14 BULLETIN 156, U. S. DEPARTMENT OF AGRICULTURE. 



In the spring of 1910 a large number of these larva? were col- 

 lected in the wheat fields at Govan and Wilbur, in "Washington State, 

 and confined in a root cage made by sinking a molasses barrel to the 

 level of the earth surface in a field at Govan and closing the top with 

 a short cylinder of sheet iron covered with wire gauze. The barrel 

 was filled with earth and wheat planted therein. The larva? could 

 easily be separated into three distinct groups, according to size, 

 which indicated a 3 years' life cycle. Later observations on the mate- 

 rial in the rearing cage proved this to be actually the case. 



Two lots of larvae were confined in this cage — one on April 14 

 and the other on April 30, 1910, so that all must have hatched from 

 eggs laid in 1909 or previous to that year. On June 21 the cage was 

 examined and a number of the larvae were found to be at from 4 to 

 8 inches below the surface, resting quietly in oval cells. They were 

 very fat at this time. The cage was not examined again until Xo- 

 vember 4, and at this time 3 adults, evidently of the 1907 genera- 

 tion, were found at about the same depth as the larvae observed in 

 June. They were still in the pupal cells, as was evident from the 

 last larval skins and the pupal skins found with them. The fol- 

 lowing spring (1911) the cage was examined on March 29. Several 

 larva? were found at this time. They were now moving actively 

 about in the soil and almost immediately attacked some seed wheat 

 sown in the cage on this date. An adult still in the pupal cell was 

 also found at this time. The cage was next examined on July 4, 

 at which time an adult was found on the surface of the ground. 

 Several full-grown larva? were also found on this date in their cells 

 at the usual depth of from 4 to 8 inches below the surface. These 

 were evidently the larva? hatched from eggs laid in 1908. On Au- 

 gust 17 the cage was examined and at about 5 inches below the sur- 

 face a pupa and an adult were found. The latter had evidently 

 just transformed, as it had not yet become quite black and was still 

 very soft. The following day the cage was entirely emptied and at 

 between 18 and 20 inches below the surface 10 larva? and an adult 

 were found in soil that was very hard, and very slightly moistened, 

 in fact merely moist enough to prevent its being absolutely dry. 

 The larva? seemed to be full grown and had evidently just completed 

 a molt, as they were quite soft. These were evidently of the 1909 

 generation. 



REMEDIAL MEAST7KES. 



As will be seen from the life histories of these two species, the 

 generations about to become adult are inactiAe larva? from June 

 to August and very delicate pupa? during the early part of the 

 latter month. These resting larva? and pupae are usually at a 

 depth of from 4 to 8 inches below the surface, and any disturb- 



