USE OF POISONS AGAINST THE GRASSHOPPER 33 



of deep ploughing, even if the burying is accompanied by 

 an inversion of the egg-masses. Freshly-hatched nymphs 

 with burrowing powers and with powers of endurance such 

 as those exhibited by the Rice Grasshopper would certain- 

 ly be able to make their way to the surface, even if buried 

 at a depth greater than is at all practicable with an 

 improved plough. 



THE USE OF SPRAYS AND POISONED BAIT AGAINST 

 THE RICE GRASSHOPPER. 



The use of poison for combating grasshopper pests 

 has been frequently tried and, at times, with very marked 

 success. Perhaps the most signal success in this direc- 

 tion has been achieved against migratory grasshoppers 

 (so-called locusts) in South Africa, where, yearly, thoroughly 

 organised campaigns directed by a central committee save 

 immense sums of money to the farmers. The mixture 

 there used is one of arsenic or arsenite of soda (strong 

 poisons) with sugar or molasses and water. The usual 

 strength used is 1 lb. of arsenite of soda and 2 lbs. of raw sugar 

 or molasses to 1 6 gallons of water. This is commonly spray- 

 ed upon the grass in front of the advancing swarms of grass- 

 hoppers and has proved most efficient. Lefroy, in his 

 work in connection with the Bombay locust, investigated 

 the effect of insecticides (lead arsenate, jaggory and water; 

 sodium arsenite, jaggory and water; white arsenic with 

 caustic soda, jaggory and water) upon that insect. He 

 dipped fodder in the poisonous mixtures and fed it to 

 locusts in captivity. The weaker solution of lead arsenate 

 lib., jaggory 5 lbs., and water 100 gallons, he found to kill 

 the locusts, while they refused to touch the other and 

 stronger mixtures. Lefroy also tried contact poisons such 

 as kerosene emulsion, and McDougal's sheep dip sprayed 

 on to captive locusts with apparently satisfactory results. 

 He does not appear to have tried any of these measures 

 to any considerable extent in the field. They were, 

 however, tried in a practical way in the Central Provinces 

 during the campaign against the Bombay locust and 

 were not found satisfactory {vide Standen's Report in 

 Lefroy's Memoir on the Bombay Locust, Appendix B, 

 pages 85-86). 



R. G. D 



