248 THE BOOK OF CORN 



the most elaborate trials made by Professors Com- 

 stock and Slingerland. Late fall plowing, breaking 

 open the pupal chambers, will probably diminish the 

 number of these beetles during the following year. 

 Professor Forbes has suggested a systematic rota- 

 tion intended to interpose between grass and corn a 

 crop not vulnerable to the wireworms. Otherwise 

 we are substantially without a hint of any means 

 of diminishing the ravages of these insects other than 

 the time-honored resource of the corn farmer, namely, 

 late planting of his corn the second year after sod, 

 and late replanting if the first planting is destroyed. 

 In the latter case it is well to plant between the 

 rows, allowing the first corn to stand as long as is 

 consistent with a proper cultivation of the field. 

 All the wireworms being at the time concentrated 

 on the old hills, if these be destroyed, when the field 

 is planted the second time, the wireworms still active 

 in the earth are forced to attack the freshly planted 

 kernels as their only food resource. 



Even a clean fallow for an entire season will not 

 starve out the worms and neither buckwheat, mustard, 

 nor rape crops, frequently recommended to clear the 

 earth of wireworms, will accomplish the desired result. 

 Salt applied at the rate of sixteen hundred pounds per 

 acre, a heavy dressing, neither drives the wireworms 

 deeper into the soil nor causes them to migrate to any 

 appreciable distance. Kainit used as a fertilizer in 

 very large quantities has little effect if any on the 

 worms. The same may be said of muriate of potash, 

 lime and chloride of lime. Gas lime is capable of 

 destroying the worms but has to be applied in such 

 large quantities as to be impracticable on large areas. 

 The most promising method for relief is crop rotation, 

 in which clover follows grass and is itself followed by 

 corn. According to this plan pastures and meadows 



