CHAPTER XXVIII. 



INSECT PESTS 



The extent of the destruction to crops by various insect pests 

 in different countries is incalculable. According to a recent return 

 issued by the United States Agricultural Department, the direct and 

 indirect yearly losses caused by insects, in that country alone, 

 amount in the aggregate to the enormous total of over 700,000,000 

 dollars ( 140,000,000). The loss to tobacco crops is put down as 

 5,000,000, to cotton 30,000,000, and to apple crops 20,000,000 

 dollars. Though Ceylon possesses a large variety of insect life, it 

 has practically no insect-pest of an alarming nature as compared 

 with some other countries. Spasmodic outbreaks are, however, 

 liable to occur here as elsewhere, and it should always be remem- 

 bered that prevention is better than cure. There are many simple 

 precautions which are sufficiently obvious to anyone who practises 

 agriculture or horticulture intelligently, and the following hints, 

 briefly stated, may afford a guidance, being more or less adaptable 

 according to the nature of the crops or local circumstances. It 

 should not be forgotten that proper rotation of crops, a system of 

 intercrops, green-manuring, good cultivation or the application of 

 certain fertilisers (as kainit, nitrate of soda, etc.), all have a most 

 beneficial effect in the suppression of insect pests. In other 

 words, to maintain a vigorous condition of the plants or crops 

 cultivated is one of the most important safeguards against insect 

 pests or fungus diseases. Thus in reference to shot-hole borer 

 (perhaps the most troublesome pest of Tea in Ceylon), MR. GREEN, 

 late Government Entomologist, has stated : " I have repeatedly 

 observed that a vigorous condition of the plant results in a ten- 

 dency to choke out the insects. The mouth of the tunnel is 

 invaded by an ingrowth from the active cambial tissues. New 

 wood is then formed, covering up the old wound, and the plant 

 is able to carry on all its functions without interruption. The 

 object of the planter, therefore, should be to induce by proper 

 priming and cultivation such a vigorous condition that the damage 

 is automatically and continuously repaired." 



