43° 



Journal of Agricultural Research 



Vol. XX, No. 6 



the tip of the abdomen and finally comes to rest on the dorsal portion of 

 the pupa. This exuvium often adheres to the antennae of the male or 

 the ovipositor of the female for a short time after the adult has emerged 

 from the puparium of its host. The length of the pupa is 3.8 mm. 



When first formed it is pale 

 white, excepting the eyes, which 

 are a very dark reddish brown; 

 but within a few hours it begins 

 to acquire a yellowish tinge and 

 continues to assume the colora- 

 tions of the adult until ready to 

 emerge. 



The length of this stage varies 

 from four to eight days, even 

 though it is passed under the 

 same temperature and other con- 

 ditions. During the month of 

 July, 1 91 8, when the tempera- 

 ture ranged from 75 ° to 85 ° F., 

 90 parasitized puparia were 

 under observation. Adults of 

 Opius fletcheri emerged from 

 these puparia from 80 to 200 

 hours after pupation. Emer- 

 gence was taking place at fre- 

 quent intervals between these 

 two extremes but was most fre- 

 quent between 1 30 and 1 50 hours 

 after pupation. This would in- 

 dicate that the length of the 

 pupal stage in the majority of 

 cases was about six days. Be- 

 tween 80 and 100 hours after pu- 

 pation, 17 males emerged, but 

 it was between 100 and no hours 

 before the first two females 

 emerged. Thelastmaleemerged 

 after a period of from 1 70 to 1 80 

 hours, and the last two females 

 emerged between 190 and 200 hours after pupation. The pupal stage of 

 the male is usually about 24 hours shorter than that of the female. 



Fl<;. 12. — Opius fletcheri: Pupa, female. 

 3.8 mm. 



Length 



ADULT 



The following description of the adult by Silvestri is translated from 

 the Italian : 



