REMEDIES AGAINST SCALE-INSECTS. 



101 



Fio. 44. Cyclone or eddy-chamber 

 nozzle. (After Barnard.) 



rotation In the chamber. Its whirling motion disperses it broadly from 

 the orifice, and produces a very fine spray, which may be converted 

 into a cloud of mist by increasing the pressure 

 in the pump. The perforated face of the noz- 

 zle-chamber is removable for convenience in 

 clearing the orifice when it clogs. The diam- 

 eter of the chamber inside need not exceed 

 one-half inch and its depth one-quarter inch. 

 A nozzle of these dimensions attached to the 

 aquapult pump covers one and a half square 

 yards of surface at a distance of 4 or 5 feet 

 from the orifice. The amount of dispersion 

 depends somewhat upon the thickness of the 

 perforated face of the chamber. The diam 

 eter of the cone of spray may be increased by 

 countersinking the exit hole and making its 

 edges thin. 



Three-eighths-inch guin tubing is sufficient- 

 ly large to supply one or a gang of several 

 nozzles. The tubing must be strengthened 

 with one ply of cloth. 



In use, the end of the hose is supported by being fastened to a light 

 rod of wood, which forms a handle, by means of which the nozzle may 

 be applied to all parts of the tree. For full- sized trees a rod long 

 enough to reach nearly to their tops must be used. For this purpose a 

 convenient device may be made by passing the small rubber hose 

 through a hollow bamboo rod of the required length. A three-six- 

 teenth brass tube inserted in a bamboo rod has also been used. 



Plate VII exhibits a complete outfit for treating orange groves with 

 liquid insecticides, from a photograph taken during actual service in the 

 field. This consists of a common pendulum pump inserted in a barrel 

 and mounted upon a cart. The liquid is delivered through two lines of 

 hose, each ending in a cyclone nozzle. The arrangement here shown 

 permits the spraying of two rows of young trees at once, and thus effects 

 a considerable saving in time. In the same plate is shown an aquapult 

 pump fitted with a cyclone nozzle and a single length (12 feet) of three- 

 eighths-inch hose. The pump is inserted in a pail, ready for use as a 

 portable apparatus for one, or preferably for two men. 



Several Applications necessary. Unless exceptional care is exercised 

 some portions of the bark or leaves will escape thorough wetting and 

 isolated scales will be left alive. The eggs also to some extent will 

 escape destruction and may hatch in sufficient numbers to restock the 

 plant. As a rule, therefore, two, or even more, applications will be nec- 

 essary. A second application should not follow too closely on the first. 

 Sufficient time should be given for the hatching of all the eggs which 

 may have been left alive. On the other hand, if delayed too long, a 



