April, '12] GILLETTE: GRASSHOPPERS IN COLORADO 123 



face of the ground, where they are quickly killed by the action of the 

 sun, probably aided by frequent freezing and thawing. Wherever 

 it is possible to do so, I recommend deep plowing followed by thorough 

 harrowing and packing of the soil. In the alfalfa fields, our best 

 summer remedy seems to be the use of the hopper-dozer in one form 

 or another. The most popular dozer in northern Colorado is a long 

 box about one foot on each side with the top and back open and covered 

 with a screen. Along the front side of the box is a tin or sheet-iron 

 apron or shield against which the grasshoppers jump and are carried 

 down to a narrow opening at the bottom of the apron, through which 

 they enter the box, being attracted by the light at the top and back. 



In potato fields and about market gardens and orchards arsenic- 

 bran mash has been found to be quite efficient. We have not been 

 very successful in the use of arsenical sprays upon vegetation which 

 is being eaten by the grasshoppers. 



We have been carrying on a series of experiments during the past 

 year, for the purpose of determining more accurately and completely 

 the full life histories of our more destructive species, with special 

 reference to the egg-laying habits. 



Considerable work is being carried on with various remedies also 

 for the purpose of determining which are most efficient and practical 

 to recommend for use upon the farms of this locality. This work has 

 been in charge of Professor S. Arthur Johnson, who will report upon 

 his investigations sometime in the future. 



Adjourned. 



Thursday, December 28th, 1.30 P. M. 



Meeting called to order with President F. L. Washburn in chair. 



President F. L. Washburn: A paper by Mr. W. D. Hunter, on 

 "The outbreak of Alabama argillacea Hbn. in 1911." 



W^. D. Hunter: Mr. President and Members of the Association: 

 let me make the statement that this name, Alabama argillacea, is 

 nothing more nor less than a name for the cotton caterpillar leaf 

 worm. I shall restrict myself entirely to the manuscript. ♦ 



THE OUTBREAK OF ALABAMA ARGILLACEA IN 191 1 



By W. D. Hunter, Bureau of Entomology 



Undoubtedly one of the most interesting entomological occurrences 

 of 1911 in the United States was the great outbreak of Alabama argil- 

 lacea. After nearly a quarter of a century during which this insect 

 attracted practically no attention it suddenly appeared in extreme 



