THE BROWN-TAIL MOTH IN NEW HAMPSHIRE. 



219 



August and the young caterpillars skeletonize the leaves 

 prior to forming their winter webs (see figures 4 and 5), 

 they may be readilly killed by spraying with arsenate of 

 lead or Paris Green. In the apple orchard there are num- 

 erous other caterpillars doing more or less damage to the 

 foliage at this season which may be controlled by the same 

 spraying, which therefore becomes a practice to be com- 

 mended. Experiments made by us during the past season 

 show that not less than five pounds of arsenate of lead to a 

 barrel of water should be used, and that an increase to ten 

 pounds per barrel merely results in killing the caterpillars 

 a day or two quicker. Arsenate of lead is preferred on ac- 

 count of its unusual adhesive properties, remaining on the 

 foliage several weeks after hard rains. Paris Green is very 

 much quicker in its effect and is, therefore, to be preferred 

 in some respects when there is no immediate prospect of 

 rain. Care must be taken in the use of Paris Green that 

 plenty of lime be added to prevent burning of the foliage, 

 while arsenate of lead may be used in large quantities with- 

 out danger in this regard. Our experiments indicate that 



Fig. 4.— Newly hatched brown-tail moth caterpillars feeding on upper surface 



of apple leaf— enlarged. 



