28 INJURIOUS INSECTS OF 1903. 



ive if spread during hot, sunny weather, and it is further stated 

 that salt may be unnecessary, possibly, if the mixture is made 

 with fresh droppings. If used take two pounds salt for every 

 half barrel, dissolving it in water before adding. The Paris 

 Green should be mixed with water first and then added. This 

 mixture should be drawn to the field in a cart or half barrel, 

 and then broadcasted by means of a trowel or wooden paddle. 

 On June 24th Mr. Criddle wrote me as follows : 



AwEME, Manitoba, June 24, 1903. 

 Prof. F. L. Washburn, Agricultural Experiment Station, Minnesota. 



Dear Sir: I beg to thank you for copies of Press Bulletin No. 16 

 (on the Criddle Mixture), just to hand. Since Dr. Fletcher's Report of 

 1901 much improvement has been made in the mixture referred to. It 

 is now made as follows: One part, by measurement, of Paris Green to 

 120 parts horse droppings, preferably fresh, or about one pound of Paris 

 Green to half a coal oil barrel of barn droppings. One pound of salt should 

 be added when the droppings are not fresh. This mixture has taken 

 the place of all other remedies, here, after the locusts have once got too 

 large for the plow, and has so far proz'cd an unqualified success. It is with 

 great pleasure that I see you have taken it up. 



Thanking you again for the bulletin, I am. 



Yours truly, 



NORMAN CRIDDLE. 



It would seem from the above letter that the mixture can 

 be used with much less poison in proportion to the manure, 

 i. e., I part Paris Green may be added to 100 parts horse ma- 

 nure or even to a larger quantity with good results. Mr. Crid- 

 dle states that a good way to keep locusts on edge of field is to 

 sow a strip of rye around it. By this means the insects are 

 temporarily held where they can best be poisoned. The user 

 should bear in mind that arsenic in composition or by itself 

 is the toxic principle in Paris Green and is a slow poison. He 

 should not therefore expect the 'hoppers to die immediately. 



In looking up the ''grasshopper history" of Minnesota we 

 find that the first mention of grasshoppers (Rocky Mountain 

 Locusts) in Minnesota is in Neil's History of Minnesota, which 

 states that in 1818 and 1819 vast hordes appeared in this state, 

 eating everything in their course. They were reported again 

 present in more or less destructive numbers in 1830, 1842 and 

 in 1849; in 1855, 1856 and 1857; in 1863. 1864, 1865, 1866. 1867, 



