114 BULLETIN 536, U. S. DEPARTMENT OF AGRICULTURE. 



The examination of various host fruits submerged in ordinary tap 

 water, when the temperature ranged between 67° and 80° F., gave 

 the data recorded in Table XXXI. The data indicate that while 

 larvae are little affected after 1 or 2 days of submergence, a large 

 percentage are dead after submergence for 3 days. Seventeen second- 

 instar larvae and 1 third-instar, however, were found living after 

 submergence for 4 days. It is safe to conclude that submergence 

 for 5 days will either kill all larvae or incapacitate them for further 

 development. It might be added that fruits held in water for as long 

 as 3 to 5 days are, in Hawaii, rendered unfit as food for fruit-fly larvae 

 after removal from water. 



Table XXXII. — Effect of submergence in tap water upon pupae of the Mediterranean 



fruit fly. 



Lot 

 number. 



Number 

 ofpupee 

 under ob- 

 servation. 



Number 

 of days 



im- 

 mersed. 



Date of 

 pupation. 



Date of 

 immer- 

 sion. 



Date of 

 removal". 



Number of 



adult 

 C. capitata 

 emerging. 



Number of 



adult Opius 



humilis 



emerging. 



Date of 

 emergence. 



1 



1,016 



440 



312 



410 

 258 

 214 



950 

 460 

 210 



557 



37.2 

 476 



2 



3 



4 



5 

 6 



7 



2 

 3 

 4 



5 



6 



7 



June 14-17 

 do 



June 24 

 ...do 



June 26 



June 27 



June 28 



June 29 

 June 30 

 July 1 



June 26 

 June 27 

 June 28 



June 29 



June 30 

 July 1 



f 650 

 191 



1 4 



3 



15 

 18 

 16 

 1 

 

 3 

 1 

 

 

 1 

 

 

 

 

 5 

 7 

 18 

 8 

 

 2 

 



June 27-28 

 June 29. 

 June 30. 





July 4. 





' 



July 5. 



2 



62 



{ i 







1 







f 32 



207 



190 



156 



39 



6 



18 



64 



76 



41 



16 



9 



3 



1 



25 



23 



9 



17 



19 



1 



2 



19 



19 



42 



18 



22 



5 



13 



6 



3 



3 







July 1. 

 July 2. 



3 



do 



do 



do 



do 



June 17-22 

 do 



...do 



...do 



...do 

 ...do 



...do 

 ...do 



July 3. 

 Julvi. 

 Julv 2. 



4 



July 4. 





July 7. 



6 





7 



June 29. 

 June 30. 

 July 1. 

 July 3. 





July 4. 

 July 5. 

 July 6. 

 July l. 

 July 3. 







July 4. 



8 





July 5. 

 July 6. 

 July 9. 





do 



...do 



1 







July l. 







July 3. 



9 



3 

 2 



July 4. 

 July 5. 





do 



...do 



July 6. 





1 

 1 



July 7. 

 Julys. 

 July 3. 

 July 4. 

 July 5. 











10 





July 6. 





do 



...do 





July 7. 

 July 8. 

 July 9. 

 July 7. 

 July 8. 

 July 10. 

 July 12. 



















11 







do 



...do 





12 















Total.... 



5,675 





Pupae from 1 to 4 days old were submerged in vials of tap water 

 when the temperature ranged from 72° to 85° F. A record of the 



