CORRESP ONDENCE. 



613 



show that I am not the only one who has 

 noticed an abundance of Hymenoptera in 

 Colorado, I would call your attention to the 

 papers of Mr. E. T. Cressen in the " Pro- 

 ceedings of the Entomological Society of 

 Philadelphia," and particularly to a " Cata- 

 logue of Hymenoptera from Colorado Ter- 

 ritory," published in vol. iv. of those "Pro- 

 ceedings." 



Lepidoptep.a. In the list referred to 

 I have enumerated forty-seven species of 

 butterflies, which I collected, with but one 

 exception, in the mountains. I have never 

 anywhere seen butterflies so abundant as 

 they were in the valley of Clear Creek, be- 

 tween Golden City and Idaho Springs, on 

 July 1, 1872. The air seemed literally to 

 swarm with them. I cannot imagine how 

 the entomologists of Mr. Meehan's party 

 found them so scarce. Wherever there 

 were flowers, I was sure to find butterflies, 

 though, of course, they showed a prefer- 

 ence to some kinds. Of the Heterocera I 

 brought home over sixty species, mostly 

 undetermined; but this is no indication of 

 the actual number occurring, for I took no 

 pains to hunt them, and only preserved 

 what came to me. 



The common morning lined sphinx 

 {Deilephila lineatd) was frequently seen at 

 dusk, hovering about various flowers, being 

 especially fond of the yellow thistles. I do 

 not now recall any peculiarity regarding 

 the other species, except that they were 

 Cjirite plenty. Perhaps 1872 was an unusu- 

 ally favorable season ; but Mr. Theodore 

 L. Mead writes that in 1871 he spent four 

 months in Colorado, mostly in the South 

 Park region, where he collected over 100 

 species and 3,000 specimens of butterflies, 

 and 4,000 specimens of beetles, etc. I 

 believe Mr. Mead has published an account 

 of his observations on Colorado butterflies 

 in the zoological report of Lieutenant 

 Wheeler's explorations west of the 100th 

 meridian. I would also refer you to an 

 article on Coloradian butterflies, by Tryon 

 Reakirt, in the " Proceedings of the Ento- 

 mological Society of Philadelphia," vol. vi., 

 1866, and to the more recent works of W. 



ft 



H. Edwards, and others. 



Although Mr. Meehan does not mention 

 them, I have an idea that the Coleoplera 



and Hemiptera are often quite active agents 

 in the fertilization of plants. Certainly the 

 number of species of these orders found in 

 flowers was very great, and it is more than 

 likely that in 'going from flower to flower 

 they carry some of the pollen with them. 

 The Meloidce, Chrysomelidce, Cerambycidw, 

 Cleridce, Malachidce, Mordellidcs, etc., were 

 especially noticeable by the large number 

 of species and individuals. Trichodes or- 

 natus (Say) was exceedingly abundant in 

 the flowers of Potentilla Jtssa, and, after that 

 had generally gone out of flower, on the 

 flowers of the white and red geraniums and 

 other plants. Owing to the fact that at the 

 time I made these collections I knew the 

 names of neither the plants nor insects, I 

 cannot now remark more definitely on their 

 habits. A full list of the species collected 

 will be found in the "Proceedings of the 

 Davenport Academy," vol. i. 



I think what I have said shows that 

 there is no unusual scarcity of insects in 

 the Rocky Mountains of Colorado, at least 

 wherever there are flowers. It should not 

 be overlooked, however, that within the 

 Rocky Mountain regions there are arid 

 districts where neither insects nor flowers 

 are particularly abundant ; and also that a 

 similar state of affairs exists in a dense pine 

 or spruce forest. Wherever flowers are 

 plenty in the Rocky Mountains, so are in- 

 sects always ; but the reverse is often not 

 true, for I have frequently known certain 

 insects to be exceedingly plentiful where 

 there were no flowers. The "entcmolo- 

 gista " of Mr. Meehan's party were certain- 

 ly very unfortunate in finding so few insects. 

 I believe Mr. Morrison, of Cambridge, an 

 excellent collector, intends spending next 

 summer collecting the insects of Colorado, 

 and he will be able to add his testimony to 

 the case. 



Mr. Meehan has certainly read Lieu- 

 tenant Carpenter's paper in Hayden's Re- 

 port for 1873 very carelessly, or he would 

 have seen that the five species of butterflies 

 he speaks of as being the " doings of a 

 whole season " were all Alpine, and collect- 

 ed above the timber-line, a region which a 

 little further on he rules out of the discus- 

 sion. It is certainly true that these Alpine 

 " Lepidoptera are undoubtedly peculiar to 

 high latitudes and great elevations ; " but 



