192 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 12 



are subterranean in their habits, and when placed on the surface of the 

 ground they immediately burrow into the dirt. 



Control 



Thus far it has not been possible to carry out any extensive experi- 

 ments on the control of Eleodes opaca in the field. The measures advo- 

 cated are based on a study of the history of over 200 infested fields 

 obtained through personal visits, and from questionnaires furnished to 

 the farmers. In most cases the history of the field has been obtained 

 for the preceding two or three years. A study of the data thus secured 

 suggests several promising methods of procedure which have proved 

 beneficial in controlling or reducing the amount of injury. 



Rotation. — The investigations in many fields infested by false wire- 

 worms show that in nearly all cases the greatest injury has occurred on 

 land continuously cropped to wheat, while fields that have been in a 

 row crop or fallowed previous to wheat have suffered little damage. 

 The beetles are wingless, and migration from field to field must take 

 place on foot. These facts indicate that a careful rotation of crops, 

 combined with certain other practices to be mentioned later, would 

 eliminate much of the damage and the writer has seen many fields 

 where this has been the case. In following a system of rotation in 

 western Kansas, it must be remembered that the number of crops that 

 can be alternated with wheat is limited principally to feed crops such as 

 sweet sorghums, kafir, milo, and feterita, and, under certain conditions, 

 corn. Occasionally oats and barley are included, and many farmers 

 practice a rotation whereby a small grain crop is planted early in the 

 spring on land where the worms have destroj'^ed the wheat crop the 

 previous fall. Such a system usually increases the injury since it pro- 

 vides additional food at a time when the larvae are maturing. Where 

 the fall wheat has been destroyed, the land should be worked 

 about the first of May and planted to a row crop. If the field is kept 

 cultivated and free from weeds and grasses, it is often possible to return 

 the land to wheat in the fall. This is not always feasible,. since the 

 feed crops are late maturing, and in this case oats or barley should be 

 planted in the spring to be followed by wheat in the fall. Call and 

 Salmon (1918, pp. 42-43) suggest the following rotation for western 

 Kansas: wheat two years; kafir or other sorghums, one year; and sum- 

 mer fallow, one year. By this system, one-half of the farm is in wheat 

 each year, one-fourth in a feed crop, and one-fourth is fallowed for the 

 next wheat crop. Such a system, if carefully followed, would reduce 

 the false wire worm injury and at the same time increase the yield. 



Summer Fallow. — The practice of summer fallow whereby the land 

 lies idle for a year, being worked sufficiently to keep down the plant 



