12 REPORTS OF OBSERVATIONS AND EXPERIMENTS. 



used at various times in the past in different countries and under divers 

 conditions in fighting the locust pests of the world. In connection 

 with the remarks made, charts were exhibited showing the differences 

 among the species committing these injuries against which relief had 

 been sought. Both the practical remedies, or such as can be applied with 

 a saving, and the impractical remedies, or such as cost more to apply than 

 would be the value of the crops intended to be saved, were described 

 at some length. It is needless to say that I favored the practical rem- 

 edies, although there were many among the audiences who insisted upon 

 the adoption 6f some remedy where there would be little or no outlay of 

 labor. Nevertheless the " practical" methods were insisted upon by me 

 since the people were not overburdened with cash to such an extent 

 that they could afford to go into a series of doubtful experiments at 

 this late date of the trouble. 



Every circumstance seemed to favor the use of the hopper-dozers at 

 this time. - Prior to my arrival the citizens of Grand Junction had 

 secured a 10,000-galion tank of crude petroleum for use in destroying 

 the 'hoppers. This, as I afterwards ascertained, was intended to be 

 used for pouring into the irrigating ditches and allowing it to spread 

 over the country so as to come in contact (?) with the insects which it 

 was intended to destroy. In my addresses I insisted that this would 

 only be throwing the material away and would also destroy the vege- 

 tation wherever the oil reached, and that the locust would be mostly 

 left unharmed. We tried the oil in the 'hopper-dozers and were sur- 

 prised at the results. It worked much better,if possible, than the refined 

 oil, and its cost was so very much less, being only 4 cents per gallon 

 delivered at Grand Junction, that its use in this connection could be 

 highly recommended. The comparative thickness made it more desira- 

 ble because of its remaining in the pan to better advantage. It could 

 even be cheapened by adding water to the oil in the pan on the dozers. 



There were several species of locusts concerned in the depredations 

 in and about Grand Junction, as well as at other x>oints in the surround- 

 ing regions of Colorado. I found Melanoplus atlanis, M. bivittatus, 

 and M. differentialis in the fields of the region examined. There were 

 also several other species very numerous in the valley and upon the 

 surrounding hills wherever the vegetation was of sufficient size to sup- 

 port them. One was an undescribed species of Pezotettix, as these 

 insects have been classed by American writers, somewhat resembling 

 M. tumbulli Thos., only with very short and rounded tegmina. Like 

 M. tumbulli, it seems to be confined chiefly to species of the Chenopo- 

 diacea?, of which the region contains many forms. It is especially 

 fond of the greasewood (Sarcobates vermicular is). Peculiar enough 

 was the fact that on my arrival much of the preparation for defense 

 that was then under way was for the destruction of this Pezotettix? 

 that did none or very little of the injury that had thus far occurred in 

 the valley. I have proposed for this species the name Pezotettix clieno- 



