150 THE GYPSY MOTH. 



orchards. The Gould handy knapsack spraying pump 

 (Plate XXIV., Fig. 1) has been used experimentally in 

 the gypsy-moth work and gives fairly good results. These 

 knapsack sprayers, however, are inconvenient when spraying 

 is required on a large scale as they do not carry sufficient 

 liquid. 



The hand tank and pump used with the cyclone burner 

 (page 120, Fig. 1) has been found very useful in spraying 

 small orchards. With the pole attachment most of the trees 

 can be sprayed from the ground. This tank may be carried 

 and operated by two men. 



Gould's barrel sprayer is shown in Plate XXV., Fig. 2. 

 It has been very useful in our experimental work, and could 

 no doubt be used to advantage in spraying small orchards, 

 gardens and field crops. It has the advantage of being 

 movable without the aid of a horse. Its wide tires can be 

 run over ground where it would not be possible for a horse 

 to go without doing injury. 



In spraying in gardens where tender and valuable plants 

 are grown or in orchards containing choice varieties of fruit 

 trees, it is most essential that the liquid be thoroughly 

 stirred, and especially that the spray be distributed evenly 

 and in a fine mist, otherwise injury to the plant may result. 

 Spraying may be done with the crudest implements. Corn- 

 brooms and whitewash brushes have been used with good 

 effect in some cases, but for uniformly good results we have 

 seen nothing better than some of the modifications of the 

 cyclone nozzle (Plate XXVII., Fig. 2). This nozzle was 

 originally brought to public notice by Professor Riley, then 

 chief of the United States Entomological Commission. When 

 used in its original form, it throws a finer and more even 

 spray than any nozzle which has come to our notice, yet it 

 has faults which preclude its use except in very limited 

 fields. It sprays very slowly and is frequently clogged by 

 the coarser particles of the insecticide or by foreign sub- 

 stances, the perforation through which the liquid passes out 

 in spray being very small. It is then necessary to remove 

 the cap and clear the nozzle: Therefore much time is con- 

 sumed in its use. When first tried experimentally at 

 Medford it was found that an hour was required to spray 



