114 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



calyx cup, and would thus mostly escape destruction unless the poison 

 had been there placed. Other investigators have shown, notably the 

 late Professor Slingerland, that codling-moth larva? in the East feed 

 in the outer calyx cup, and the results which have been obtained with 

 mist sprays in the East during the past twenty-five years, filling 

 mostly only the outer calyx cavity, have been much more favorable 

 than could be expected were it the rule that feeding occurs principally 

 in the inner cup. The stamen bars, as shown in the figure, form a 

 dome or shield over the cavity below, and the poison is best forced 



Fig. 33.— The condition of the calyx cup of the apple in relation to spraying for the codling moth: Fig. L— 

 A calyx cup, five days after the petals fell, split open to show two cavities; la, the roof of stamens as seen 

 from above. Fig. g.—A calyx cup two weeks after blossoming, showing the calyx lobes above; 2a, the 

 stamens from above to show spaces. Fig. 3.— The relation of the two cavities in a nearly grown apple; 

 Sa, stamens from above. (From Ball.) 



through these bars by a coarse, forceful spray, as from a Bordeaux 

 nozzle and with a pump pressure of from 175 to 200 or more pounds. 

 It is also required that the work of spraying be done very thoroughly, 

 the spray being directed from above into each and every fruit cluster. 

 The use of an elbow or crook between the rod and nozzle to incline 

 the nozzle at an angle of from 30 to 45 degrees with the spray rod 

 permits of better directing the spray downward, and even in the case 

 of small trees it is recommended to spray from a platform on the 

 wagon. The employment of a coarse nozzle and a high pressure uses 

 a large amount of spray before the trees are properly sprayed, literally 

 drenching the trees. 



