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commercial fruit-growing is just as difficult a problem as it is in Australia, 

 Africa, and South America. If the fruit has to become rotten with fruit- 

 fly maggots before parasites can be bred out, as it does in the guavas and 

 mangoes in Bangalore, whence these parasites were obtained, and where the 

 two species of fruit-fly, which the parasites infest, simply swarm through the 

 gardens and parks, they might just as well face the situation at once, and 

 niake their orchardists clear up and destroy infested fruit, as is being done 

 in all parts of the world at the present time. I was told in Perth, Western 

 Australia, "That we cannot get our orchardists to clean up their orchards, 

 so we must have parasites." 



All the evidence shows that while we may succeed with parasites to a 

 certain extent, and in some instances for scale insects, aphis, and even cut- 

 worms, and other lepidopterous larvae, yet, we may make up our minds that 

 under the present conditions of fruit-growing, we will have to resort to other 

 methods in reducing these two pests (codling moth and fruit-flies). The life 

 history of the true fruit-flies is just as peculiar in its way as that of the 

 codling moth. The female fruit-fly punctures the ripening fruit with a 

 wonderfully constructed ovipositor, at the same time depositing her eggs well 

 through the tough skin in the tissue beneath, and thus from the very first 

 moment the eggs are in a much more secure position than even those of the 

 codling moth. When the eggs hatch, the tiny moving maggot, enveloped in 

 the decomposing tissue of the fruit, is a very difficult host for the hymenop- 

 terous enemy on the outside to locate and stab while depositing its eggs in 

 the maggot, and as the maggots very sx>n work inwards they soon get beyond 

 the range of any parasite, especially whea deposited on such fruits as peaches 

 and oranges. 



Therefore, while in the maggot state, sheltered in the fruit upon the tree, 

 the fruit-fly maggot* are safe from most enemies. Then, in the ordinary 

 course of events the damaged fruit falls to the ground, and the maggots if 

 not full grown will remain in the decaying matter, and are still safe from 

 most enemies. The majority of them burrow into the ground underneath 

 the fallen fruit, and are still out of sight of their eaemies ; arid it is only 

 when the fallen fruit is disturbed bofore they have burrowed into the soil, 

 that the predaceous parasites have the chance of destroying them. Once 

 hidden in the ground they are comparatively safe from other insect enemies. 

 I consider, as do nearly all leading entomologists who have given the matter 

 of fruit-flies any attention, that it is very improbable that any internal 

 parasite will ever make any impression on this pest in the case of com- 

 mercial fruit, such as oranges, peaches, tfec. In all cases where parasites have 

 been bred, it has been from small, wild, or hard-fleshed fruits, and though 

 parasites may be quite numerous among some of the wild fruits, yet they 

 are not able to injure the larva? in large fruits. 



. The parasites in the Mexican Fruit Fly (Trypeta ludens) have never, as far 

 as I could learn, been bred from infested oranges, but from small fruit, like 

 the guava and native mango. The parasites in southern India are bred from 

 infested guavas, not from the thick-fleshed mango, in which the Indian Fruit 

 Fly (DacuH ferrugineus] is common; and among the many thousand Mediterra- 

 nean and Queensland Fruit Fly larvae and pupae we have handled and bred 

 from citrus fruits and peaches, we have only bred a few odd parasites. It is 

 one thing to demonstrate to the public the ability of a hymenopterous 

 parasite to deposit its eggs in the exposed larva? and pupa3 of codling moth 

 or fruit-fly ; but quite another for that same parasite to work or do any 



ood in the orchard. 



