INSECTS 207 



warrant measures to prevent its recurrence. The worms have some 

 parasites that help to reduce their numbers. They also have the 

 habit of dropping to the ground when subjected to a sudden jar, 

 just as does the plum curculio ; thence, if the worms become 

 numerous, jarring upon sheets could be profitably practiced except 

 for very large trees. 



Apple maggot (Rhagoletis pomonella). This insect has come 

 under my notice only in apples from the Eastern states. In 1867 

 B. D. Walsh 1 described the insect from flies bred from Eastern 



Fig. 91. The work of the apple maggot 



Early harvest apples badly affected with maggots. (Department of Entomology, 

 Cornell University) 



apples and from native haws, and since that time it has been 

 frequently reported as a serious pest in New York and in most of 

 the New England States. In 1884 it was reported to be doing 

 great damage in Michigan. 



For some reason not readily explained the insect has failed to 

 become generally disseminated in the Middle Western states. Most 

 reports of serious injury come from New York and other more 

 eastern states. These reports agree (1) that the insect spreads 

 slowly and may infest a few trees in an orchard for several years 

 without spreading to neighboring trees ; (2) that summer and fall 

 apples suffer much more than do winter varieties ; (3) that there 



1 i;. I). Walsh. Illinois state horticulturist. 



