148 NEW YORK STATE MUSEUM 



been marked by a repetition of the injury, though the attack 

 was not so severe as that of the preceding summer. The causes 

 for this latter condition may be in part due to repressive meas- 

 ures adopted by citizens of that city, but on the whole we are 

 inclined to believe that natural enemies or unfavorable climatic 

 conditions were the most potent factors in reducing the numbers 

 of this pest. The condition of the trees in that city is a most 

 effective argument in favor of establishing a paid forester or 

 other official whose duty it shall be to look after the street trees 

 as well as those in the parks and see that they are adequately 

 protected from insect ravages. This matter is one of increasing 

 importance, as our cities are growing rapidly in size, and as a 

 consequence there is a greater massing of foliage and therefore 

 more favorable conditions for the development of large numbers 

 of a species. It requires but a few years for insects to destroy 

 a. tree which may have been from 10 to 50 or more years in 

 growing, and in cities where this is allowed a deterioration of 

 real estate values must follow, accompanied by an increase of 

 various diseases and a higher mortality, because of the rapid and 

 extreme temperature changes due to the absence of trees. 



This pest can be easily controlled in either one of two ways. 

 Many of the caterpillars can be jarred or brushed from the in- 

 fested trees, and their ascent prevented by the use of a band of 

 loose cotton tied around the tree or a band of tar on a piece of 

 stout paper, the latter to prevent injury to the tree. Both of 

 these materials are very effective, and in our judgment vastly 

 superior to the brass bands seen on the trunks of so many shade 

 trees in Buffalo. Bands, however, are of value only in keeping 

 the caterpillars off the trees. The jarring of the pests is some- 

 what laborious, and as the insects are readily detroyed by spray- 

 ing with an arsenical poison a prompt application of some such 

 material to the foliage is advisable. Arsenate of lead is one 

 of the best poisons. It may be applied at the rate of 4 pounds 

 to 50 gallons of water. Use this insecticide only in the pre- 

 pared paste form, diluting to the proper extent, and under no 

 conditions purchase the crystalline article. The older standard 



