Pkoceedings, 1921. 119 



tract of range land the farmers co-operate, and by meeting on a certain 

 day they all help in mixing and spreading the bait. Boilers are used on 

 such occasions to mix the liquids in ; the hot water more readily mixing 

 with the molasses and bringing out the full flavour from the chopped-up 

 lemon-rinds. While the liquids are being prepared wagon-covers, sheets, 

 etc.. are spread on the ground and the bran and Paris green mixed ready 

 for the liquids to be added. Some mixing is also done in wagon-boxes in 

 the field. Towards evening, when all the mixing has been done and the 

 poison bait put into the wagons, the mixture is spread broadcast by men- 

 standing in the back of the wagons. The wagons are lined up so that there 

 would be no ground left uncovered and driven forward in line over the 

 areas previously mapped out, spreading the bait at the same time. Men 

 en horseback are employed to keep the wagons in line, and others to lead 

 them through the places which had previously been located as the most 

 frequented by the locusts. 



As night came on the bait kept moist, so that on the next day there 

 were very few locusts throughout the region who did not find and devour a 

 few flakes of bran. In this way a very efficient control was maintained and 

 the cost sustained by the farmers was not great. The ingredients are 

 usually bought in quantity and the results amply justify the time or money 

 spent. The cost of this Kansas mixture as used in Canada in 191 5 and 

 1916 was found to be 21 cents per acre, including all labour, so that it will 

 be seen that the expense is not great for the results obtained. It has been 

 found that from 4 to 5 lb. of this mixture to the acre is sufficient, provided 

 it is properly prepared and distributed as evenly as possible over the ground. 

 A larger quantity per acre or a larger percentage of Paris green will 

 undoubtedly kill more locusts, but the cost is greater, and 4 to 5 lb. properly 

 applied has given a thoroughly satisfactory control. Two applications of 

 this standard formula would certainly give better results than one applica- 

 tion of a stronger mixture. As a rule there is no need for more than 

 one or two applications of bran mixture, but cases have been recorded 

 in the United States where a big swarm of locusts on the range lands, having 

 reduced the food on the ranges, move down to the crops in the valleys. In 

 such instances it is necessary to keep a constant supply of the bait spread in 

 a narrow strip along the edge of the range lands adjoining the cultivated 

 crops in the valley. In this way all locusts crossing this control belt would 

 come in contact with the bait and the majority would eat some of it. In 

 spreading poisoned bait in a field it is not necessary to be very particular 

 to cover every yard of ground, as the locusts, being very active insects, with 

 a good sense of smell, will find it. They will come from 15 to 20 yards to 

 bait placed in heaps, which shows that they can detect its presence from 

 some way off. The effect of poison on the locusts is not observed at once, 

 and it is usually from three to four days after they have eaten it before they 

 die. This is with the Kansas formula as given; a stronger percentage of 

 Paris green will act quicker, but is unnecessary, as the locusts eat little, 

 if any at all, once they have the poison in their systems. 



