110 N. H. AGR. EXPERIMENT STATION. [Bulletin 171 



In experiments in 1910 at Durham 5 lots of 20 pupse each were 

 buried in sandy soil at depths of 10, 8, 6, 4 and 2 inches. The 

 number of adults emerging from these respective lots was 19, 

 14, 10, 15 and 16. Similar results were secured from another 

 experiment. 



In 1911 five lots of pupae of 150 each were buried in moist loam 

 at depths of 15, 12, 9, 6 and 3 inches. The emergence of adults 

 from these lots was, respectively, 29, 57, 36, 42 and 69. In other 

 words there was an emergence of over 19 per cent from a depth 

 of 15 inches. 



Ross (55, p. 68) buried 100 pupse at a depth of 6 to 7 inches, 

 and 100 more at a depth of 12 inches. Of the former 41 adults 

 emerged, and of the latter 19. 



COMPACTING THE SURFACE SOIL. 



In 1911 three lots of 200 pupae each were buried three or four 

 inches below the surface in a loam soil. In two of these lots the 

 soil was then watered and pounded so as to compact the surface. 

 The remaining lot was left as check. 



Screen wire cages were placed over each area, and the emer- 

 gence of adults recorded. 



In one of the lots of compacted soil 1 adult emerged; in the 

 other, none. In the check cage 64 adults emerged. 



At another point three similar lots of pupae were buried in a 

 soil of exceedingly stiff clay. The ground was so hard that a 

 pick was used to loosen it, in order to bury the pupae. This 

 ground was treated in similar fashion to that described above. 

 In the two treated areas no adults emerged. In the area not 

 treated 3 adults appeared. 



The first experiments seemed to indicate that wetting and 

 pounding the surface may have some effect on successful emer- 

 gence of the adults. As a practical measure, however, in the 

 opinion of the writer it would seldom prove feasible. In addi- 

 tion, the results given are complicated by the possibility that 

 part of the pupae used may have represented the two-year life 

 cycle, and by the additional fact that predaceous beetles were 

 at work in the soil in this particular experiment. 



