52 



BULLETIN 491, IT. S. DEPARTMENT OF AGRICULTURE. 



quickly than the older pupae when submerged. Only 2 of 79 pupae 

 1 and 2 days old, respectively, survived submergence for 2 days. 

 Two out of 156 and 1 out of 163 pupse submerged 3 and 4 days, 

 respectively, survived. Other pupse 1 and 2 days old submerged 5, 6, 

 and 7 days died. 



It is safe to conclude that the larvae of the melon fly will be killed 

 when the host containing them is submerged in water for 5 days and 

 the pupae after submergence for 6 days. 



Table X. — Effect of submergence in ordinary soft water upon larvw of the 

 melon fly within encumbers. 





[ Daily mean temperatures 



for period 



69.5° to 71 



° F., averaging 70.5° 



F.] 











Dead larvae. 



Living larvse. 







Date of im- 



Date of re- 



Date of ex- 









Number 

 days im- 

 mersed. 



Number 











fruits ex- 

 amined. 



mersion. 



moval. 



amination. 



Third 



Second 



Third 



Second 









instar. 



instar. 



instar. 



instar. 







Jan. 15 



Jan. 16 



Jan. 17 



16 



15 



239 



63 



1 



22 



Do 



Jan. 17 



Jan. 18 



21 



19 



139 



52 



2 



37 



Do 



Jan. 18 



Jan. 19 



155 



46 



6 







3 



24 



Do 



Jan. 19 



Jan. 20 



256 



117 



1 







4 



29 



Do 



Jan. 20 



Jan. 21 



317 



197 











5 



41 



Do 



Jan. 21 



Jan. 22 



512 



261 











6 



61 



Table XI. — Effect of submergence in ordinary soft water upon pupw of the 

 melon fly at a mean temperature of 78° F. 



Lot No. 



Number 

 of pupae 

 under 

 observa- 

 tion. 



Date of 

 pupation. 



Date of 

 immer- 

 sion. 



Date of 

 removal. 



Number 

 of adults 

 emerg- 

 ing. 



Date of 

 emer- 

 gence. 



1 



396 



June 19-22 



June 24 



June 26 



9 

 90 

 108 

 19 

 4 

 3 

 1 



June 30 

 Julv 1 

 Julv 3 

 July 4 

 July 5 

 July 6 

 Julv 8 



2 



106 



do 



...do .... 



June 27 



32 



July 3 













15 



Julv 4 













8 



July 5 













4 



Julv 6 



3 



52 



do 



...do.... 



June 28 



2 



1 

 3 

 1 



Julv 3 



Julv 4 



July 5 

 July 6 

 July 7 



4 



77 



do 



...do.... 



June 29 



1 



July 10 



5 



91 



do 



...do 



June 30 









6 



79 



June 22-2-1 



...do 



June 25 



2 



July 5 



7 



130 



do 



...do 



June 27 



1 



Julv 7 



8 



26 



do 



...do 



...do 



1 



July 3 



9 



15 



do 



...do 



June 28 



1 



July 12 



10 



148 



do 



...do 



...do 









11 



101 



do 



...do 



June 29 









12 



117 



do 



...do 



June 30 









13 



170 



do 



...do 



July 1 









Burial in soil. — Van Dine (19) recommended that all melons and 

 vines infested with the melon fly should be buried to the depth of 

 several inches. Severin (45) has shown quite conclusively that 



