THE MELON FLY IN HAWAII. 21 



more than 120 hours without food but with water. Flies that had 

 been regularly fed for over 6 months did 'not live longer when de- 

 prived of food than those kept without food from emergence. The 

 rate of mortality among six lots of adults was as follows : 



(1) Twenty-five adults, emerging on January 3 and fed daily on papaya and 

 water until 9 -a. m., January 17, were placed in a clean jar immediately after 

 feeding. Thereafter they were given only water three times daily. One died 

 between 4 p. in., January 17, and 9 a. m., January 18 ; 1 between 2 and 3 p. m., 

 January 19, 2 between 4 p. in., January 19, and 9 a. in., January 20 ; 13 between 

 4 p. m., January 20, and 8 a. in., January 21 ; 1 between 11 a. m. and 12 m., 

 January 21 ; and 3 between 4 p. m., January 21, and 9 a. m., January 22. 



(2) Fifteen adults, which emerged June 22, 1915, and fed until December 13, 

 19J5, were placed at 9 a. m. of the latter date, immediately after being fed, in a 

 clean glass jar. All were dead by 8 a. in., December 17. Three died between 



1 and 4 p. m., December 14 ; 6 between 4 p. m., December 14, and 4 p. m., Decem- 

 ber 15 ; 3 between 4 p. m., December 15, and 8 a. m., December 16 ; 3 between 

 4 p. in., December 16, and 8 a. m., December 17. 



(3) Thirteen adults, emerging about 8 a. m., December 26, 1915, were placed in 

 a glass jar. These flies had no opportunity to feed after emerging. Two died 

 between 4 p. m., December 27, and 8 a. in., December 28; 8 between 4 p. m., 

 December 28, and 8 a. m., December 29 ; and 3 between 1 and 3 p. m., Decem- 

 ber 29. 



(4J Sixty-sis adults, emerging about 9 a. nx, December 30, 1915, were placed, 

 without having been fed, in a clean jar. Ten died between 9 p. m., December 31, 

 and 8 a. m., January 1, 1916 ; 28 between 9 a. m., January 1, and 8 a. in., January 



2 ; 3 between 3 and 6 p. m., January 2 ; 5 between 9 p. m., January 2, and 6 a. m., 

 January 3 ; and 1 between 1 and 3 p. in., January 3. 



(5) One hundred and forty-nine adults, emerging about 9 a. m., December 31,. 

 1915, were placed, without having been fed, in a clean jar. Ten died between 3 

 and 6 p. m., January 1, 1916 ; 19 between 9 p. m., January 1, and 8 a. m., January 

 2 ; 56 between 3 and 6 p. m., January 2 ; 47 between 9 p. m., January 2, and 6 

 a. m., January 3; 11 between 1 and 3 p. m., January 3; 5 between 4 p. in., 

 January 3, and 8 a. m., January 4; and 1 between 8 a. m. and 12 m., January 4. 



(6) Sixty-eight adults, emerging about 9 a. m., December 28, 1915, were 

 placed, without having been fed, in a clean glass jar. Two died between 4 p. m., 

 December 29, and 8 a. in., December 30 ; 8 between 1 and 4 p. m., December 30 ; 

 57 between 4 p. m., December 30, and 8 a. m., December 31; and 11 between 

 1 and 3 p. m., December 31. 



FOOD OF ADULTS. 



The food of the adult melon fly consists of plant juices, honey dew, 

 nectar, or even the juices of dead insects. In confinement the flies may 

 be seen occasionally feeding upon specimens which have died, 

 although this does not appear to be a universal habit. Severin (45) 

 has observed one adult feeding upon a dead and partly decomposed 

 caterpillar. The observations of the writers would indicate that 

 adults obtain the larger portion of their food from honeydew, and 

 especially from the juices exuding from the injured portions of their 

 hosts. Adults are found in large numbers on foliage covered with 

 the exudations of honeydew, no matter whether it is formed by the 



