INSECTS INJURIOUS TO CORN. 25I 



When such infested fields are plowed and planted to some crop such 

 as corn, wheat or other grains, or, in fact, most any farm or garden crop, 

 these wireworms are deprived of their great abundance of food, and then 

 show their presence by the great injury which they do by feeding upon 

 the roots of the comparatively small amount of plants that have been 

 introduced there by the agriculturist. 



Wireworms do not confine their attacks to the roots of corn and 

 other cultivated plants, but will attack the corn or seed when put in the 

 ground and before it has had time to germinate, and will eat holes through 

 it, hollowing it out inside or devouring it entirely. Those seeds that 

 have succeeded in germinating are also attacked and the young develop- 

 ing roots eaten, or the plants that have succeeded in reaching several 

 inches in height will have their roots eaten or holes eaten through them, 

 and even the base of the stem eaten into and the plant killed. The 

 farmer, however, usually complains most severely of the attack upon the 

 seed of the corn before it has had time to germinate. It appears that 

 those corn fields (this also applies to wheat fields) which are in low 

 ground, or those portions of larger fields that are in low or hollow places, 

 are more liable to injury from wireworms than are the higher and better 

 drained fields or portions of fields. In some instances it also appears that 

 corn planted the second year after the plowing of the meadow or pasture 

 seems to sufifer more from injury from the attack of wireworms than it 

 did the first year from plowing. In such instances it appears that the 

 young wireworms had sufficient food remaining in the form of the roots 

 of the original grass to sustain their life for the first season, and that 

 by the next spring the roots had decayed and disappeared sufficiently 

 to deprive them of food and forced them to then attack the cultivated 

 plants. It is also frequently the case that the wireworms do the greatest 

 amount of damage during the spring, apparently their long winter fast 

 having sharpened their appetites, which become somewhat satisfied later 

 in the season. 



It is almost impossible to poison the wireworm, either in the adult 

 or larval stage. Certainly the poisons in our ordinary insecticides are 

 not strong enough to kill them. The application of various chemicals to 

 the soil will not injure them unless used in such unreasonable quantities as 

 to utterly unwarrant any such procedure. The only successful method of 

 killing the wireworms that I know of is to take advantage of the weak 

 point in their life history, which I have before described, viz., the ex- 

 tremely delicate condition or the pupae and newly developed adults. It 

 has been found by Professor Comstock that these insects are so readily 

 killed, when in the stages mentioned that, by plowing the field to a depth 



