158 THE GYPSY MOTH. 



much of the poison will be washed off or gather in spots. 

 If the trees are sprayed in dry weather or at a time in the 

 day when the leaves are dry, the poison adheres to the leaves 

 as it falls and is thus most effective. 



How to Spray for the Gypsy Moth. 



In many cases spraying for insect pests is a failure. Where 

 tender plants and choice fruit trees are sprayed, more harm 

 than good is often done. This is not to be attributed, how- 

 ever, to the method, but to either poor machinery or to 

 ignorance or carelessness in the use of insecticides. When 

 spraying is thoroughly and carefully done according to the 

 rules given by the best authorities, it will almost always give 

 good results with most leaf-eating insects. Yet, as has been 

 shown, the most careful spraying with the best insecticides 

 may fail to check the gypsy moth. If spraying is done 

 when the caterpillars are young and feeding mostly on the 

 lower surface of the leaves, it will be most effective. Use 

 not less than fifteen pounds of arsenate of lead and two 

 quarts of glucose to one hundred and fifty gallons of water. 

 Be sure that the acetate of lead is dissolved in water (warm 

 if need be) before it enters the tank. Stir the mixture con- 

 stantly and spray evenly and thoroughly with a fine spray. 

 If this does not kill, double the dose. 



Spray fruit trees to as high a point as possible from 

 the ground by the use of a long pole or extension with any 

 nozzle which will throw a very fine spray, spraying always 

 in such a way as to reach the under side of the leaves. 



On tall shade or forest trees spraying may be best accom- 

 plished by the use of a ladder. A nozzle which will throw 

 a coarse spray to a distance, like the Gem, Lowell, Nixon 

 or McGowen, may be used. Often the lower limbs may be 

 sprayed from the ground by means of a pole. The pole can- 

 not be so well handled in the tree, and the workman can 

 spray best by climbing up the main trunks and branches 

 and spraying from below as he climbs. If the spraying is 

 done later in the season, particular attention must be paid 

 to the ends of the branches and to the tops of the trees, for 

 many of the larger caterpillars crawl to the very tips of the 

 branches and to the tops of the trees to feed. 



