INSECTS AFFECTING GRAINS, GRASSES, ETC. 



81 



usually reveals that they belong to several species which are dis- 

 tinguished by a comparison of the caudal segments, as shown in 

 Fig. 59. 



Life History. The 

 life history is very simi- 

 lar to that of the white 

 grubs, except that from 

 three to five years are 

 required for the com- 

 plete life cycle. The 

 eggs are deposited in old 

 sod land, which is the 

 favorite breeding 

 ground. The detailed life his- 

 tories have not been carefully 

 studied, but the second year after 

 grass land has been planted in 

 grain is that in which the worst 

 injury occurs, particularly with 

 corn, upon which the attack is 

 more concentrated than with small 

 grains. The larvae become full 

 grown in midsummer, form small 

 cells in the soil and in them trans- 

 form to pupae. Three or four 

 weeks later the adult beetles shed 

 the pupal skins, but few of them 

 make their way to the surface 

 during the fall, most of them re- 

 maining in the pupal cells until 

 the following spring. 



Control. As they resemble the 

 white grubs in life-cycle, so the 

 means of control are similar. By 



plowing in late summer or early FlG - 58. A, beetle of wheat wire- 

 /ii JJ_T_ 111 / "worm i A OTZOICS 772/2 TICI^S) ^C4" B D 



tall and thoroughly harrowing for beetle (X4) and wireworm (X7) of 

 a month or SO, large numbers of Drasterius elegans; C, the corn wire- 

 ,i i ft worm (Melanotus cribulosus) 



the pupiE and newly transformed (After Forbes.) 



