148 



The following table shows the length of each stage of the life his- 

 tory and where it is passed : — 



Stage. 



Duration. 



Where fouND. 



Egg 



6 days 



On the leaf 



Caterpillar 



35 days 



In the cane 



Chrysalis 



7 days 



In the cane 



Moth 



2 days 



Flying about 



Hence the maximum length of time required for one generation is 

 50 days : the whole life from the time of the laying of the eggs to the 

 death of the moth may, however, be only 42 days. 



When the life history of this insect is fully understood, it becomes 

 clear that there are two periods of its life when it is easily attacked : 

 (1) the eggs, which are laid openly on the leaves of the cane ; and (2) 

 the moths, which fly about. Any attempt to destroy the caterpillar 

 or chrysalis would involve the destruction of the infested cane, which 

 is practicable only in young canes which can be cutout, or very badly 

 diseased old ones which should be removed and burnt. 



REMEDIES. 



Collecting Eggs. — The simplest remedy is to collect the eggs and 

 burn them. The young canes on the whole estate s^hould be examined 

 once a week by boys, who must first of all be taught to recognise the 

 eggs on the young plants. They must clearly understand that the 

 black eggs are not to be touched, but are to be left on the canes. They 

 should go systematically down the rows of canes, carefully inspecting 

 every plant. They must examine both sides of every leaf, and on find- 

 ing a patch of either cream-coloured, orange, or orange and black eggi 

 the leaf should be cut oS below the patch of eggs and put in a bag. 

 Those patches of eggs that are wholly black and have no orange colour 

 must be left on the plant in order that the parasites may escape and 

 destroy more eggs. 



The eggs that ere cut ofi, should be brought in and immediately- 

 burned. 



If it is remembered that there are on the average nearly 20 eggs ia 

 a patch, the number of eggs that can thus be easily and cheaply des- 

 troyed is seen to be very consideiable. 



If this remedy were adopted as soon as the young cane commences io 

 show and continued as long as the cane is sufficiently small, there 

 would be no loss from *^ cut out" canes, and practically all the best 

 shoots would not then have to be destroyed, as at present. 

 . The recommendations recently made contained no reference to th» 

 black eggs : it was believed that a certain proportion of the black eggs 

 contained caterpillars and that it would be dangerous to leave these 



