving that a parasite is thoroughiy established 
there. 
THE BROWN-TAIL MOTH IN MASSACHUSETTS. 
By A. H. Kirxxianp, Malden, Mass. 
It is seldom possible to record with accuracy from year to year the 
spread of an introduced insect pest. The average working entomolo- 
gist has at his disposal neither the time nor the funds necessary to 
follow the spreading swarms afield. It therefore follows that in such 
cases our records of insect dissemination have been built up by col- 
lecting and combining data in the possession of entomologists and lay- 
men. This method is the only practicable one in the case of those 
insects whose spread is dependent upon the agency of commerce. 
Such cases do not possess the interest, at least from a biological stand- 
point, of those where natural means of distribution predominate. 
The writer thinks the present a good time to record a few notes on 
the natural spread of the imported brown-tail moth in Massachusetts, 
particularly since the abandonment of work against this insect will 
prevent the accurate collection of further data. 
With this insect in Massachusetts a unique condition has made it 
possible to follow its increasing distribution with more than ordinary 
accuracy. When the insect was first noticed in the State, in 1897, the 
work of combating it was placed in charge of the board of agriculture. 
At that time the board had employed in the gypsy-moth work about 
300 men, who from practical experience were fairly close observers 
of insect life. While it should not be understood that these men 
were experts, yet they were capable of recognizing the gypsy moth 
in all stages, and soon gained an equally accurate knowledge of the 
brown-tail moth, particularly after having experienced the intense 
nettling caused by the caterpillars. The duties of selected mem- 
bers of this working force included a search each fall to determine 
the extent of the spread of the brown-tail moth outside the area occu- 
pied the previous spring. With such employees the chance for erro- 
neous determinations of the moth was small. The writer might add 
that he was able to verify the determinations in all doubtful cases. 
In the paper read by Prof. C. H. Fernald before this body in 1898 
a description was given of the high gale which, occurring in the flying 
season of 1897, disseminated the moth for many miles to the north- 
ward. ‘This northerly spread is even more apparent at the present 
