190 THE CANADIAN ENTOMOLOGIST. 



over the higher portions of the plains lying to the eastward of the Rocky 

 Mountains, in the States of Wyoming, Colorado and New Mexico. This 

 insect, as ascertained from inquiry, covered an area of about 400 square 

 miles of territory in sufficient numbers to materially injure the grasses 

 growing on -the ranges of the entire region — and amongst these grasses, 

 the species of Bouteloiia., or Gramma grasses, and the Buffalo grass, 

 Buchloe dactyloides, seemed to be the most attacked, grains and other 

 cultiyated plants not appearing to be especially attractive to it. In fact 

 very little or no injury was done by it to the cultivated crops growing 

 within the region infested. About the same time that I was investigating 

 this insect upon its northern line of injury, Profs. Snow and Popenoe 

 were studying the same insect upon the southern border of its range, and 

 they found practically the same food-habits there that I had noted in 

 the north, and, by enquiry, found that the insects had come into that coun- 

 try from the south last fall, and had laid their eggs over a large area. 

 This year when the eggs hatched, the young began to move from their 

 breeding centres in all directions, seeking open places and the edges of 

 ploughed fields, and following roadways. This trait of seeking open spots 

 this season is probably due to the habit of the insect of naturally living 

 on open ground where grasses are short and scattered. The present 

 year was very wet in this particular region and caused an undergrowth of 

 grasses, hence the desire to find the natural conditions under which the 

 insect lives. The young began moving and finding these open places, 

 there congregated. Having thus gathered together in large numbers, they 

 must feed, and they naturally swept the grasses clean around these spots; 

 so noticeable was this in certain spots where they had gathered about the 

 hills of a species of ant which raises mounds of small gravel and cuts 

 away the vegetation for some distance around them, they had enlarged 

 these areas, in some places for fully half an acre. This year Messrs. Snow 

 and Popenoe observed them flying southward with such ease, by reason 

 of their long wings, that they resembled birds. 



Dissosteira obliterata, Thomas. Closely related to the above and 

 very similar in appearance to it, is a second species of these large, long- 

 winged locusts, which was found in injurious numbers along with Cammila 

 pellucida in Idaho last year. It was quite common in the Wood River 

 county lying north of Shoshone, and in the vicinity of Boise City, Idaho. 

 One form of this species was described by Saussure as Dissosteira spur- 

 cata in his " Prodromus (Tldipodorum ". This is not the GLdipoda oblit- 

 ata of Stoll. 



