58 



BULLETIN 536, U. S. DEPARTMENT OF AGRICULTURE. 



Table XV. — Showing ability of low temperatures to lengthen larval life of the Mediter- 

 ranean fruit fly } 



Number of 

 specimens 

 under ob- 

 servation. 



Instar. 



Locality. 



Temperature. 



Range. Mean. 



Length of 

 instar or 

 instars. 



2 



3 



2 



3 



3 



3 



3 



3 



1,2,3 



L2,3 



1,2,3 



1,2,3 



1,2,3 



1,2,3 



1,2,3 



1,2.3 



1 



1 



1 



1 



1 



1 



1 



2 



2 



1 



1 



1 



1 



1 



Cold storage 



Refrigerator No. 1 . 



RefrigeratoT No. 3. 



Kealakekua . 



Hualalai. 



°F. 

 33-38 

 33-38 

 40-45 

 40-45 

 48-54 

 48-54 

 48-54 

 48-54 

 f 58-62 

 58-62 

 58-62 

 58-62 

 58-62 

 58-80 

 58-80 

 58-80 

 27-73 

 27-73 

 27-73 

 27-73 

 27-73 

 27-73 

 27-73 

 27-73 

 27-73 



Puulehua. 



Days. 



S-Strawberrv. 



/ 39-79 

 I 39-79 



1 In securing these data apples were used as host fruits in all but the first four records for cold storage, 

 for which peaches were used. 



In spite of the ability of cold temperatures to prolong larval life 

 greatly beyond the usual period required for development during 

 warm Hawaiian weather, it is interesting to record that individual 

 larvae whose development has been slowed down, or even practically 

 suspended, will continue their development normally when returned 

 to warmer temperatures. Thus one second-instar larva which had 

 been held for 54 days on Hualalai on being taken to Kealakekua on 

 March 26, where the mean temperature was about 66.8° F., and then 

 to Honolulu on March 29, molted into the third instar on March 30. 

 A second larva placed on Hualalai just after hatching and kept there 

 until March 17, or 45 days, on being taken to Kealakekua molted 

 into the second instar on March 21, into the third instar on March 

 24, pupated March 28, was taken to Honolulu on March 29, and 

 emerged as an adult on April 10. 



PUPA. 



DESCRIPTION OF PUPARIUM. 



Pwparium (Fig. 13, a, b, c). — Puparium elliptical in general shape; a little more 

 convex on the dorsal side; length about 4 to 4.5 mm. The size and color of puparium 

 vary and depend upon the amount and nature of larval food . Puparia formed by larvee 

 feeding on coffee cherries dull white; the usual color light or dark testaceous. There 

 are only 11 distinct segments, the first being composed of the first and second larval 



