Feb. 15, 191S 



Mediterranean Fruit Fly 



365 



from various localitites. One box with a screen bottom of a sufficiently 

 large mesh contains the fruit and is placed over a box of the same size 

 containing sand. By this method the fruit does not need to be handled 

 daily, and the sand below is kept so dry that the larvae falling through 

 into it are easily sifted (PI. XLIV, fig. i). 



EMERGENCE OF hARVM AND PUPATION 



The larvse leave the fruit in largest numbers at or just after daybreak. 

 Thus, on the 6th of July, 16,624 larvse emerged between 4 and 9 a. m.,as 

 compared with 57 between 9 a. m. and 11 p. m. Siftings made at 6, 7, 8, 

 9, and 10 a. m., on July 7, yielded 1,006, 448, 171, 95, and 14 larvae, respec- 

 tively, during these hourly intervals. On July 8, at 5.20, 6, 7, 8, 9, and 10 

 a. m., 152, 978, 369, 72, 31, and 14 larvae, respectively, emerged, as com- 

 pared with 7 larvae during the rest of the day. The mean temperature 

 for the period of larval emergence during which these observations were 

 made ranged from 73° to 74° F. Nearly all puparia are formed in from 

 one to two hours during warm weather. 



LENGTH OF PUPAL STAGE 



From the data included in Table I it will be seen that the minimum 

 length of the pupal stage is 6 days when the mean temperature ranges from 

 about 76° to 79° F. During the warmest Honolulu weather the larger 

 proportion of any lot of pupae requires from 9 to 1 1 days before yielding 

 adults. This period may be increased to at least 19 days when the daily 

 means drop to about 69° to 71°. 



Table I. — Duration of the pupal stage of the Mediterranean fruit fly 



