THE MEASURES HEREIN DESCRIBED ARE APPLICABLE ALSO TO CLOVER CROPS. 



While this circuhir is primarily for the benefit of the alfalfa 

 grower, the measures of suppression recommended may be applied 

 in the clover fields of the eastern section of this country with equally 

 good results. Indeed, the two species here discussed are at times 

 destructively abundant in the red-clover fields of the Middle West, 

 and the writer has there used the " hopperdozer " to advantage. 



EARLY DEPREDATIONS. 



With the rapid increase in the culture of alfalfa throughout the 

 country west of the Mississippi River there has come the problem of 

 jjrotecting this crop from attacks of several species of grasshoppers 

 or locusts. The reason for this state of affairs is not at all obscure, 

 as in order to breed freely and in destructive numbers these grass- 

 hoppers require two conditions: First, an undisturbed soil for the 

 protection of their eggs after these have been deposited, and, second, 

 an early food supply for the young in spring. No other crop comes 

 so near supplying these conditions to an ideal degree as does alfalfa. 



Thus it is that the farmer in this section of the country has from 

 the beginning of alfalfa culture been sorely beset by these pests, 

 wdiose destructive hordes might even now be said to follow closely in 

 the footprints of the i-eclamation engineer. 



SERIOUSNESS OF INJURIES. 



Hardly a season passes during w-hich more or less serious outbreaks 

 are not reported in different localities, and the aid of this Bureau is 

 frequently invoked in destroying these grasshoppers or otherwise 

 lessening their ravages. Thus during the year 1905 1 such out- 

 break was reported from California, 7 from Colorado, 1 from Idaho, 

 10 from Kansas, 3 from New" Mexico, 2 from Utah, and 1 from 

 Texas. It is in no wise likely that these numbers indicate more than 

 a minor portion of the destructive outbreaks of these pests that 

 actually occurred over this territory, and the seriousness of some of 

 these outbreaks is indicated by the fact that as many as 12 complaints 

 were received from a single locality. In fact, the probabilities are 

 that, as this agricultural industry increases, the amount of injury in- 

 flicted by these insects will grcatlj^ increase in future unless measures 

 are taken to control them. 



DESCRIPTIONS OF THE TWO PRINCIPAL ALFALFA-AFFECTING SPECIES. 



The differential grasshopper (fig. 1) is about ih inches long, its 

 ■wings expand about 2i inches, and it is of a general bright yellowish- 

 green color. There is, however, a nearly black melanic form that does 



[Cir. 84] 



