Wireworms 



black. This wilting of the leaves, associated with the darkening of the 

 tip where it is gnawed off, are characteristic of wireworm injury; how- 

 ever, the work of white grubs is very similar in the early part of the season. 



Many times beets eaten off by wireworms will throw out new roots, 

 especially if the soil is moist. Such beets develop a short sprangly root 

 as a rule. If the soil is dry and the weather warm the injured plants 

 usually die. This results in a poor stand if the injury is severe. 



Wireworm injury to sugar beets is not so severe in the Great Plains 

 States as it is farther east and in California. In the latter state the 

 damage is especially severe and is due to the sugar beet wireworm, which 

 is very numerous in the beet fields of some parts of that state. 



This wireworm also damages alfalfa, corn and beans. 



METHODS OF CONTROL 



Because of the great similarity between the habits and life history of 

 white grubs and wireworms, many of the same methods of control may 

 be used against both. 



Rotation 



As already stated, wireworms are most likely to be found in abund- 

 ance in pasture and meadow lands. When such lands are broken up 

 and planted to field crops those least apt to be badly injured should be 

 put in the first season. Row crops, such as sugar beets, corn or 

 potatoes, suffer most severely on infested ground. While the 

 small grains are sometimes severely injured they are not as a rule so 

 badly damaged as corn and root crops. 



Short rotations in which the land is not allowed to remain in grass 

 for any length of time will prevent the increase of wireworms, as the 

 females prefer grass lands as places to deposit their eggs. 



Plowing 



Early fall and late summer plowing will kill many newly transformed 

 beetles and pupae, especially if the surface is thoroughly worked with the 

 disc or harrow. 



Seed Treatment 



Sometimes wireworms injure seed corn before it germinates, thus 

 causing an almost total loss of stand in severe cases. Treating the corn 

 before planting by coating it with gas tar and dusting with Paris green 

 will almost entirely prevent loss, according to tests conducted by Dr. H. 

 T. Fernald in Massachusetts in 1908 and 1909. 



Poisoned Bait 



Many poisoned baits have been tried, but with very little success. 



DESCRIPTION 

 The Worm 



Wireworms vary in form and color as well as size. The species most 

 injurious to sugar beets resemble Figure 13, Plate I, Page 11. This is 

 the larva of the "click-beetle" (Fig. 16, Plate I). Figure 14, Plate I, is 

 an outline drawing of the last segment of the body of this worm. The 

 notch in the center is characteristic of many of our injurious wireworms. 

 Figure 18, Plate I represents another species often found in our fields. 



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