No. 1. ] Fruit Trees. 73 



■colour and not brown. I smothered them all, as I was convinced the 

 intruder was the maggot of a fly which had been deposited on the fruit 

 when it had come to maturity and not the one of the codlin moth, 

 while the fruit was only a blossom. 



•' I am most grateful to you for your offer of identifying the fly. It 

 was not known to the late Miss Ormerod. I am sending yo u by to-day's 

 post a tin box of apples full of maggots and another small box full of 

 male and female flies. 



" I have killed two or three different kinds, but the one which does 

 the mischief is the brown two-winged fly. 



"The question now is, how is he to be destroyed and not driven 

 away ?" 



On the nth October, Colonel Rennick wrote: — 



" I have sent you yesterday a small box containing two applesj 

 which had been tainted by the fly. One, a Cellini, the other a 

 Blenheim orange, a sweet and an acid one, which made no difference 

 to the fly. You will find at the least a dozen fat maggots in them 

 by the time the box reaches Calcutta. The maggots jump almost a 

 foot when full grown. They are brought to life as small maggots and 

 not as eggs, — so different from the home flies. 



"In another box you will find two match boxes. One contains a 

 ■lot of flies, both male and female, 1 have caught and killed with Cya- 

 nide of Potassium, and the other a lot of cocoons formed by the 

 maggots on leaving the fruit to pupate in the soil. 



" From last year's observations I found that the maggots, the stout 

 and jumpy ones at any rate, took 13 to 14 days to come out as a fly. 

 So 1 had all the fruit cut up and broken, thrown into long shallow 

 trenches on the 26th September. On the gth and 10th October, when 

 1 moved the rotten fruit, I found most of the maggots had left the fruit 

 and gone into the soil and I had no difficulty in getting out lots of these 

 cocoons for experimental purposes. The remainder I hope to have 

 destroyed by flooding the trenches with a solution of sulphate of copper, 

 soft soap and kerosene oil made up into a kind of concentrated emul- 

 sion. I find this mixture kills the maggots. I have hatched a lot 

 of the young flies which I hope to send you in a day or two. I have 

 built a breeding room about a cubic yard for propagating these flies 

 and to ascertain their habits and their natural age. It is fitted 

 with wire gauze ventilators and three large pane glasses to observe what 

 goes on daily, hourly in the chamber. I have caught a fly to-day with 

 a lot of live maggots in it, and I despair of eradicating the pest. I do 

 not want to drive it away; but to entirely destroy it. Three flies I 

 killed a short month ago, the first contained 82 live maggots, the 

 second 64, and the third 67 maggots ! ! They are loathsome." 



