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



flies may begin to appear the last week in June. In late seasons, 

 or when other conditions tend to delay emergence flies may not 

 begin to appear until the second week in July. The flies nor- 

 mally emerge in largest numbers in the second and third weeks 

 in July. This is approximately' true even when the beginning 

 of emergence has been delayed, in this case the flies appearing in 

 rapidly increasing numbers as soon as emergence is once started. 

 In the last week of July the number of flies appearing quickly 

 diminishes to a small fraction of the figures for the period pre- 

 ceding, and is practically at an end by the middle of August, but 

 straggling individuals may continue to appear from time to time 

 throughout the latter month. In New Hampshire there is no 

 second period of emergence in August or at any other time in the 

 latter part of summer. There is no evidence of a second brood. 

 Emergence in 19 lo. Partial records only were secured in 



1910 showing the dates of emergence of adults. 



In experiments to determine the depths from which adults can 

 make their way out, pupae were buried at various depths in the 

 soil. These were not in normal surroundings as regards sunlight. 

 Emergence of adults from these pupae began July 9, and was at 

 the approximate maximum about July 15. 



In June, 1910, a ground cage was placed in the open in Strafford, 

 N. H., over soil containing numerous pupae. An apple tree had 

 stood at this place the previous year, but had been cut down. The 

 cage used had wood sides and top, with two mica chimneys 

 fixed in holes in the top. Adults were noted in the chimneys on 

 June 30. This and succeeding records at this point were not 

 made by members of the department. 



Emergence in 191 1. In the summer of 1910 preparations 

 were made for observing the dates of emergence of the adults in 



1911 by placing 13 lots of badly infested apples in heaps on the 

 ground, and allowing these to rot undisturbed. Twelve of these 

 lots were on sod and one on cultivated ground. 



In addition, on June 19, 1911, 200 pupae were buried just be- 

 neath the surface in 8 of the lots. These were miscellaneous 

 pupae secured in the course of experiments of the previous fall. 



In order to secure the adults emerging, cages were placed over 

 each location. All adults were removed daily, except on three 

 dates. All cages were at least three feet square and had 



