50 



BULLETIN 491, U. S. DEPARTMENT OF M3RICULTUBE. 



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

 33° to*36° F., or 21 days at 38° to 10° F. No larva) of the melon 

 fly survived more than 11 days of refrigeration at 35° to 36° F., or 

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

 than L2 days at 31° to 30° F., 11 days at 36° to 40° 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 larva? 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 larvce 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 inst ar. 



Number 

 alive. 



Number 

 dead. 



Number 

 alive. 



Number 

 dead. 



Number 

 alive. 



Number 



dead. 



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 



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 



1(17 



78 



96 



35 



48 



64 



21 











13 



63 



6 



44 







8 



48 

 2 

 

 

 

 

 

 

 12 

 43 

 

 5 

 

 

 

 

 

 

 

 

 

 

 



1 



66 

 2 

 



: 



364 



215 



299 



288 



363 



379 



265 



49 



34 



114 



78 



105 



45 



104 



155 



82 



126 



130 



122 



126 











30 



16 



9 



4 











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 













 250 







