THE MELON FLY IN HAWAII. 33 



tions made daily by H. F. Willard show that after 1 days 38 out of 

 174 eggs had hatched at this temperature, while of the 188 still un- 

 hatched 103 and 10, respectively, hatched after removal to normal 

 temperature on the fifth and sixth days. After days, 44 out of 

 64 eggs were found hatched in another lot of fruits examined, and 

 of the 20 eggs removed to normal temperatures but 1 hatched on 

 the seventh day after deposition. Examinations of fruit made after 

 the sixth day prove all eggs either to have hatched or died. 



In cold-storage experiments the egg stage was prolonged to at 

 least 12 days. Thirty-four eggs out of 107 in situ in pumpkins gath- 

 ered in the field May 11, 1914, and held in storage at 49° to 52° F. 

 until May 21, or for 10 days, hatched on May 22, or at least 11 days 

 after deposition. During summer temperatures the duration of the 

 egg stage may be likewise prolonged to as much as 10 days by sub- 

 jecting the host fruits containing the eggs to temperatures ranging 

 from £5 to 40° F. Table VIII contains data on the effect of cold 

 storage temperatures upon egg mortality. 



Table V. — Duration of the eyg stage of the melon fly at Honolulu. 



Number 

 of eggs 

 under 



observa- 

 tion. 



Eggs deposited. 



Day. 



Aug. 20 

 ..do..... 



...do 



...do 



...do 



...do 



...do 



...do 



...do 



...do 



...do 



..do..... 

 ..do..... 

 May 19 

 May 14 

 May 13 

 ..do 



Period. 



10.30 to 11.30 a. m... 



do 



do 



do 



do 



do 



do 



do 



do 



do 



do 



do 



do 



3.15 to 3.30 p. m 



4 to 6 p. m 



10 a. m. to 1 p. m 



do 



May 11 I 11.30 a. m. to 2 p. m. 

 ..do do 



Eggs hatched. 



Pay. 



Aug, 21 



..do 



...do 



...do.... 

 ...do.... 

 ...do.... 



.cio. 



...do 



...do 



...do 



...do 



...do 



...do 



May 20 

 Mav 16 

 May 14 



..do 



Mav 13 

 ..do 



Period. 



Average 



mean 

 tempera- 

 ture for 

 period. 



1 to 2 p. m 



2 to 2.15 p. m 



2.30 to 2.45 p. m.. 

 2.45 to 3 p. m 



3 to 3.15 p. m 



3.15 to 3.30 p. m.. 

 3.30 to 3.45 p. m.. 

 3.45 to 4 p. m 



4 to 4.30 p. m.... 



4.30 to 6 p. m 



6 to 8 p. m 



8 to 9 p. m 



9 to 10 p. m 



10 p. m. to 2 a. m 



3 to 5.30 a. m 



About 9 p. m 



10 p. m. to 3 a. m 



3 to 6 a. m 



6 to 9.30 a. m 



HATCHING. 



Several hours before hatching the dark-brown head-hooks of the 

 larva can be seen working backward and forward in a probable at- 

 tempt on the part of the larva to break its way through the egg mem- 

 branes. The head lies just back of the pointed anterior end of the 

 egg and the larva ultimately breaks through the inner membranes and 

 shell at this end and crawls out through the opening thus made. As 

 the larva pushes its way out. the rupture of the eggshell extends far- 



65732°— Bull. 491—17 3 



