50 



BULLETIN 491, IT. S. DEPARTMENT OF AGEICULTUEE. 



entirely killed until refrigerated for 10 days at 32° F., 18 days at 

 33° to 36° F., or 21 days at 38° to 40° F. No larvae of the melon 

 fly survived more than 14 days of refrigeration at 35° to 36° F., or 

 36° to 40° F. ; no larvae of the Mediterranean fruit fly survived more 

 than 12 days at 31° to 36° F., 11 days at 36° to 10° F., or 20 days 

 at 38° to 40° F. No eggs of the melon fly survived cold storage at 

 35° to 36° F. and 36° to 40° F. for more than 10 days, while no 

 eggs of the Mediterranean fruit fly were found alive after refrigera- 

 tion at 36° F. and 36° to 40° F. for 12 days. 



It is anticipated that these data will be of special value from a 

 quarantine standpoint. The favorable host fruits of the melon fly 

 are fruits which do not adapt themselves to long periods of refrig- 

 eration and are subject to serious attack only when they are very 

 young and succulent, except such fruits as the cantaloupe, cucumber, 

 and tomato. The melon-fly host fruits are classed among the quickly 

 perishable fruits, unless exception be made of certain varieties of 

 well-matured squashes and pumpkins. In experimental work the 

 writers have had difficulty in keeping host fruits in fit condition until 

 the larvae infesting them had been killed by refrigeration. This 

 was particularly true at the temperature of 49° F. 



Table VIII. — Effect of cold-storage temperatures upon eggs and larvm of the 



melon fly. 



Number 

 of days 

 in cold 



storage. 



Temper- 

 ature of 

 storage. 

 room. 



Eggs. 



Larva?. 



Number 

 under 



observa- 

 tion. 



Number 

 hatching 



after 



removal 



from 



store. 



First instar. 



Second instar. 



Third instar. 



Number 

 alive. 



Number 

 dead. 



Number 

 alive. 



Number 

 dead. 



Number 

 alive. 



Number 

 dead. 



7 



10 



12 



14 



16 



18 



20 



22 



6 



7 



9 



10 



11 



12 



13 



14 



15 



17 



18 



20 



22 



7 



8 



9 



10 



12 



17 



21 



23 



°F. 

 35 to 36 



3 



67 

 172 



47 

 52 

 32 





 31 

 75 

 14 

 78 





 147 





 78 







72 



135 















87 

 83 

 282 

 107 

 31 

 72 





 250 



1 

 

 

 

 

 

 

 

 15 

 

 1 

 

 

 

 

 

 

 

 

 

 



1 









 34 

 

 





 



8 

 1 

 

 

 

 

 

 

 85 

 19 

 

 

 

 

 

 

 

 

 

 

 

 

 

 51 

 16 

 

 20 

 

 



64 



595 



260 



172 



85 



263 



243 



134 



124 



10 



65 



49 



124 



60 



107 



78 



96 



35 



48 



64 



21 











13 



63 



6 



44 







8 



48 

 2 

 

 

 

 

 

 



12 



43 

 

 5 

 

 

 

 

 

 

 

 

 

 

 

 1 



66 

 2 



77 

 364 

 215 

 299 

 288 

 363 

 379 

 265 



49 



34 

 114 



78 

 105 



45 

 104 

 155 



82 

 126 

 130 

 122 

 126 

 

 



30 



16 

 9 



89 



14 



4 























12 



25 



2 



51 







5 







1 































17 



74 



32 



19 



80 



11 



145 



440 



218 



336 



301 



815 



676 



318 



13 



63 



18 



223 



140 



186 



26 



320 



84 



61 



291 



258 



108 











11 



12 



49 



10 



76 



12 















36 to 40 

























49 to 52 



49 to 52 







i 4 

 

 













