aji Insect destructive to Oranges. 481 



time of the worthless oranges, which are punctured in the above- 

 mentioned manner, would serve at least to diminish the evil, if not entirely 

 to eradicate it.* 



I shall now describe more particularly the appearance of an infected 

 orange, which may be at once known by a greater or less portion of its 

 rind being withered, and shewing evident symptoms of decay, in having 

 lost its firm consistency and texture, and in having changed the usual 

 brilliancy of its colour for an opaque and dull olive yellow. The size of 

 this withered and discoloured spot must of course, in a great measure, de- 

 pend on the havoc committed in the orange by the concealed insect. 

 While, however, the fly is in its larva state, this spot appears to vary from 

 a space that might be covered with a sixpence, to one that might be co- 

 vered with half-a-crown. In the centre we may perceive a small white 

 orifice, which is the puncture of the parent insect, and which in general 

 may be distinguished with ease from the orifice made by the larva previ- 

 ous to metam.orphosis by a certain whiteness of the sides, which appears 

 to result from some mould or other vegetable of that nature. 



On opening such a fruit as has just been described, we discover the 

 whole space from the discoloured spot to the core to be in a state of per- 

 fect decay, the juice having disappeared, and the fibres being completely 

 decomposed, and covered in a greater or less degree with that blue and 

 white mould which is usual in decayed oranges. The rest of the orange 

 is generally entire, but so desiccated as most imperfectly to represent that 

 pulpy substance, which in a good St. Michaels' fruit is so replete with 

 juice. It is reveUing in the decayed part of the orange that we find the 

 larva of our fly, which, when of suflScient maturity to emerge from it, 

 undergoes its coarctate metamorphosis outside the fruit. 



I became acquainted with this insect in its various states, in 1822, when 

 I made my drawings and dissections of it. One of these drawings, which 

 :s that of the male in its imago state, highly magnified, I herewith send 

 you to accompany the publication of this notice. At that time I found 

 that I could not proceed on any generalizing anatomical principle with the 



* I ought, however, to observe, that I have seen the perfect fly on a heap 

 of oranges in the market-place of Funchal, in the Island of Madeira, and also 

 in St. Jago, one of the Capeverds. I am informed, moreover, that a maggot 

 infests oranges in the West Indies, but I have not myself yet seen it. 



Vol. IV. K K 



