MEDITERRANEAN FRUIT FLY IN HAWAII. 



59 



segments, and therefore bearing indications of the mouth opening and anterior spira- 

 cles of latter; last segment likewise bearing the remains of anal and stigmatal openings 

 of larva 



DURATION OF PUPA STAGE. 



Mally has found in South Africa, at Grahamstown, that the dura- 

 tion of the pupa stage may be as long as 35 days in a rearing box 

 kept " at the ordinary seasonal temperature." Martelli states that in 

 southern Italy the pupa stage varies with the progress of the season ; 

 that it maybe from 10 to 11 days during summer (August), 18 to 20 

 days during autumn (October), or 30 or more days during the winter. 

 Newman found in Western Australia the periods to be from 12 to 

 14 days during summer and 25 to 50 days during winter. Nearly 

 all writers have offered data on the duration of this stage, but, unac- 

 companied by temperature or 

 humidity records as they are, 

 they add nothing new to the 

 foregoing information. 



In a previous paper the 

 writers give data, accompanied 

 by temperature records, on ob- 

 servations including about 

 2,000 pupae developing under 

 Honolulu conditions. From 

 these it would appear that the 

 minimum length of pupal life 

 is about 6 days when the 

 mean temperatures range be- 

 tween about 76° and 79° F. 

 During the warmest Honolulu 

 weather the largest proportion 

 of any lot of pupae require 

 from 9 to 11 days before yielding adults. Thus at a mean of 

 about 76° F. 5, 14, 101, 160, 7, and 3 pupae yielded adults 6, 9, 10, 

 11, 12, and 13 days, respectively, after the formation of the puparium. 

 The pupa stage may be increased to at least 19 days when the 

 daily means drop to about 69° to 71° F. The data in Table XVI 

 covering observations on 7,000 pupse are given in corroboration of 

 this statement. At a mean temperature of about 66.8° F., pupae 

 required from 20 to 28 days to complete their development at 

 Kealakekua, Kona, Hawaii. In Table XVI are given a large number 

 of records covering the coldest portions of the year in the usual 

 fruit-growing sections of the islands. These records, together with 

 many others on file, given in Table XXV in connection with parasite 

 work, indicate that there occurs no dormancy among pupae at these 

 temperatures. In other words, while development is considerably 

 retarded, there is no yielding of adults by a few pupae while others 



Fig. 13.— Pupa of the Mediterranean fruit fly: a, Dorsal 

 view; 6, ventral view; c, posterior end, showing anal 

 scar and spiracles. (Original. ) 



