48 CIRCULAR 2 7 0, U. S. DEPARTMENT OF AGRICULTURE 



with a dormant-season spray containing 3 or 4 percent of oil emulsion, 

 as used for scale insects, or by means of the summer sprays just 

 mentioned. 



Cherry Fruitfly 



The maggots of the cherry fruitfly (Rhagoletis cingulata Loew) are 

 very injurious to cherries in western Oregon and Washington. They 

 have also been found in parts of Idaho, eastern Oregon, and in Spo- 

 kane, Wash., but have not become numerous in these localites. The 

 injury is especially severe in years when the cherry crop matures late, 

 since a late season apparently delays the fruit more than it delays 

 the flies, and gives them the opportunity to infest the main crop of 

 cherries. In normal years the maggots live chiefly in seedlings and 

 late varieties. The young maggots begin to feed about the cherry pit, 

 and the flesh of an infested cherry may be separated from the pit very 

 easily, which cannot be done with a cherry that is not infested. 

 This feeding may be done before there are any 

 outward signs of infestation, and often before the 

 maggots are large enough to be seen easily. Later 

 on the cherry begins to shrivel on one side, the flesh 

 is found to be more or less decayed, and small 

 holes appear in the skin. At this stage the white, 

 nearly full-grown maggot may readily be found in 

 the fruit ; usually there is only one, but sometimes 

 two or more. The maggots are more easily seen 

 in the dark-meated varieties of cherries such as 

 the Lambert and the Late Duke, and the impres- 



Figure 56. Cherry sio n that white cherries are not seriously infested 



fruitfly. x 5. * may be gained. However, careful examinations 



have shown that the white cherries are often 



infested just as much as the black ones. The infestation at times 



amounts to 75 to 90 percent of the crop. This insect is a native of the 



Eastern States. 



LIFE HISTORY 



The maggots pass the winter in the soil, in small, hard, brown cases 

 known as puparia. These are produced by the shrinking and drying 

 of the outer skin of the maggot. The flies (fig. 56) emerge from the 

 ground during June or July, and fly about in the sun for some days, 

 feeding on any moisture or honey dew that may be on the trees. 

 After a few days the females lay eggs in the cherries, piercing the skin 

 of the fruit with their ovipositors and depositing the eggs in the flesh. 

 The very small white maggots hatch in a week or less and immediately 

 begin to feed about the pit. Feeding continues for about 2 weeks, 

 and when fully grown the maggots, which are about one-fourth of an 

 inch long, drop to the ground and form their puparia a few inches 

 beneath the surface. They remain there until the following spring. 



CONTROL 



Thorough cultivation undoubtedly destroys some of the puparia 

 in the soil, but it does not reach enough of them to be of much value. 

 Since the maggots hatch within the fruit and are protected hj it while 



