The Currant Fruit Fly. 



TABLE 13. 



Number of Eggs and Ovarioles in Ten Currant Fruit Flies. 



205 



Date, flies 



Ovarioles 



Left 



Total 



Number of 



were mating 



in right 



in 



ripe eggs 



in field 



ovary 



ovary 



both 



in ovaries 



June 7 



16 



16 



32 



4 



7 



17 



17 



34 



17 



8 



ir. 



15 



31 



3 



8 



15 



16 



31 



10 



8 



17 



15 



32 



10 



8 



16 



17 



33 



5 



8 



17 



17 



34 



5 



8 



17 



17 



34 



7 



8 



17 



18 



35 



8 



8 



18 



18 



36 



4 



Average 



16.6 



16.6 



33.2 



7.3 



If the five egg's present in each of the 33 ovarioles were to 

 reach maturity, the female would be able to deposit 165 eggs ; 

 but since many more eggs may be developed in the terminal 

 chamber, the question of the number of eggs that a fly may lay 

 remains doubtful. 



Daily Rate of Oviposition. 



An attempt was made to ascertain the daily rate of oviposi- 

 tion under laboratory conditions. Three pairs of currant fruit 

 flies in coition were confined in three glass jars. The bottom of 

 each container was covered with about an inch of moist sand, 

 in which was embedded a small bottle of water containing the 

 stems of gooseberry twigs heavily laden with fruit. At the end 

 of each day the twigs were removed and replaced by others cut 

 from a screened gooseberry bush. The trypetids were fed daily 

 on diluted corn syrup. Several times during each day water 

 was applied to the cheese cloth enclosing the top of the jars. 

 Table 14, shows the daily rate of oviposition. 



