112 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



least labor." Larger pans arc drawn or pushed by horses. The 

 oil is best used on the surface of water, from which the insects 

 are removed with a strainer, and any which hop out will die 

 after having come in contact with the oil. 



Destroying the Adults. The destruction of the winged insects 

 is an entirely hopeless task, for, though even large numbers 

 are caught, so many will remain that the damage done the 

 crops would be but very slightly diminished. One of the most 

 promising means for averting the swarms of winged migratory 

 locusts from alighting in the fields is by a dense smudge, in 

 which some foul-smelling substances are placed. Where strictly 

 attended, and with favorable winds, this has often proved highly 

 successful. To accomplish the best results farmers over an 

 extensive area should combine in its use. 



The South African Fungus. In 1900 Professor Morgan made a 

 test of a fungous disease which had been found to destroy large 

 numbers of grasshoppers in South Africa, to determine whether, 

 after starting it by artificial propagation, it would spread suffi- 

 ciently to destroy any considerable number of locusts. The 

 weather was favorable, rains being frequent. Early in August 

 it was found that " over the areas where the liquid infection 

 was spread diseased hoppers were abundant." " As many as 

 a dozen dead grasshoppers could be found upon a single plant, 

 and some upon nearly every weed on ditch-banks where grass- 

 hoppers were numerous. From the centres of infection great 

 areas had become inoculated, spreading even beyond the planta- 

 tions first infected." The property upon which it was placed 

 became thoroughly infected with the fungus. Strangely, though 

 many other species of grasshoppers were abundant, only the 

 differential locust was killed by it. Dr. Howard states that this 

 disease has also spread and done effective work in Colorado. 

 However, more recent experiments made by the writer in Texas 

 gave only negative results, and it is doubtful if any reliance can 

 be placed upon the artificial use of such fungous diseases for 

 locust control. 



Poisoning. A mash composed of bran, molasses, water, and 



