184 TFIE KNTOMOLOGIST. 



which have been, or are about to be, brought under con- 

 sideration ; these are the Aurantiaceee or citronworts, in- 

 cUiding the orange, lemon, citron or lime, and shaddock, all 

 of them truly exotic as regards Britain ; and the Pomaceae or 

 appleworts, including the apple, pear, quince, medlar, service, 

 and mountain-ash, all of which in their natural condition, 

 appear to be truly indigenous. Mr. MacLeay was evidently 

 only acquainted with the ravages committed by the fly on 

 fruit of the first of these orders ; and even here he seems to 

 have been sadly misinformed, for he attributes to this fly a 

 much greater power of destruction than it really possesses. 

 After stating the enormous loss incurred by the decay of 

 oranges in transit from the Azores, &c., an estimate of loss 

 in which the orange-merchants of to-day by no means con- 

 cur, he goes on to say : — " Now, the decay of St. Michael 

 oranges, which form the great bulk of those brought to the 

 London market, is, towards the end of their season, namely, 

 during the months of March, April and May, almost uni- 

 versally accompanied by the presence of the larva of a small 

 fly, which I shall show by observations made by a friend in the 

 Isle of France and by myself in London, to be the cause of 

 the evil. * * * As for the St. Michael oranges, towards 

 the end of the season whole chests are destroyed by this fly, 

 specimens of which are easily to be procured, as they may 

 be bred from the larvse which ai'e to be found in almost 

 every one of those damaged oranges which our barrow- 

 women display for sale in the month of May." This, how- 

 ever, is not shown ; and although it is quite certain that the 

 Ceratilis is often found in these decaying oranges, I am 

 informed by my friend Mr. Hanson, than whom there is no 

 higher authority, and whose scientific knowledge of the fly 

 is probably unequalled, that the chief causes of decay are, 

 first, gathering the fruit in wet and unsuitable weather; and, 

 secondly, injudicious packing, and consequent heating on 

 the voyage. 



Now as to the modus operandi employed by the parent 

 fly. Let us begin with the first statement of Latreille, who 

 ('Regne Animal,' vol. v. p. 534) informs us that "les colons 

 de rile de France ne peuvent presque pas, d'apres des 

 observations que ra'a communiquees M. Caltoire, obtenir des 

 citrons sains et en parfaitc maturite, a raison de I'exlreme 



