488 IOWA DEPARTMENT OF AGRICULTURE 



FALL PLOWING. 



Fall plowing is of importance in the control of the grub, during the year 

 when it changes to the adult form (1919 and 1922). If done early, while 

 the pupa is soft and helpless, merely breaking the cell means the death 

 of the insect. If the plowing is done later, the beetle is soft and tender and 

 cannot readily construct a new cell in which to pass the winter and so will 

 perish. 



WHAT TO DO IN 1919 AND 1922. 



Figure 2 shows that the large grubs will come up to the surface in the 

 spring of 1919 and in 1922 and feed greedily a short time only, then they 

 stop feeding suddenly and form an earthen cell, in which they later change 

 to a beetle. 



Early corn will suffer, but can be replanted. Later corn may be slight- 

 ly injured at first, but will recover and make a good crop. All sod land 

 intended for cultivation during the next two years should be broken in 

 the fall of 1919 or the spring of 1920 before the "June bugs" fly and lay 

 eggs. If this is done, the land will be free from grubs. 



WHAT TO DO IN 1920 AND 1923. 



These will be "June bug years," as shown in figure 2. Trees may be de- 

 foliated by the beetles, but there will be no injury to the crops. Do not 

 plant small grain on land intended for corn the next year. Alfalfa or 

 clover may be broken up in the fall for corn land. 



WHAT TO DO IN 1921 AND 1924. 



These are the "grub years." Corn should not be planted on land that 

 was in grass or grain the previous year if small grubs were present in the 

 early fall. A corn field that is being injured should not be replanted to 

 corn, but may be planted to buckwheat, beans or peas. Millet or cane may 

 be used if the grubs are not too abundant. 



