THE AMERICAN ENTOMOLOGIST. 



83 



I agree with him in regard to the facts, I must 

 demur to some of the couclusions he draws 

 therefrom, in liis article on page 94 of your first 

 volume. 



"The greater tlie heat the more they flourish," 

 is true with most grasshoppers. And as a gen- 

 eral thing the drier the season the more abund- 

 ant will the troublesome species become. My 

 information accords with Mi-. Byers' statement 

 that the greatest injury is done by the broods 

 hatched on the plains. It seems to be a general 

 understanding in that section that when a heavy 

 fall swarm comes down from the mountains, 

 the next spring brood will be numerous and 

 destructive. But the inference he draws from 

 this fact, to-wit, that its native home is not in 

 the canons of the Rocky Mountains, but the hot 

 parclied plains and table lands, is not legiti- 

 mate. 



1. As shown from fads stated in his oton ar- 

 ticle. It is not likely tliat an insect whose native 

 breeding place is the hot parched plain, would 

 often be seen Hying across the cold snowy peaks 

 around Middle I'ark, a hundred miles distant 

 from the nearest western jjhvin of this character. 

 It is alio strange that the worst visitation of an 

 insect, 'native (o the hot parched plains in the 

 latitude ot Denver, should come from the val- 

 leys of the Upper Missouri, six or eight hundred 

 miles farther north, along the IJocky Mountain 

 range. It is apparent that Mr. Byers' theoi'y 

 will not agree wiih his facts. 



2. As shown by my own observations. The 

 present year (18G9), as will be admitted by all 

 observers, was not a migratory season with them 

 in Eastern Colorado, hence they would be seen 

 in their normal condition, or nearly so.* By 

 reference to my notes as given above, it will be 

 seen that while they appeared in comparatively 

 small numbers on tlic plains, they were abun- 

 dant and active in the mountain canons. 



1 camped in the valley immediately east of 

 the snowy rim of the Middle Park, near Ber- 

 tlioud Pass, for six days (July 21-27). This is 

 a narrow valley with a snow-capped range on 

 each side ; the bottom, as marked near the mar- 

 gin of tiie clear cold creek, nine thousand live 

 hundred feet above the level of the sea. Here 

 day after day I watched these insects rising and 

 tilling tlie air like Hakes of snow in a winter 

 storm. Turning their lieads against the wind 

 as they arose, they were borne backwards by 

 the wind, which seemed to be their only method 

 of making long flights. Hence I think Mr. 



♦I ussurac as grunted that tin' iiic.riuoiis UcvdoiJim-nt of 

 liny species of insi'Ct, as the Mi^'iMiui y l/nust. Army Worm, 

 etc., are aberrjitious from tlieit- iioniinl t-ondition, superin- 

 duced by a combination of favorable iiillmiices. 



Byers is correct in saying that " their course is 

 directed by the prevailing winds more than by 

 any other influence." And as he says, each in- 

 dividual seemed to move on it.s owu account 

 and not in concert, the atmospheric and other 

 influences inducing them to rise at the same 

 time. The strokes of their wings, together with 

 the wind — when not too strong — has a tendency 

 to carry them upwards. Rising to the tops of 

 the ranges Avith the local current, here they 

 enter into the upper current, which, moving 

 generally in an easterly direction, carries them 

 over on the plains. If the upper current is 

 strong and cold it has a tendency to chill them, 

 and if they pass close to the summit as they go 

 over the range, the flexure of the upper portion 

 dashes many of them on the snow which is 

 found in such places. Whether the heavier 

 atmosphere on the low plains enables them to 

 direct their course or not, is perhaps, a matter 

 yet undetermined. 



The pupa which I saw on the crest of the 

 range, and about which I am not mistaken, (I 

 think I saw others), shows that they hatch out 

 at great heights. Numbers both'of larvie and 

 pupas were seen on the mountain side. I traced 

 this species up the self-same rim, of which Mr. 

 Byers speaks, step by step to the snow, deci'eas- 

 iiig in numbers, of course, as I ascended, bnt 

 active to its very margin, and even above it on 

 the crest, and that there might be no mistake I 

 gathered specimens. I also searched carefully 

 for other species, but found very few specimens, 

 and these low down in the valley; though 

 on the ridges around the Boiling Springs, near 

 Colorado City, I found another species more 

 abundant than the sprdits. This latter species 

 I found in but few places, and always on 

 elevated points, and when it was present the 

 sjjretus was absent or very scarce. 



I will call attention here to a remark made by 

 Say which bears on the subject and confirms 

 the statement in regard to broods hatched ex- 

 terior to the mountains. It is found in his 

 report of Ilemipterous Insects collected during 

 Maj. Long's Expedition, under Gryllus bivit- 

 tatus (Ent. Lc C. II., 2.S8). '-This species, 

 with several others, occurred in great numbers 

 near the mountains, and on one occasion we 

 observed this species, with several others, 

 ascending to a great height in the air as if to 

 commence a migration to a remote region." 



I am clearly of the opinion that the native 

 abode and breeding place of this insect is in the 

 mountain valleys and canons, and that in Colo- 

 rado the direction of its flight is governed by the 

 wind. It is also certain that those seen at St. 



