602 RErORT UNITED STATES GEOLOGICAL SURVEY. 



borders of Utah were approached, insects (but not the locust) became 

 abundant. The locust, lio^vever, breeds as abundantly in Wyoming as in 

 adjacent Territories, and is evidently one of the sources of supply for 

 the swarms wbicli invade Colorado. In proof of this I will first quote 

 Professor Thomas, who makes the following statement in Haydeu's An- 

 nual Keport for 187G on the Geology of Wyoming: 



Duriug the expedition of the present year, while traveling ap the North Platte, 

 ber.weeu Fort Fetteruian and Red Biittes (Angust 20-'4o), we observed vast numbers 

 of this species. They were not on the wiujr, liaving to all appearances ended tlieir 

 lliglit, and were now pairing, doubtless intending to deposit their eggs there. Fr(5aiont 

 encountered a similar swarm in ])assing over this ])art of the North Platte Valley. Ho 

 remarks: "This insect has been so numerous since leaving Fort Laramie that the 

 ground seemed alive with them; and in walking a little moving cloud i)receded our 

 footsteps. They had probably ceased their flight, and were preparing to deposit their 

 eggs. By reference to my present rejiort oo the agriculture of this section it will he 

 seen that bore there appears to be an almost constant current of air sweeping down 

 the Platte Valley from the west. When we reached South Pass City, I learned from 

 Major Baldwin that about the first of the month (August) a large swarm had crossed 

 over the i)ass from the west, moving eastward, and that they had not gone to Wind 

 River Valley. I am satistied that tliey did not go upon the Laramie Plains, as I visited 

 that section twice during the season. Nor did we meet with any swani:s during our 

 passage up the Swt-etwater; we may, theiel'ore, reasonably infer that those we saw 

 on the North Platte were the same that crossed the mountains at South Pass. From 

 whence did they come? As we heard nothing of them during onr passage down Big 

 Sandy along the stage-road, I infer that they must have come from the northwest ; but 

 what distance I have uo means of ascertaining." 



Capt. W. J. Jones states in his ''Report upon the Reconnaissance of 

 Northwestern Wyoming," made in the summer of 1873, that in the Green 

 River Basin " the region is infested with gieat swarms of grasshoppers." 

 We have seen that Mr. Byers surmises that some of the swarms which 

 devastate Colorado cross the Snowy Range from the Green River Val- 

 ley. 



, THE LOCUST IN UTAH. 



This Territory is much freer from the invasions of locusts than 

 Colorado. In 1875 they were scarce, and had not been abundant for 

 three years, all that were seen being evidently indigenous. In gardens 

 in Salt Lake City, and in fields at Lake Point, in Salt Lake, in July, 

 1875, they were less frequent than the yellow-striped grasshopper (Cal- 

 optcnns flavovittatus). 1 found them not unfrequently in Utah, though 

 Mr. J. D. Putnam remarks : " In Utah last summer (1875) I failed to see 

 a single specimen, although 1 looked specially for it." (Proc. Daven- 

 port Academy of Sciences, 2GG.) The invasions, as several persons told 

 me, are from the north and northwest, the latter being the direction of 

 the prevailing winds in summer. The swarms coming down from the 

 north are sometimes turned back by the south winds, and when the 

 wind changes over Salt Lake multitudes are drowned. The gulls, so 

 common on the lake,were seen feeding on grasshoppers along the beaches. 

 Galoptenus spretus is undoubtedly distributed over the entire Territory. 

 Mr. J, L. Baribot, of Salt Lake City, in charge of the museum, told me 

 that he had received specimens (which 1 saw in the museum) from Ka- 

 uab, in Southeastern Utah, and also from Dirty Devil Mountain. Pro- 

 fessor Thomas also reports it as breeding in the southern and western 

 line of Utah. In his letter to me Mr. Byers states that he first saw the 

 locust in 1852, about the 1st of August, upon the plains of Northern 

 Utah and Southern Idaho. Professor Thomas also gives the following- 

 data regarding its occurrence in Utah, in Haydeu's Report on the Geol- 

 ogy of Wyoming, 1870, p. 283: 



As heretofore stated, they have been very destructive in Utah for the past three 

 years, not only injuring very materially the growing crops, but eating the leaves from 



