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



From these experiences the deduction was made that such sur- 

 roundings may bring about an approximation of a general dis- 

 persion. 



Experiments in 1911 and 1913. In 1911 and in 1913 various 

 experiments were undertaken intended to furnish direct data 

 as to the dispersion habits of the flies. It was hoped to prove 

 how far they might or might not travel, but evidence of a pre- 

 cise nature was not obtained. 



In the first experiment, at the Beauty Hill locality, 76 flies 

 were released beneath one of a small group of late trees. Later 

 100 apples from this tree were examined and 12 egg punctures 

 found. From a tree fifty feet away 100 apples were examined, 

 and 14 egg punctures found. Other trees in the group gave 

 similar results. 



In a row of Baldwin trees along a stone wall at Durham 75 

 flies were released beneath one of the trees July 7, 1911. An 

 examination of the fruit later showed the following records. 

 From the tree beneath which the flies were released 176 apples 

 gave 263 punctures; from a tree twenty-five feet away 96 apples 

 gave 88 punctures; from a tree twenty-five feet away in the 

 opposite direction 125 apples gave 47 punctures; from a tree 

 fifty feet away 137 apples gave 214 punctures; from a tree 

 seventy-five feet away 158 apples gave 50 punctures. There 

 is of course no proof that the egg punctures found were the 

 work of the flies released. 



Other similar experiments at two other points at Durham gave 

 similar indefinite results, which could be interpreted, if at all, 

 as merely indicating that the flies released beneath late trees 

 did not concentrate and lay an abundance of eggs in the fruit 

 of the tree in which they were let loose. 



In August, 1913, an experiment was tried of releasing marked 

 flies. One hundred flies caught in apple trees in the Beauty Hill 

 locality were marked by amputation of one leg of each. These 

 flies were then released 350 feet from a small orchard owned by 

 the station. The wind was blowing moderately toward the 

 orchard. Search in the orchard for marked flies was made at inter- 

 vals for several days, but none were observed. 



In a similar experiment later 50 flies marked in the same manner 

 were released 200 feet from the orchard, the wind blowing stead- 

 ily at the time toward the point of observation. No flies were 

 recovered in the orchard. 



