REPORT OF THE STATE ENTOMOLOGIST 1907 17 
measures are inapplicable to an extended forest area because 
of the enormous expense involved. The exceptional nature of 
the outbreak justifies the expectation that it will not continue 
more than two or three years, and such seems to have been the 
history in earlier attacks. Practically the only thing that can be 
done is to take advantage of the situation to emphasize the 
importance of protecting our native birds, and if possibie to 
create a Sentiment which will result in a substantial change in 
the present popular attitude toward these feathered allies. 
The depredations of leaf feeding insects are becoming more 
severe with advancing years, one of the most striking instances 
being the widespread injuries inflicted by certain species upon 
shade trees in our larger cities. The English sparrow, for ex- 
ample, has driven most of our native birds from the confines of 
our larger cities and, as a consequence, we have periodic out- 
breaks by the white marked tussock moth, Hemerocampa 
leucostigma Abb. & Sm., a species which has in recent 
years defoliated thousands of trees in New York cities and vil- 
lages. This insect, prior to the advent of the English sparrow, 
was regarded as an innocuous or harmless form, and such is its 
normal status in the country where native birds, particularly 
those which feed upon hairy caterpillars, are relatively abundant. 
The recent extended outbreak of the forest tent caterpillar, 
Malacosoma disstria Hubn. is another illustration, and 
the injuries inflicted by this species are probably chargeable, in 
.a large measure, to the great destruction of bird life in recent 
years. Dr William T. Hornaday of the New York Zoological 
Society, recently estimated that there has been a decrease of 
about 48% in the number of our birds during the past 15 years. 
These figures, taken in connection with the enormous number 
of insects devoured by birds, are very significant. 
_ Protection and encouragement of birds. The most important 
step in bird protection, according to E. H. Forbush, Ornitholo- 
gist of the Massachusetts State Board of Agriculture, is to 
protect birds about the home and endeavor to increase their 
numbers. Mr Forbush states that while it may be difficult for 
the individual to secure a permanent increase of migratory in- 
sectivorous birds on his farm, he can augment the number and 
size of the broods reared on his place, and thus increase the 
summer bird population. It is also possible to double the usual 
number of winter visitants. He cites the interesting case of 
