146 



their laud will produce, they must adopt remedies to protect their 

 crop from the ravages of pests which want the sugar as much as they 

 do. No measures are likely to be satisfactory which are not speoially 

 suited to the habits of the insect ; it is necessary to clearly understand 

 how, when and where the cane is attacked, and above all to find out at 

 what time and in what way the pest is most open to attack. If the 

 life history ani habits of the moth-borer were fully understood, reme- 

 dies would sugge.-t themselves and could be intelligently and success- 

 fully applied. 



LIFE HISTORY OF MOTH-BORER. 



The life of the moth-borer falls into four periods ; (I) the egg ; (2) 

 the caterpillar or "worm"; (3) the chrysalis ; (4) the moth. The in- 

 jury to the sugar cane is done entirely by the caterpillar ; the chrj^salis 

 is simpty the resting stage, while the moths live solely for the pur- 

 pose of laying eggs . 



Eggs. — The eggs should be familiar to 

 anyone who sees young canes. They are 

 laid on the leaves, usually on the midrib, 

 and on young plants can be found with 

 great ease They are flat, oval in outline, 

 laid in patches, one egg partly overlapping 

 another like the tiles of a house A single 

 ^- across, about the siae of this 

 o. " There may be as many as 57 

 in OLe egg-patch or as few as six, but the 

 average number in each of 80 lots counted 

 was found to be about 20. A patch of eggs 

 is readd}^ seen on a leaf owing to its colour- 

 ing fcnd peculiar form. Both sides of the 

 leaf should be examined and the whole length of the leaf from the tip 

 downwards. The colour of the eggs when freshly laid is a creamy- 

 white, but as time goes on they become orange and when the cater- 

 pillar is ready to come out they are orange-brown with a black spot. 

 The caterpillar is hatched in 5 or 6 days and the empty egg cases 

 are white. 



Moth borer eggs are attacked by a parasite that does good service by 

 destroying the caterpillar before it can come out of the egg. Eggs 

 containing parasites are black, and are thus distinguished from the 

 ordinary eggs out of which caterpillars come. 



If these black eggs are kept, numbers of minute flying insects will 

 emerge. Two kinds of eggs can thus be found on the cine plants : 

 First, the ordinary eggs of the moth borer, which will pass through the 

 changes of colour describ3d above, and from which borer caterpillars 

 come : Second, the eggs of the moth borer that contain parasites, which 

 eat the contents of the eggs, and prevent the formation of a borer 

 cat'^rpillar ; the latter are black, and remain so till after the flies have 

 come out. Careful examination of the eggs will show whether they 

 contain caterpillars or parasites, the orange or yellow colour distin- 

 guishing those eggs without paiasites. It is only when the caterpillar 



egg IS ^% m. 

 letter " 



Fart of a leaf 

 cane plant, with a 

 Moth- borer eggs, 

 size. 



of a young 

 patch of 

 Natural 



