452 Journal of Agricultural Research voi. xv, no.8 



body and inserted into the body of the larva. In this operation the 

 body is reared up with the front plair of legs stretched at full length or 

 often drawn free from the larva. Only one or two seconds are required 

 for the insertion of the ovipositor. The barbs at the tips of the piercing 

 blades now hold the female securely to the larva. By the time the ovi- 

 positor is well inserted the female is standing straight up on the ovi- 

 positor and balancing, often on only one posterior leg and the ovipositor 

 or on the ovipositor alone, as shown in the photomicrographs (PI. 32) , after 

 which the female moves very little. The legs and wings are held perfectly 

 still, although the larva may frantically bore about in the pulp or escape 

 entirely from the fruit, in an endeavor to dislodge the parasite. To 

 all contortions the female parasite remains indifferent. When the larva 

 is held in position beneath a microscope a rapid transference of liquid 

 and eggs can be seen passing down the ovipositor. After the eggs are 

 inserted the ovipositor is withdrawn and sheathed in from 2 to 3 seconds. 

 The ovipositor is not removed until the female brings all feet down again 

 in touch with the larva or anything that may be conveniently in reach. 

 The female deposits an average of 8 eggs in a cluster, Avith each inser- 

 tion of the ovipositor. Between September 4 and 21, 191 6, 50 separate 

 ovipositions were under careful observation. The time elapsing for 

 each oviposition ranged from 9 to 60 seconds, with an average of 35.6 

 seconds. The number of eggs deposited at each oviposition ranged from 

 2 to 16 with an average of 8.6. This average is interesting as a labora- 

 tory experiment, for it was found that from 3,527 adults of T. gifjardianus 

 emerging from 412 puparia collected in the field during 1916 and 1917, 

 the average number emerging from these puparia was 8.6 per puparium. 

 It indicates that the parasite generally oviposits only once into the same 

 larva and that the larva is not again stung by another individual, in 

 the majority of cases. One curious point in the rearing of this species 

 from field material should be emphasized. In every case under actual 

 observation wherein a fly puparium produced several females of T. 

 gifjardianus, one male, and occasionally more than one, developed in the 

 same puparium with them. In other words, each time a mated female 

 places a cluster of 6 to 8 eggs or more in a larva, at least one of those 

 eggs is destined to produce a male, for usually i male and 6 or 7 females 

 ultimately emerge. 



It has been assumed generally that this parasite works mostly about 

 the ground. Certain evidence has been secured to show that it works a 

 great deal above ground also. Of 94 fruit-fly larvae emerging from 

 bestill fruits (Thevetia neriifolia) picked from trees on August 28, 191 7, 

 1 8. 1 per cent were parasitized by T. gifjardianus. Of 192 larvae secured 

 from the same host picked from the trees on August 16, 1917, 9.9 per 

 cent were parasitized by T. gifjardianus . Forty-five larvae from the same 

 kind of fruit picked from the trees on September 4, 191 7, produced 13.3 

 per cent T. gifjardianus . Of 533 fruits of the kamani picked from trees 



