Nov. 25, 1918 Biology of Fruit-Fly Parasites in Hawaii 



431 



In the same months a quantity of paxasitized, freshly formed fruit-fly 

 puparia was placed in similar glass vials in a refrigerator running evenly 

 from 60° to 64° during the entire duration of the experiment. From this 

 material 384 adults of species of Diachasma emerged over a period some- 

 what retarded but not greatly prolonged, while 814 puparia failed to 

 produce anything and upon being opened on December 20 were found to 

 contain living, hibernating larvae of this genus. This represents a hiberna- 

 tion of 67.7 per cent of 

 all the material parasi- 

 tized by species of Dia- 

 chasma that was placed 

 in the refrigerator, and 

 is striking when com- 

 pared with the hiber- 

 nation of slightly over 

 I per cent among the 

 larvae of this genus held 

 at the same time at 

 a temperature about 

 1 3 degrees higher. 

 Another unknown 

 cause for hibernation 

 must exist, as mate- 

 rial kept beneath sand 

 or soil at any time of 

 the year produces a 

 greater degree of hiber- 

 nation than does mate- 

 rial held coincidently 

 at nearly the same 

 temperature but in dry 

 glass vials exposed to 

 light. 



^ ^ '-''^ Fig. 16. — Z)!acAa^ma irj'onj; Alimentary canal removed from a mature 



to 4 rnm. long by 1.6 pupa, showing the position and shape of the meconium. Greatly 



mm. wide and at first is '•'^^'^''^• 



pale white with reddish eyes. In a few days the adult colorations 

 appear. At pupation the old larval skin is split from the head back- 

 wards and slips back to the caudal tip of the pupa and is there immediately 

 pushed forward by the tips of the antennae of the male or ovipositor of 

 the female as these parts are forced forward over the dorsum of the 

 body. The exuvium then comes to rest as a yellowish, crumpled mass 

 at the tip of the ovipositor at a point generally over the pupal meta- 

 thorax and extending, in part, back along the side of the ovipositor, or, 



