14 



nozzle of the Vermorel type to secure this effect. An elbow designed 

 for this purpose is shown in figure 5. 



Kerosene-soap emulsion, the standard remedy for aphides, is the best 

 insecticide for spraying purposes, but various soap solutions are used 

 both for the melon and pea aphides. The}^ are diluted with 6 to 8 parts 

 of water. The emulsion and soap washes are of particular value when 

 the plants are small, as then the aphides can be more readily reached 

 than when the leaves have grown to larger size; and, to repeat, if inju- 

 ries are to be averted the insect should be checked on its first appear- 

 ance, not alone on cucumbers, melons, squashes, or whatever the main 

 crop may be, but upon all neighboring plants which may harboi the 

 insect, including beds of strawberry or groves of orange trees. 



Kerosene- soap emulsion is prepared by combining 2 gallons of kero- 

 sene, one-half pound of whale-oil soap, or 1 quart of soft soap, with 1 

 gallon of water. The soap is dissolved in boiling water and then 

 poured while still boiling hot (away from the fire) into the kerosene. 

 The mixture is then churned rapidly for about five minutes, pumping 

 the liquid back upon itself by means of a force pump and direct-dis- 

 charge nozzle throwing a strong stream. At the 

 end of this time the mixture will have become of 

 the consistency of thick cream. Properly prepared, 

 an emulsion will keep almost indefinitel}", and 

 should be diluted onh^ as needed for use. For 

 most species of aphides the staple emulsion should 

 -, ^ ^^^ ,, , be diluted with from 10 to 20 parts of water. In 



Fig. 5.— Elbow attach- -i 



ment for underspray- the preparation of kcroscnc femulsion a force pump 

 mg. Reduced. ^^ ^ necessit}^ siucc if not made according to 



directions a perfect emulsion is not formed. There is then danger of 

 injury to the plants bv the kerosene, as also useless waste. There is 

 danger and waste, too, if the insecticide is not applied by means of a 

 fine nozzle in the form of a spray^ which should be fin-e and mist-like, 

 or "like a fog," as some one has aptly exprest it. It should be 

 spra3^ed onl}" for a long enough time to cover the plants, otherwise 

 the liquid forms into globules and runs ofi'. Figure 6 illustrates 

 the method of operating a knapsack spraj^er so as to produce an 

 underspraying. 



Spraying vnth u:ater. — Where a few plants only are to be protected, 

 and it is possible to direct a strong stream of water upon them from a 

 garden hose, syringe, or spraying machine, so as to wash ofi* the 

 insects, the aphis can be materially checked without the use of other 

 materials. Such of the insects as come into direct contact with a stift' 

 spra}^ are unable to survive, while others that are dislodged from the 

 plants do not succeed in returning. Many are wingless during the 

 greater part of the season and unable to crawl any distance, particu- 

 larly if the ground be dry and hot. 



