CERATITIS CITRIPEBDA. 55 



Having been specially requested to offer some sugges- 

 tions as to means of lessening this attack I endeavour 

 to do so, but at the same time must beg my readers to 

 bear in mind that, as I have not technical knowledge of 

 the S. African methods of fruit growing, I am only able 

 to suggest on the general principles of prevention which 

 are applicable everywhere. 



It is plain that a large proportion of the maggots 

 causing the attack come to maturity very rapidly in the 

 ripe fruit. If this infested fruit can be distinguished 

 from the sound, might not some proportion of it be 

 hand-picked, and thus much future infestation be got 

 rid of ? Fruit need not be dead ripe for many household 

 purposes, and with a little management much of the 

 infested fruit might be utilized. No information is given 

 as to whether the infested fruit matures sooner and falls 

 more easily than the sound : if it did so, gentle shaking 

 of the trees, and turning sheep or pigs on in case of 

 orchard infestation, would clear off the fruit and all the 

 contained pests immediately. But investigation appears 

 to be needed as to whether this " Orange " or so-called 

 " Trypeta " Fly is double-brooded. Mention is made 

 that the flies hybernate in small numbers. Is it not 

 possible, as with very many other insect attacks, that 

 the second brood may differ in habits, and that the 

 maggots of this may hybernate in maggot or chrysalis 

 state just below the surface of the earth, and come out 

 in fly condition in what is the following spring of the 

 S. African season ? 



It might be found out very easily whether the maggots 

 drop to the ground, by laying cloths smeared with any 

 sticky material which would prevent them straying away 

 beneath a few of the infested trees, and this I think 

 would be particularly desirable with regard to apple 

 Trypeta attack. It might possibly prove on investigation 

 that some at least of this was originated by importation 

 of the American Trypeta pomonella, which, though of a 

 different genus, is of the same family, and certainly 

 similar in some of its habits. 



