32 



and other fruit pests, do these locusts appear to be present in abnormal 

 numbers. 



Just how long they have been on the increase, and to what cause or 

 combination of causes this increase should be attributed at this time, 

 was not learned. Out on the plains away from the foothills and the 

 irrigating ditches the large species mentioned in Bulletin 28 as the 

 "long-winged locust of the plains" (Dissosteira longipennis) seemed to 

 be the characteristic form. The Melanoplus fcsdus was also quite abun- 

 dant there. Near Denver ill. fcedus, M. atlanis, and M. bivittatus were 

 the forms concerned in the devastating work. At Fort Collins only M. 

 bivittatus seemed to be present in unusually large numbers, while farther 

 east and at a greater distance from the mountains M. fcediis and M. 

 atlanis became equally numerous. 



In this Colorado region of locust abundance the pest may be on the 

 decline, since at one point at least large numbers of them were destroyed 

 by the fungous disease known as Empusa gryllce. The good effects of 

 this disease were especialty marked in the vicinity of Brighton and the 

 neighboring towns along the Platte Eiver between Denver and Greeley. 

 At other points, however, the disease was not found, and the grasshop- 

 pers seemed quite healthy and remarkably free from natural enemies of 

 all kinds. 



The hopper-dozers could be used to very good advantage over most 

 of the region embraced in the above-mentioned locust area, and this 

 remedy was urged as the most expeditious as well as economical means 

 for ridding the region of the pest. The large alfalfa fields and edges of 

 irrigating ditches seem to have been the breeding places for the various 

 Melanopli, while the stony hillsides furnished a suitable place for the 

 increase of Dissosteira longipennis and several other barren -ground 

 species. The heavy rains and consequent rank growth of vegetation 

 on the plains has been the direct cause for the "bunching" and more 

 recently for the eastward and northward spreading of the long- winged 

 species (see Bull. 28, p. 38). From recent reports received from various 

 localities in Colorado and Nebraska it seems that this insect has 

 appeared over a large portion of both States. It has even reached as 

 far as the eastern boundary of Nebraska in considerable numbers. 



To the northward of this region, between Cheyenne, Wyo., and Orino 

 Junction, Wyo., where locusts of various species are usually quite 

 abundant, and where a few forms were reported as uncommonly abun- 

 dant during the summers of 1893 and 1894, this year but very few were 

 found. A ranchman, who lives in the vicinity of Wheatland, informed 

 me that the early opening of spring, followed by a series of cold rains 

 during the months of May and June, had killed the young locusts off* 

 before they had a chance to do any injury. Be this true or not, there 

 were scarcely any locusts to be found when I visited the region the 

 last of July. 



Going west from Cheyenne, a stop was made at Laramie City, from 



