142 



THE POTATO. 



Wireworm. Wireworms are of two kinds, true and 

 false, and the former are, perhaps, the most destructive 

 of all pests that attack the potato. They exist in the 

 grub state from three to five years, and during that time 

 feed voraciously on the roots of farm crops, including the 

 potato, not resting content with one, but passing from 

 root to root, gnawing here and there, and inflicting very 

 severe damage. True wireworms have six legs, whereas 

 the false wireworms (millepedes) have many more. The 

 Click Beetle, of which the wireworm is the grub, is well 

 known, children often finding them dur.ng the summer in 



CLICK BEEIJ.E AND WIEEWORM. 



a Wireworm ; I tail joint; c parent of wireworm ; <? antennae of beetle; 

 e natural size of cliek beetle. 



grass fields, laying them on their backs, and watching 

 them regain their position by giving a spring in the air. 

 The noise which accompanies this movement is the origin 

 of the name " Click." There are three species, the larvae 

 of which are harmful to the potato, namely, Agriotes 

 lineatus, obscurus, and sputator. The grubs are hatched 

 from eggs laid in the soil near the roots of plants, or occa- 

 sionally in the lower leaves, where they envelop the stem. 

 They start feeding at once, devouring the underground 

 stems, continuing for a period of at least three years, going 

 deeper into the soil during the winter months. At the end 

 of their grub existence they descend into the earth, and 

 change into beetles, which emerge in about three weeks. 



