S2 SOME SOUTH INDIAN INSECTS. ETC. [CHAP. XI. 



AGRICULTURAL METHODS. 



On the sound principle that "prevention is better than cure " 

 agricultural methods aim rather at checking any undue increase of 

 crop-pests than at actual control after they have attained destructive 

 numbers. Such methods are therefore extremely important and 

 should invariably form part of the regular routine of the agricultu- 

 rist. They include such means as clean cultivation, the proper 

 rotation of crops, the growing of mixed crops, ploughing, changing 

 the time of planting, the use of poultry and encouragemeni ol 

 insectivorous birds, the stimulation of plant growth by means 

 of manures, irrigation and draining, the selection of resistant 

 varieties of crops, and the use of attacked crops as fodder. 



Clean cultivation, by which is meant the careful removal of 

 weeds and wild plants from the fields and their adjacent areas 

 such as bunds and the removal of all crop-remnants after harvest, 

 is by itself one of the most potent weapons in the cultivators 

 armoury in his ceaseless war against the ravagers of his crops. 

 Not only the field itself should be carefully weeded before the crop 

 is sown and while it is growing but the bunds and all similar 

 adjacent areas should also be kept clear as far as possible. Many 

 insect-pests feed on wild plants and. having eaten up these or find- 

 ing a succulent crop alongside and more to their taste, pass into 

 the cultivator's fields and take their toll of the produce; Kumblihulas 

 are familiar examples of this and the Ricebug (Leptocorisa) also 

 commonly lives on wild grasses on the edges of paddy-fields until 

 the paddy begins to come into ear when that is invaded and 

 attacked. Proper attention should therefore be paid to weeding 

 not only in the field itself but on the bunds around it and in any 

 contiguous uncultivated area. A belt of open ground forms in itself 

 an excellent defence against invasion from outside by pests such 

 as caterpillars which are exposed to attack by various predaceous 

 enemies (birds, ants) before they can obtain access to the cultivated 

 area. 



\ verj o >mmon practice in cultivation is to leave crop remnants 

 on the ground and this is a measure which is particularly dangerous 

 in the case of cereals on account of the stem-boring insects which 

 live on in the stubble and infect the next crop in the same or neigh- 

 bouring fields. Cholam, ragi, paddy, wheat, and similar cereals 

 are all affected by various stem-borers and it is a common sight to 

 see a field in stubble from an old crop whilst alongside is a field 

 growing a new crop oi the same kind ; needless to say, all the pests 

 rallied ovej in t he stubble of the old crop simply move across and 

 attack the new one. Leaving a field in stubble often also encourages 

 the increase of Termites which are thereafter hard put to it for 



