36 BULLETIN" 640, TJ. S. DEPARTMENT OF AGRICULTURE. 



Attempts to control the Mediterranean fruit fly under Honolulu 

 conditions were unsuccessful. The number of adults killed was 

 great, yet a sufficient number survived to infest all fruits that ripened. 

 From what is known, however, of the benefits derived from these 

 sprays in other countries, there is no question but that poisoned-bait 

 sprays, when intelligently applied under such commercial conditions 

 as exist in California and Florida, will prove successful. Thus Mally 

 in South Africa states that a "severe outbreak of the pest in a commer- 

 cial peach orchard was brought to a sudden and practically complete 

 halt, and the fruit maturing later was marked under the guarantee of 

 freedom from maggots," while the infestation among fruits on check 

 trees increased until all fruits became infested. Newman in Western 

 Australia estimates the cost of spraying an acre when one applica- 

 tion of one pint of spray per tree is made every 12 to 14 days to 

 be from SI. 50 to $2 per fortnight, and states that this sum is a mere 

 bagatelle to the loss of fruit during a similar period over a like area. 

 Both Mally and Newman, working under conditions of less rainfall 

 than obtained at Honolulu, and more like those of California and of 

 fall and winter in Florida, believe that good results will follow the 

 consistent application of poisoned bait sprays, particularly when 

 supplemented by the proper destruction of infested fruits. 



Honeybees are not endangered by the application of poisoned- 

 bait sprays. 



COLD-STORAGE TEMPERATURES. 



• 



Cold-storage temperatures do not lessen the damage already done 

 fruits by larva? within them, but they may become of inestimable 

 value in guarding fruits against further attacks while in storage or 

 transit and in freeing them from suspicion as carriers of the fruit fly. 



For the details of the effect of cold-storage temperatures upon 

 eggs, larva?, and pupa? of the Mediterranean fruit fly, application 

 should be made to the Bureau of Entomology for articles already 

 published. Fruits of almost any variety commonly held in storage 

 are held at temperatures varying from 32° to 45° F., with preference 

 shown to a range of 32° to 36° F. It may be said that no immature 

 stages of the Mediterranean fruit fly can survive refrigeration for 

 seven weeks at 40° to 45° F., for three weeks at 33° to 40° F., or for 

 two weeks at 32° to 33° F. 



It seems reasonable to conclude that sooner or later the certifica- 

 tion of properly refrigerated fruit will be practicable. When an 

 association of fruit growers, or a people, find it financially worth 

 while, there is no reason why they can not operate a central refrigera- 

 tion plant under the supervision of an official whose reputation shall 

 he sufficient to guarantee all fruits sent out from the plant to be 

 absolutely. free from danger as carriers of the fruit fly. 



