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showed numerous scars, iiulicating attempts at oviposition, when 

 no injury to the seed mass or the flesh occurred to indicate the 

 feeding of the larvae. On the other hand, fruits were noticed, in 

 which fully grown larvae were found dead. This is explained 

 as being the result of an attack on fruits which were too young. 

 The contact with the juice of the unripe fruit is quickly fatal to 

 the larvae. It is evident that the fruit was too young when at- 

 tacked, and that the maggots became fully grown and attempted 

 to penetrate into the flesh before it was sufficiently ripened, and 

 they were killed by contact with the juice. In the ripe fruit the 

 flesh is softer, and the gummy juice is no longer exuded. 



Pupal period. The larvae when full-grow^n usuallv leave the 

 fruit and fall to the ground, where they pupate, under some bit 

 of rock or buried in the soil at a depth of one or two inches. 



The length of the pupal period is given as seventeen to twenty - 

 one days in Porto Rico, and from thirty to forty-two days in 

 Florida. The latter figures were obtained as the result of ol)ser- 

 vations in the cool season of the year. 



Habits of the adult and oviposition. The adults of this species 

 appear only for a short time just before sunset. A female fly was 

 observed to alight on a well developed but unripe fruit. After 

 walking about a little she inserted the ovipositor its full length 

 into the fruit. As soon as the rind was punctured, the milky 

 juice which the unri])e fruit exudes whenever injured welled forth 

 and began to trickle down over the surface. It is evident that the 

 female fly endeavors to thrust her ovipositor through the flesh to 

 deposit the eggs in the central seed cavity, and that it is only 

 in those varieties with the thinner-fleshed fruit that this is suc- 

 cessfully accomplished. The larvae are always found in the seed 

 mass, except when they are full-grown and the fruit is ripe, when 

 they penetrate into the flesh with the object of working theii way 

 to the outside in order to get to the ground and pupate. 



Food plants. X'p to the present time no other fruit than the 

 papaw has been recorded as being attacked by this insect, and 

 all attempts to introduce the larvae to feed on other fruits have, 

 so far, failed. 



Rapid increase of the fruit fly. During the last two years the 

 papaw fruit fly has ra])idly increased in abundance, and has ex- 

 tended its range so as to threaten seriously the future develo])- 

 nient of the ])a])aw industry in Morida. This is largely a result 

 of the increased cultivation of the papaw in the southern part of 

 the State. Some varieties of Philippine stock producing large 

 fruits are apparently free from attack. 



Control. It has been pointed out that fruit with very thick 

 meat escapes infestation. While the papaw fruit fly attcnijits to 

 oviposit on such fruil, the thickness of the meat prevents the liji 

 of the ovipositor fnim reaching the seed cavity, and in the nuat 

 itself the larvae cannot h\r. It was further foinid that in some 



