July, 1914.] THE APPLE MAGGOT. 49 



in cages, large and small, the results are not sufficient in number 

 to warrant conclusions. 



On the basis of many field observations, however, it is clear 

 that the flies prefer sweet or aromatic fruit. This is shown in 

 the summary of comparative attack on various varieties and the 

 discussion of the characteristics of those attacked. So long as 

 such fruit is available the females will continue to oviposit in it 

 until individual apples may be fairly peppered with egg-punctures. 

 When such fruit is not available the females oviposit irregularly 

 and scatteringly. It has repeatedly been observed in New 

 Hampshire orchards that a tree of sweet or aromatic variety 

 standing among varieties of acid or subacid character will 

 to a considerable extent hold the attention of the females so 

 long as the fruit is available. If such a tree drops its fruit 

 early, or fails to fruit, the neighboring trees will then be attacked, 

 but not with the undivided attention accorded the favorite 

 variety. 



Flies Captured on Early Fruit Confined with Late Fruit. 

 That flies that are found about early fruit are able, though 

 perhaps not especially willing, to oviposit in late fruit, was 

 demonstrated in the following experiment : 



In 1910 several clusters of apples on Spy trees at Durham 

 were enclosed in cheese-cloth bags prior to the beginning of 

 emergence of adults. On August 9 several flies were captured 

 in an Orange Sweet tree, an early variety, the fruit being then 

 nearly ripe. The next day one pair of these flies was confined 

 in each of two of the limb-bags, and 7 flies in a third. In each 

 of the first two bags 1 apple was found with 1 egg puncture. 

 In the third 1 apple had 1 puncture, 1 had 2, and 1 had 4. 



NUMBER OF EGG PUNCTURES PER APPLE. 



In the course of the investigation there has been occasion to 

 examine large numbers of apples critically for egg punctures. 

 Many thousands of specimens were thus observed and recorded. 

 Detail records of various lots will be found elsewhere in this bulle- 

 tin, especially in the discussion of experiments with poison bait 

 sprays. It will be noted that the number of punctures per apple 

 sometimes reaches a high average — a fact not surprising to one 

 who has observed badly infested fruit. 



