92 



BULLETIN 536, U. S. DEPARTMENT OF AGRICULTURE. 



Table XXIV. — Longevity records of Opius humilis and Diachasma tryoni ' at Hono- 

 lulu from November, 1914, to March, 1915. 



Age on 

 date of 

 observa- 

 tion. 



Number of specimens 

 dead. 



Age on 

 date of 

 observa- 

 tion. 



Number of specimens 

 deaa. 



0. humilis. 



D. tryoni. 



O. humilis. 



D. tryoni. 



3 



S 



d 



9 



cf 



9 



cf 



9 



24 

 25 

 26 



28 

 29 

 30 

 32 



34 

 35 

 37 

 38 

 43 

 45 

 46 

 47 

 49 

 50 

 51 

 52 

 53 

 54 

 55 

 56 

 57 

 58 

 59 

 60 

 62 

 63 

 65 

 66 



1 



1 







67 



68 



69 



70 



71 



73 



74 



75 



76 



79 



80 



81 



82 



S3 



84 



85 



87 



88 



91 



94 



95 



98 



100 



101 



103 



104 



105 



107 



111 



124 



125 



1 



2 

 2 



1 



1 

 1 



1 



2 



2 

 1 



2 

 1 

 2 

 1 

 1 

 2 

 3 

 2 

 2 

 4 

 1 







1 



1 

 2 











1 

 3 

 1 

 3 

 4 

 1 

 1 

 2 

 1 

 3 

 7 

 1 

 2 

 3 

 1 

 1 

 1 

 2 

 1 



2 

















2 

 3 









1 





l 







3 

 5 













1 











1 



7 

 3 



6 



7 



3 



1 



6 " 



3 



2 



1 



8 



2 



1 

 1 



3 

 1 



4 



3 

 1 

 7 

 1 

 4 

 3 

 2 

 2 

 1 

 3 

 1 

 1 

 1 

 2 

 2 

 1 

 2 

 2 

 2 

























1 



1 

 1 



1 



1 

























1 



2 











5 

 1 



1 



3 



8 

 5 

 4 

 6 

 3 

 8 

 3 



































1 

 1 













1 







1 No record was kept of adults dying during first 23 days after emergence. 



Fourteen females of Opius Jiumilis lived to be over 100 days old; 

 the last two being 125 days old. One female Diachasma tryoni 

 lived to be 125 days old, although this species appears to be more 

 frail and less able to survive captivity. Unfortunately no record 

 was kept of the number of adults of either species dying during 

 the first 23 days after emergence. 



Proportion of sexes. — A count of the sexes of 25 lots of Opius 

 Jiumilis reared from C. capitata developing in various fruits during 

 September and October, 1914, showed 145 specimens to be females, 

 and 141 males. 



Mating. — Mating may occur immediately after emergence in all 

 three species, Opius humilis, Diachasma tryoni, and D. fullawayi. 

 Virgin females may deposit parthenogenetic eggs which, however, 

 develop males only. 



Length of life cycle. — There are no satisfactory data on the length 

 of the life cycle under varying climatic conditions. The statement 

 of Silvestri that the egg, larva, and pupa stages may be completed 

 in from 14 to 16 days is a safe estimate for the minimum length 

 required for the development of these stages. Specimens of 0. 

 humilis, developing from eggs deposited August 21 to 22, 1914, 



