446 



Journal of Agricultural Research 



Vol. XV, No. 8 



The larvae of the second and third instars have not been distinguished 

 in any respect from those of D. tryoni. The mature larva, which is the 

 fourth instar, differs from the tryoni larva only in being faintly yellowish 

 in color and in having a slightly darker chitinization of the mandibles 

 (fig. 29). The mature larva of D. fullawayi also hibernates, but the per- 

 centage of larv^ hibernating appears to be less than occurs with D. 

 tryoni; the period of hibernation also is shorter. The greatest amount 



of adult emergence frotn hibernat- 

 ing individuals occurs during the 

 first three months after the larva ma- 

 tures. From 68 larvse passing into 

 a state of dormancy between August 

 I, I9i6,and July 31, 1917, inclusive, 

 29, 16, 21, and I pupated and be- 

 came adul'ts during the period from 

 ■ • the first to the fourth months, re- 



spectively. One individual hiber- 

 nated for 8 months and 15 days. 

 The greater proportion of the larv^ae 

 , under observation went into hiber- 

 nation during the months of Novem- 

 ber, December, January, February, 

 and March, and the greatest period 

 of adult emergence from hibernat- 

 ing material was in March, April, 

 and May. A much greater degree 



- .•»'' of hibernation occurs in fruit-fly 



,f»' 



^'*^ puparia left in soil or sand than ob- 



tains in dry glass vials. 



^t^^::Z:^'S'^£^:lt::, The pupa may be distinguished 



serosal cells still clinging to ventral surface. from that of D. tvyoni by the UUU- 



Lengt I mm. sually loug ovipositor sheath which 



extends back over the body almost to the head. The duration of the 

 pupa stage is the same as that of D. tryoni, as is also the duration of 

 the combined egg, larva, and pupa stages. 



ADULT 



The behavior of D. fullawayi after general distribution in Hawaii 

 is interesting. Localities having high humidity and precipitation have 

 proven especially favorable for this species. At points where the aver- 

 age humidity is low it has had evident difficulty in existing at all, 

 even under very favorable host conditions. An investigation of this 

 species in 191 7, after wide distribution and thorough establishment, 

 clearly indicated the particular capacity of this species for life under 



