PESTS OF -RTJlT. 



passage fills up behind them and a few days after the maggots have 

 reached the inner pulp, the hole in the rind closes completely up. When 

 several maggots are contained in a single fruit, it gets stunted and 

 dies ; if the number is only three or four, the fruit decays only if the 

 maggots bore out through the rind. 



When full grown the maggot is about half an inch long ; it pupates 

 in the fruit or, if the fruit is much eaten or decayed, in the soil. Pupal 

 life lasts for 13 to 18 days, the whole life history occupying one month. 

 There are two broods in the melon crop, the first a small one, the 

 second very large. 



This account of the Melon Fly is typical of the whole group, with 

 small distinctions. As a rule eggs are laid in the fruit, not on the rind. 

 The critical point in the attack is the first brood ; if the first flies can 

 be prevented from laying eggs or the first larvae destroyed, the immense 

 second brood is checked. 



These flies have been very carefully studied in other parts of the 

 world where they are very serious pests. We have, therefore, the experi- 

 ence of other countries to guide us in our attempts to check the pest. 

 Actually two measures only can be advised which are adopted else- 

 where. It may be taken for granted that once the fly has been allowed 

 to lay eggs, the infected fruits are doomed. No possible treatment can 

 destroy the maggots in the fruits. Also there is no method of destroying 

 the flies on a large scale and so killing them before the fruits ripen. 

 It is possible to prevent the flies from laying eggs by the use of 

 netting. The flies only lay eggs on ripening fruits, and in South 

 Africa the fruit trees liable to attack are covered in cheap mosquito 

 netting of a fine enough mesh to keep them out. This simple remedy 

 is practicable where the value of the crop to be saved exceeds the cost of 

 the netting. 



In addition, it is clearly wise to check the increase of the flies them- 

 selves in the fruits. The early ripening fruits are naturally first attacked 

 and from them comes the large second brood that attacks the main crop. 

 Every fruit that falls from the tree, and every fruit that is found 

 to be infested, should be destroyed to prevent the flies emerging and 

 multiplying. 



At the present time an effort is being made by entomologists 

 abroad to utilise the natural enemies of these flies and introduce 

 them to places where they do not at present exist. Up to the present 

 there appears to be no reason to anticipate much practical result 

 from this method until a far greater amount of investigation has 

 been made. 



