JOURNAL OF AGRICETIAL RESEARCH 



DEPARTMENT OF AGRICULTURE 

 Vol. VI Washington, D. C, May 15, 1916 No. 7 



EFFECT OF COLD-STORAGE TEMPERATURES UPON THE 

 PUP^e OF THE MEDITERRANEAN FRUIT FLY ^ 



By E. A. Back, Entomologist, and C. E. Pemberton, Scientific Assistant, Mediter- 

 anean and other Fruit-Fly Investigations, Bureau of Entomology 



INTRODUCTION 



The use to which cold-storage temperatures may be put as an aid in 

 offsetting the disastrous results of attack by the Mediterranean fruit fly, 

 Ceraiiiis capitata Wied., has already been made the subject of discussion 

 by the writers.^ In their paper, however, data on the effect of various 

 ranges of temperatures used in commercial cold-storage plants upon the 

 eggs and larval instars only are given. So far as the writers have been 

 able to determine, 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°. The effect upon over 26,000 eggs and 

 60,000 larvae of different temperatures, including 32°, 32° to 33°, 33° to 

 34°, 34° to 36°, 36°, 36° to 40°, 38° to 40°, and 40° to 45°, indicate that 

 no eggs or larvae survive refrigeration for seven weeks at 40° to 45°, for 

 three weeks at 33° to 40°, or for two weeks at 32° to 33°. 



While the greatest danger in the spread of this pest from one country 

 to another lies in the transportation of the larvae within fruits, there are 

 certain data on record which prove that this pest may be carried long 

 distances in the pupal stage and arrive at its destination in a condition to 

 produce infestation. A fruit-fly pupa (species unknown) was found at 

 Auckland, New Zealand, in soil about the roots of plants imported from 

 Australia.^ In 1914, Sasscer'* records the discovery in Washington, 

 D. C, of living pupae of the papaya fruit fly (Toxotrypana curvicavda 

 Gerst.) in a package containing an unknown vine from Mexico. In 



1 The writers wish to acknowledge the assistance given them by Mr. H. F. Willard in obtaining the data 

 recorded in this and in their previous paper. To obtain these data has necessitated much prolonged tedious 

 work extending over three years. In securing the data during 1915, Mr. Willard has not only greatly 

 assisted, but on several occasions during the absence of the writers has been entirely responsible not only 

 for the completion of experiments already started, but for the starting of others. 



' Back, E. A., and Pemberton, C. E. Effect of cold-storage temperatures upon the Mediterranean fruit 

 fly. /n Jour. Agr. Research, v. 5, no. 15, p. 657-666. 1916. 



3Kirk,T.W. Fruit flies. New Zeal. Dept. Agr. Div. Biol. Bui. 22, p. 9. 1909. 



* Sasscer, E. R. Important insect pests collected on imported nursery stock in 1914. In Jour. Econ. 

 Ent,, V. 8, no. 2, p. 268-270. 1915. 



Journal of Agricultural Research, Vol. VI, No. r 



Dept. of Agriculture, Washington, D. C. May 15, 1916 



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