CAEPENTEB.] ZOOLOGY ^ALPINE INSECT-FAUNA. 539 



their hammering and pecking proclivities in search of larva3, as these 

 birds are by no means abnndant in that regiou. 



The section of country most affected seems to be the mountains near 

 the source of Twin Lake Creek and the branches of the Gunnison 5 it 

 was not noticed in Middle Park and Northern Colorado. The damage 

 is so considerable that in a walk of one mile through a deuse pine-for- 

 est on Twin Lake Creek, sixty large trees were counted, dead, or fast 

 losing their vitality from this cause. 



EEPOET ON THE ALPINE INSECT-FAUNA OF COLORADO. 



By Lieut. W. L. Carpenter, U. S. A. 



A separate entomological collection was made by myself over an 

 extensive area, at extreme elevations, in all cases exceeding an altitude 

 of 12,000 feet above the level of the sea. Here amid the region of 

 eternal snow, where both the animal and vegetable kingdoms, exposed to 

 a climate of arctic severity, seem struggling for existence, are found 

 many lowly forms of life, extremely interesting from their peculiar 

 choice of a home. Only a short distance below the timber-line, at an 

 altitude of about 11,000 feet, insect-life may be found in abundance ; 

 but an ascent of a few hundred feet causes a wonderful diminution in 

 species ; and when the summits of the loftiest peaks are reached, at an 

 altitude greater than 14,000 feet, unless the weather be unusually mild, 

 it requires very close scrutiny to disclose the presence of any life. It 

 is probable that some insects, such as the Orthoptera^ a few Hemiptera, 

 Dijjtera, and Coccinellidce, are carried to the tops of mountains by 

 storms and atmospheric currents; while the Arachnida,-Le2ndoptera, Neu- 

 roptera, and most Coleoptera, many of which have been found in Alaska 

 and Labrador, are undoubtedly peculiar to high latitudes and great 

 elevations. In the early spring, long before any bare ground was visi- 

 ble, Goccinella transversogutta and Lygceus recUvatus were found at an 

 elevation of 14,000 feet, in abundance upon the surface of the snow. 

 Lygcmis reclivatus seemed to be widely distributed ; it being always 

 found above the timber-belt, from May to October, throughout an area 

 of 20,000 square miles. By removing the snow and searching under 

 stones and in moss, Arachnida, Goleoptera, and larvae were found. A 

 microscopic examination of snow-water collected in pools, made during 

 the months of May and June, failed to reveal the existence of any ani- 

 mal life ; and it was then thought that aquatic insects would not be 

 found 5 but a shallow jjool discovered on Elbert Peak above timber-line, 

 July 22, proved to contain considerable life, and was especially produc- 

 tive of a species of Entomostraca. 



Myriads of grasshoppers of the species Caloptenus spretus swarm from 

 the Pacific slope in the months of July and August, and in their journey 

 eastward are arrested by the high peaks and ridges of the Rocky 

 Mountains, and, becoming benumbed by cold, drop down to perish. 

 The barrier thus presented by these mountains is of great benefit to the 

 agricultural interest of Colorado ; for, although upon a favorable sea- 

 son some swarms may -pass by to the eastern plains, it will be safe, to 

 estimate that not more than one-tenth of the number which rise from 

 the plains and valleys of Utah ever succeed in crossing the divide. 



Five species of butterflies were found ; the Parnassius Smintheus and 



