Nov. 25. 1918 Biology of Fruit-Fly Parasites in Hawaii 453 



on October 8, 1917, 7.3 per cent were parasitized by T. giffardianus. 

 Parasitism by T. giffardianus of larv^aefrom these fruits, and other varieties 

 picked from the ground on the same dates, was not appreciably higher 

 than that just cited. . The individuals reared from larvae coming from 

 kamani fruits picked from the trees indicate that the females may fly 

 well up above the groun'd, for the lowest fruits of the kamani are usually 

 from 10 to 12 feet above the ground. It is a high, wide-spreading tree. 



Although the female oviposits into any portion of the host larva within 

 reach, the majority of the eggs are placed in the posterior half of the 

 body. This is because the larva buries its head into pulp or juice almost 

 as soon as a female touches it, and, in her attempts to cling to the larva 

 and insert the ovipositor, the attachment is not ordinarily made until 

 she has been drawn back toward the posterior end. The female may 

 oviposit into a larva without being actually in contact with it. This 

 occurs when the ovipositor is forced through thin layers of pulp under 

 which the female may detect the presence of a larva. The larva must be 

 close to the female, however. A distinct, brownish, oval scar remains 

 on the larva at the point at which the ovipositor has been inserted. This 

 character is more clearly discernible after the larva has formed into a 

 puparium. 



The maximum number of eggs deposited by a given female in confine- 

 meat was 104 (see Table VI). The greater number of eggs is deposited 

 during the first five or six days after the female emerges. They are 

 usually deposited in large lots at intervals 24 to 48 hours apart, rather 

 than in small numbers frequently. The greatest number of eggs de- 

 posited by a given female over a period of 24 hours was 62. No oviposit- 

 ing female has been kept alive longer than 12 days. The great prolific- 

 ness of this species is here seen from its habit of oviposition and in the 

 proportion of sexes above mentioned. With an average life cycle of ■ 

 about 25 days, a deposition of from 90 to 100 eggs within the first five or 

 six days of life, and the resulting progeny 75 per cent female, the multi- 

 plication is seen to be very rapid. Fruit-fly larvae in the second instar 

 may be successfully parasitized. 



Adults fed with honey and water and confined in glass tubes held in 

 partial darkness have been kept alive from two to three months without 

 difficulty, provided no opportunity is given for oviposition. Of 274 

 adults emerging on September 3, 1917, one male lived for 6i days and 

 one female for 69 days. Most of the males died between the ages of 30 

 and 50 days, while the majority of the females died between the ages of 

 40 and 60 days. Of 267 adults emerging on December 19, 191 7, one 

 male lived for 58 days and one female for 102 days. Nine of the females 

 lived over 90 days. This long life was due to the mild temperatures of 

 December, January, and February. Without food this parasite usually 

 dies within 46 hours, although one individual has been held alive for 55 

 hours. 



