July, 1914.] THE APPLE MAGGOT. 35 



It has already been noted that among winter apples Baldwin, 

 Northern Spy, R. I. Greening and King are in comparative 

 abundance in New Hampshire orchards, especially Baldwin. 

 Undoubtedly these varieties, notably the Baldwin, are often 

 found infested in part because of the condition indicated above. 



LIFE HISTORY STUDIES IN NEW HAMPSHIRE. 



For the most part the life history studies here described were 

 carried on at one or more of three places, as follows: in the vicinity 

 of Durham; in a section known as Beauty Hill, seven miles north- 

 west of Durham; and at another point known as Sunnyside, two 

 miles farther northwest. 



The altitude at the latter two places is greater than that of 

 Durham, which is about thirty feet above sea level, and the 

 summer season usually begins appreciably earlier and lasts longer. 

 Other conditions in the three places are about the same, and do 

 not differ materially from conditions at most other points in 

 southern New Hampshire. Some observations were made at 

 various other points in the southern half of the state. 



The cages and other apparatus will be described in the discus- 

 sion of the various experiments in which they were employed. 



Nearly all the life history work was performed in the open, in 

 or about orchards, under conditions and surroundings believed 

 to be entirely normal. Some experiments, as noted in the dis- 

 cussions that follow, were carried out in the open-air insectary 

 belonging to the department of entomology. This building is 

 fully described in the Journal of Economic Entomology, Vol. 2, 

 page 389. In brief the work-room has screen sides and a double 

 canvas roof with air-space between. The floor is partly of con- 

 crete, partly earth that is continuous with the ground beneath. 

 Moisture appears normal in this earth at a depth of a few inches. 

 Temperature and humidity in the work-room are normal. In 

 winter, in these experiments, the canvas roof and screen sides 

 were removed. 



THE ADULT— DATES OF EMERGENCE. 



In New Hampshire normal emergence of adults of the apple 

 maggot begins the first week of July. When the season is ad- 

 vanced, or when other conditions tend to accelerate emergence, 



