AN AGRICULTURAL REVOLUTION. 



6 39 



as large a profit from the agriculture of this great agricultural 

 State as do the farmers themselves." 



Fortunately, however, much progress has recently been made 

 in a knowledge of efficient means of preventing this vast drain 

 upon our productive system. By the introduction of a simple 

 mechanical contrivance for the application of insecticides and 

 fungicides, the methods of combating these foes have been revo- 

 lutionized ; and in many localities where the production of special 

 crops had been abandoned new life has been put into their de- 

 velopment. This contrivance is commonly called the spraying 

 machine. It consists essentially of a force pump and spray noz- 

 zle connected with a reservoir, by means of which certain sub- 

 stances that have a destructive effect upon insect and fungous 

 life may be rapidly and evenly 

 distributed over the outer sur- 

 faces of trees, shrubs, vines, and 

 herbaceous plants. 



In America the spraying- 

 machine seems to have first 

 come into general use to pre- 

 vent the injuries of the codling 

 moth or apple worm. This is 

 a very destructive and widely 

 distributed insect, for which 

 there had before been known 

 no remedy that can compare 

 with spraying in cheapness and 

 efficiency. These worms hatch 

 from eggs laid in the calyx ends 

 of the newly formed apples by 

 a small, chocolate-colored moth 

 (represented at/ and g, Fig. 1). 

 These eggs are deposited in spring or early summer, from the time 

 the young apples are as large as peas until they attain the size of 

 small hickory nuts. The eggs are placed on the outside of the 

 fruit, and the resulting worms nibble at the skin, finally biting 

 through and eating toward the core. They continue feeding for 

 three or four weeks, when they become three fourths of an inch 

 long, whitish or pinkish-white in color, and of the general form 

 shown in Fig. 1, e. They are now full grown as larva3, and leave 

 the apples to spin, in some temporary shelter, slight silken cocoons 

 {%), in which they transform to pupas (d), to change a fortnight 

 later into fall-fledged moths. These moths deposit eggs about 

 midsummer for a second brood of worms. 



The earlier preventives of codling-moth injury included such 

 partially effective measures as banding the trees with wisps of 



Fig. 1. — Codling Moth : a, injured apple ; 

 b, place where egg is laid ; e, larva ; d, 

 pupa ; *, cocoon ; g, /, moth ; h, head of 

 larva. (After Kiley.) 



