74 BULLETIN 536, U. S. DEPARTMENT OF AGRICULTURE. 



deposited September 16 did not hatch. The temperature during this 

 period varied between 71 and 84° F., with a mean for the period of 

 78.5° F., and the relative mean humidity averaged about 66 per cent. 

 Two hundred females emerging November 13, 1914, were confined 

 without males and began ovipositing November 23, or after 10 days. 

 During this period the temperature ranged between 65 and 80° F., 

 with a mean of 74.6° F. ;.the relative humidity, averaging 69.2 per cent, 

 ranged between 52 and 85 per cent. Although no daily oviposition 

 records of these females were kept, 450 eggs deposited by them in 

 apples on 17 different occasions when they were given an opportunity 

 to oviposit between November 13 and March 4-5 failed to hatch. In 

 three other experiments not one of 2,264 eggs deposited by virgin 

 females hatched. 



Virgin females which have been depositing eggs that failed to hatch 

 may mate later and deposit fertile eggs. Thus 200 virgins emerging 

 on March 13, 1915, oviposited quite regularly until May 14, when males 

 were placed in the jar with them. Previous to May 14 all- eggs 

 deposited had failed to hatch. On May 16, 11 eggs were deposited; 

 of these all hatched but 2. 



INFLUENCE OF WEATHER CONDITIONS ON ADULT ACTIVITIES. 



No satisfactory data on this subject can be secured out of doors in 

 the Hawaiian Islands, as the colder temperatures which seriously 

 affect adult activities are not to be had except at higher altitudes, 

 where the fly is not to be found. At the Volcano House, Hawaii, at 

 about 4,000 feet elevation, where the November mean is about 60° F. 

 and the daily range is between 45° and 72° F., adults in jars were 

 inactive during the early mornings and late afternoons. During the 

 warmer period of the day adults became active and oviposited in 

 apples hung in their jars after the temperature reached 61° F. At 

 Honolulu, at a temperature of 65° to 67° F., 27 eggs were deposited 

 in peaches by about 40 females, and 40 eggs by a lot of 60 females. 

 At higher temperatures many more eggs would have been deposited 

 under otherwise similar conditions. Adults in jars were noted to 

 mate as usual on March 17, when the temperature was 69° F. On 

 March 18, 9 a. m., at 67° F., adults endeavored to oviposit in apples, 

 but did not seem to succeed in puncturing the skin. A female 

 emerging on August 12, 1914, was placed in a large glass refrigerator, 

 the temperature of which averaged 61° F., but varied for the period 

 between 58° and 62° F. She was accompanied by males and depos- 

 ited 3 and 6 eggs on September 12 and 20, respectively, but died on 

 September 25. This fly was replaced by another of like age, which 

 deposited 9, 5, 8, 4, and 6 eggs, respectively, on September 26, 27, 28, 

 29, and October 2. 



At a mean temperature of about 78° F., adults may deposit eggs 

 during the night, but deposition during this portion of the day has 



