54 



THE CODLIN MOTH. 



By His Honor Mr. Justice Dobson. 



[Bead 12th May, 1879.] 



Some time ago I called the attention of the Society to 

 the devastation created by the larvae of the codlin moth in 

 the orchards in the Northern parts of the Colony. It has 

 appeared in the orchards in the vicinity of Hobart Town during 

 the last year to an extent that must alarm all those con- 

 cerned in apple growing, and this is an extensive industry 

 representing an export trade of not less than £40,000 a year. 

 On the former occasion I pointed out something of the history and 

 habits of the moth and its larv£e, but the all important question 

 now is, how it can best be destroyed 1 After the moth has deposited 

 an egg in the eye of the young apple, and it seldom deposits more 

 than one egg in an apple, the egg hatches and the young creature 

 eats its way through the tender skin of the apple at its eye, into 

 the substance. The orchardist is not aware of its presence till 

 he sees a dark spot on his apple, and then a hole from which the 

 creature expels small grains of excrementitious matter which cover 

 the orifice of the hole. It feeds on the pulp and attacks the pips, 

 the most vital part of the apple, which then falls and the creature 

 escapes through the orifice which it has made. Its exit is rapid, 

 and many apples may be examined in the morning, which have 

 fallen during the night, before one is found in which a grub remains. 

 The apples from which it has escaped, may be recognised by the 

 orifice of the hole being cleared from the little brown grains which 

 close it, the grub having cleared them away in coming out of the 

 , hole. The grub having thus passed through the luxurious period 

 of its existence has now to consider the process of reproduction. 

 It makes usually for the stem of the tree, and ascends till it finds 

 a crevice in the bark ; it there eats its way between the outer and 

 inner bark, and makes a smooth and rounded resting-place for 

 itself. There it spends its time in lining the hole with a Aveb 

 that it spins. It then become a chrysalis, and waits for the 

 warmth of approaching summer, when the young moth comes forth, 

 to repeat the process. The insect cannot be assailed when in the 

 apple. Its destruction can, therefore, only be accomplished either 

 in its moth state, or after it has left the apple. It is a night moth, 

 and in England and America attacks the apples in June. Here we 

 may assume that it does so probably in November, or early in 

 December. The only known mode by which the moth can be 

 destroyed is by lighting fires in the orchard, and in America the 

 cuttings of the orchard are preserved to light fires for the purpose 



