184 



Maine Agricultural Experiment Station. 1917. 



of the host plant bearing unripe fruit, in a breeding jar con- 

 taining fruit flies which had been captured in the field. The 

 bottom of the jar was covered with about an inch of moist sand 

 and in this was embedded, a small bottle of water containing 

 the stems of the plants. The twigs were allowed to remain in 

 the breeding jar for a day and were then transferred into another 

 jar which did not contain flies. At the bottom of the second 

 jar rested a bottle filled with water and in this, the ends of the 

 stems were emersed. The duration of the egg and larval periods 

 in cultivated and wild gooseberries, white and red currants, and 

 the mountain currant (Ribes alpinum Pursh) under laboratory 

 conditions is shown in table 2. 



TABLE 2. 



Egg and Larval Periods Under Laboratory Conditions. 



Kind of Fruit 



O o O 



^B::. 





Pa2 



T o 



W ft' 



Gooseberry 



Gooseberry 



Wild goossberry. 

 Wild gooseberry- 



White currant-- 

 White eurrant- 



White currant- 

 Bed currant— 



8ed eurrant- 



June 22 



June 23 



June 30 

 June 23 



June 29 



4—5 



June 20 i 5-t6 



Jung 21 ! 4—6 



June 21 4—5 

 June 28 4—6 



4—6 



4r-5 



4—6 



Mountain currant June 18 7 



Mountain currant July 6 5 — 6 



July 8 

 9 



10 



11 



12 



July 9 



10 



11 



12 



July 8 



9 



-July 7 



10 

 11 



July 7 

 9 



July 15 

 17 

 IS 



July 17 

 19 



July 9 

 10 

 11 

 13 



July 1.5 

 16 

 17 

 18 

 20 



July 9 

 10 

 11 



July 28 

 29 



11—15 



12—14 



11—16 



11—15 



10—17 



14—16 



16—18 



16—20 



16—19 



18-19 

 16—20 



16—18 

 17—20 



17—19 

 16—20 



16—21 



21—28 

 22—23 



