April, '16] BACK AND PEMBERTON: CERATITIS PARASITISM 307 



While the export trade of the Islands in fruits except the banana 

 and pineapple has been destroyed by the horticultural quarantines 

 following the advent of this pest, it is hoped that the introduced para- 

 sites may be sufficiently effective to make possible the growing 

 for home consumption of certain fruits now always badly infested. 



Having undertaken an investigation of the Mediterranean fruit-fly 

 in Hawaii for the Bureau of Entomology in 1912, the writers have had 

 an excellent opportunity to follow the progress of parasitism of this 

 pest. Their work during 1912 and 1913 makes it absolutely certain 

 that no parasitism existed among the eggs, larvae or pupae up to the 

 time when Dr. Silvestri arrived with his parasites. In their paper 

 entitled "Parasitism among the Larvae of the Mediterranean Fruit- 

 fly (C. capitata^ in Hawaii during 1914," published in the Report of 

 the Hawaiian Board of Agriculture and Forestry for the biennial 

 period ending December 31, 1914, the writers gave a large number of 

 percentages of parasitism obtained during their biological work. The 

 present paper records similar data obtained during the year 1915. 



As shown by the reports of the Hawaiian Board of Agriculture 

 and Forestry, the South African Opius humilis and the Australian 

 Diachasma tryoni were introduced by Dr. Silvestri as a result of the 

 first parasite expedition to West Africa, while Tetrastichus giffardi 

 and Diachasma fiillawayi are the results of the Fullaway-Bridwell 

 Expedition to West Africa. For a full account of these expeditions 

 see the Report for the year 1913-1914, and Bulletin No. 3 of the Ha- 

 waiian Board of Agriculture and Forestry. 



For the information of the reader it should be stated that a few 

 specimens of 0. humilis and D. tryoni were liberated in the Kona 

 coffee district on June 13, 1913, but in Honolulu neither parasite was 

 liberated until December 1913, when colonies of 0. humilis were lib- 

 erated. No D. tryoni were liberated in Honolulu until early in 1915. 

 Between October 27 and December 31, 1914, Mr. D. T. Fullaway re- 

 ports having liberated 14,450 specimens of T. giffardi on the Island 

 of Oahu and 2,800 in the Kona and Hilo districts of the Island of 

 Hawaii. Of D. fullawayi during the same period but thirty-five 

 specimens were liberated on the windward side of the Island of Oahu, 

 and 195 specimens in the Kona district. Island of Hawaii. Although 

 many more liberations were made during 1915, it is evident that the 

 percentages of parasitism of D. fidlawayi and T. giffardi recorded in 

 Tables I, II and III represent the establishment and control exerted 

 by these parasites during the first year after their liberation, both in 

 Honolulu, and in the Kona district of the Island of Hawaii; while 

 those of 0. humilis and D. tryoni represent the control exerted by 

 these two parasites during their second year after establishment in the 



