38 



grown tomatoes matured in from 4 to 7 days; 5, 14, 9, and 2 develop- 

 ing in 4, 5, 6, and 7 days respectively, at an average mean tempera- 

 ture of 78.5° to 79.1° F. Under the same temperature conditions 

 4 and 5 larvae required 4 and 5 days, respectively, for development 

 in a ripe tomato. 



Lower temperatures than any experienced in Hawaii prolong 

 larval life, although to what extent it has been impossible to deter- 

 mine under out-of-door conditions, because host fruits of this pest 

 decay too rapidly. Eleven out of 23 larvae that were fully grown 

 when gathered in the field in pumpkins, on May 11, 1913, and placed 

 in a refrigerator kept at 49° to 52° F., were alive when examined on 

 June 3, or 23 days afterward, thus increasing the larval stage to at 

 least 28 to 30 days. At this same temperature, which is sufficiently 

 low to check development, 20 out of 62 first-instar larvae were alive 

 after 17 days in the refrigerator. These 20 larvae whose development 

 had been prolonged from about 12 hours to 17 days by the lower tem- 

 perature to which they had been subjected, after removal to normal 

 temperature of the laboratory continued their development at the 

 same rate and emerged as adults precisely as normal individuals 

 whose development had not been artificially arrested. 



Table VI. — Duration of the larval stage of the melon fly at Honolulu. 



Number 



Approximate period of 

 development. 



Host fruit. 



Number of hours in— 



Period in 

 larval stage. 



Average 

 mean 



of speci- 

 mens un- 

 der obser- 

 vation. 



Instar 

 1. 



Instar 

 2. 



Instar 

 3. 



tempera*- 

 ture for 

 period of 

 develop- 

 ment. 



1 



Sept. 18 to 22 



Ripe papaya 



do . 



24 



24 



24 



25 



27 



26 



24 



23 



23.5 



23.5 



22.5 



25.1 



36 



24 



25 



25 



25 



40 



24 



23.5 



22 



23.5 



23 



36 



36 

 50 

 54 

 51 

 60 

 52 

 60 

 60 

 60 

 60 

 60 

 60 



Days. Hrs. 

 4 



4 2 

 4 7 

 4 5 

 4 16 

 4 22 

 4 12 

 4 10 

 4 10 

 4 11 



4 11 



5 1 

 10 



13 

 6 

 7 

 8 

 7 



8 



9 



10 

 11 

 12 

 13 

 17 



5 



6 



7 

 8 

 9 



°F. 



78.2 



1 



Sept. 25 to 29 



79 



1 



do 



do 



79 



1 



do 



do 



79 



1 

 1 



Sept. 25 to 30 



do 



do 



do 



79 

 79 



1 



1 



Sept. 27 to Oct. 4 



do 



do 



do 



78.2 

 78.2 



1 

 1 

 1 

 1 



do 



do 



do 



do 



do 



do 



do 



78.2 

 78.2 

 78.2 

 78.2 



1 



Aug. 21 to 3! 





79 



1 



Aug. 21 to Sept. 2.. 



do 









79.2 



28 



Aug. 21 to 27 . 











79 



38 



Aug. 21 to 28.. 



. do .. 









78.8 



4 



Au?. 21 to 29 ... 



do 









78.8 



61 



Aug. 21 to 28. 



Ripe cantaloupe 



No. 1. 

 .... do 









78.8 



98 



Aug. 21 to 29 









78.8 



70 



Aug. 21 to 30 



do -. 







78.9 



18 



Aug. 21 to 31 



do 









79 



8 



Aug. 21 to Sept. 1 



Aug. 31 to Sept. 2 



do 







79 



2 



.....do 









79 



3 



Aug. 21 to Sept. 3. 



do 









79.2 



1 



Aug. 21 to Sept. 7 



Aug. 21 to 26.. 



do 









79.3 



12 



Ripe cantaloupe 



No. 2. 

 do 









79.1 



55 



Aug. 21 to 27 







79 



42 



Aug. 21 to 28 



do 





I 



78.8 



5 



Aug. 21 to 29 



do 







78.8 



1 



Aug. 21 to 30 









78.9 





I i 1 







