MOTH-BORER. 129 



Remedies. There are several things which may be done to check the 

 increase of the moth- borer, but they will only be fully effective if they are 

 all done, so that the pest is checked all the year round. No remedy will 

 entirely kill out the insect, and if it is checked only at one season it will 

 increase again during- the rest of the year. In every place where the 

 moth-borer is found, it should be attacked in cane, maize and sorghum, if 

 all these are grown. 



(1) Cut out all the young shoots of cane that are seen to wither. 

 When the moth-borer attacks the shoots, the centre leaves wither and 

 dry up ; if these shoots are cut out with a knife, low down just below the 

 soil, they can be taken away with the caterpillar or chrysalis inside. 



This does no harm to the cane as the shoots would not live in any case 

 and other young shoots will grow again just as well. These dead shoots 

 should then be piled in a heap and burnt. They must not be left on the 

 ground as the caterpillar will come out as a moth in due time and lay eggs 

 in the field again. The object of cutting out the cane is to check the 

 borer at the beginning. 



(2) Sow maize or sorghum among the canes when the cane is planted. 

 This will come up quickly and the moths may lay eggs in the maize or 

 sorghum and the caterpillars will not attack the cane. The plants of maize 

 or sorghum may then be removed with the borers in them, say in six 

 weeks or two months after sowing. These plants must be removed from 

 the field and if they have many insects must be destroyed. In any case 

 the insects must not be allowed to come out as moths and breed. 



(3) Cut out all young sorghum or maize shoots that are attacked and 

 burn them. This is just the same as the first remedy and has the same 

 effect. It can only be done in the young plants because it is only then 

 that the shoots which are attacked can be seen by the withered leaves. 

 When the plants get bigger, the borer cannot be cut out, because that 

 would kill the whole plant. 



(4) Destroy the stubble of the sorghum or maize plants after the 

 crop is reaped. During the winter the caterpillars live in the stumps of 

 the sorghum left standing in the field. From these caterpillars come the 

 brood that attacks the crops after the winter. Great numbers can be 

 destroyed in the stubble so that this is the most important remedy ; the 

 moth-borer will probably be more thoroughly checked by this practice 

 than by any other remedy. 



J2nemies.-^-As the caterpillar lives inside the plant few insects can 

 attack it, so tjiat many enemies that feed upon most caterpillars are power- 

 less. Three insects are known which lay eggs in the body of the cater- 

 pillars (figs. .151^ 322) ; these eggs hatch cjuickly to maggots which live 



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